From 0de861b2b90367ee48621dafb233a9917bbb3775 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Fri, 19 Feb 2021 20:50:10 -0600
Subject: [PATCH 01/26] quick WIP for GLSL transpose for the shakycam effect

---
 src/lib/gui/gl_2d_display.h | 32 +++++++++++++++++++++++++++-----
 src/lib/gui/window_glfw.h   |  6 ++++++
 2 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/src/lib/gui/gl_2d_display.h b/src/lib/gui/gl_2d_display.h
index 3a4cf5e5..c806500b 100644
--- a/src/lib/gui/gl_2d_display.h
+++ b/src/lib/gui/gl_2d_display.h
@@ -60,8 +60,13 @@ class gl_2d_display
 
 		// pass in rotation matrix
 		GLuint rotateUniform = glGetUniformLocation(prog, "rot");
-		std::array<GLfloat, 4> vals = rotation_matrix();
-		glUniformMatrix2fv(rotateUniform, 1, false, vals.data());
+		std::array<GLfloat, 4> rot = rotation_matrix();
+		glUniformMatrix2fv(rotateUniform, 1, false, rot.data());
+
+		// pass in transform vector
+		GLuint transformUniform = glGetUniformLocation(prog, "tform");
+		std::pair<float, float> tform = shake_transform();
+		glUniform2f(transformUniform, tform.first, tform.second);
 
 		// Draw
 		glDrawArrays(GL_TRIANGLES, 0, 6);
@@ -87,6 +92,12 @@ class gl_2d_display
 			_rotation = 0;
 	}
 
+	void shake(unsigned i=1)
+	{
+		if (i == 0 or ++_shake >= 8)
+			_shake = 0;
+	}
+
 	std::array<GLfloat, 4> rotation_matrix() const
 	{
 		// just using sin and cos is probably better?
@@ -95,15 +106,23 @@ class gl_2d_display
 			default:
 			case 0:
 				return {-1, 0, 0, 1};
-			case 1: // right 90
-				return {0, 1, 1, 0};
-			case 2: // right 180
+			case 1: // right 180
 				return {1, 0, 0, -1};
+			case 2: // right 90
+				return {0, 1, 1, 0};
 			case 3: // right 270
 				return {0, -1, -1, 0};
 		}
 	}
 
+	std::pair<float, float> shake_transform() const
+	{
+		static constexpr std::array<std::pair<float, float>, 8> SHAKE_POS = {{
+		    {0, 0}, {-.008, -.008}, {0, 0}, {.008, .008}, {0, 0}, {-.008, .008}, {0, 0}, {.008, -.008}
+		}};
+		return SHAKE_POS[_shake];
+	}
+
 protected:
 	static std::shared_ptr<cimbar::gl_program> create()
 	{
@@ -116,6 +135,7 @@ class gl_2d_display
 		*/
 		static const std::string VERTEX_SHADER_SRC = R"(#version 300 es
 		uniform mat2 rot;
+		uniform vec2 tform;
 		in vec4 vert;
 		out vec2 texCoord;
 		void main() {
@@ -123,6 +143,7 @@ class gl_2d_display
 		   vec2 ori = vec2(vert.x, vert.y);
 		   ori *= rot;
 		   texCoord = vec2(1.0f - ori.x, 1.0f - ori.y) / 2.0;
+		   texCoord += tform;
 		})";
 
 		static const std::string FRAGMENT_SHADER_SRC = R"(#version 300 es
@@ -145,6 +166,7 @@ class gl_2d_display
 	GLuint _vao;
 	unsigned _i = 0;
 	unsigned _rotation = 0;
+	unsigned _shake = 0;
 };
 
 }
diff --git a/src/lib/gui/window_glfw.h b/src/lib/gui/window_glfw.h
index d3cb358b..57a4df6a 100644
--- a/src/lib/gui/window_glfw.h
+++ b/src/lib/gui/window_glfw.h
@@ -61,6 +61,12 @@ class window_glfw : public window_interface<window_glfw>
 			_display->rotate(i);
 	}
 
+	void shake(unsigned i=1)
+	{
+		if (_display)
+			_display->shake(i);
+	}
+
 	void clear()
 	{
 		if (_display)

From cb84a5924fbf5636d351730c105dced88173311a Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Fri, 19 Feb 2021 21:18:55 -0600
Subject: [PATCH 02/26] hmm

(still using the shaky_cam object, though its days are likely numbered)
---
 src/exe/cimbar_send/send.cpp | 10 ++++------
 src/lib/gui/gl_2d_display.h  |  3 ++-
 src/lib/gui/window_glfw.h    |  1 +
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/exe/cimbar_send/send.cpp b/src/exe/cimbar_send/send.cpp
index f20aeb51..3c9ded5c 100644
--- a/src/exe/cimbar_send/send.cpp
+++ b/src/exe/cimbar_send/send.cpp
@@ -60,11 +60,7 @@ int main(int argc, char** argv)
 	bool use_shakycam = result.count("shakycam");
 
 	cimbar::shaky_cam cam(cimbar::Config::image_size(), 1080, 1080, dark);
-	// if we don't need the shakycam, we'll just turn it off
-	// we could use a separate code path (just do a mat copyTo),
-	// but this is fine.
-	if (!use_shakycam)
-		cam.toggle();
+	cam.toggle();
 
 	cimbar::window w(cam.width(), cam.height(), "cimbar_send");
 	if (!w.is_good())
@@ -76,7 +72,7 @@ int main(int argc, char** argv)
 	bool running = true;
 	bool start = true;
 
-	auto draw = [&w, &cam, use_rotatecam, delay, &running, &start] (const cv::Mat& frame, unsigned) {
+	auto draw = [&w, &cam, use_rotatecam, use_shakycam, delay, &running, &start] (const cv::Mat& frame, unsigned) {
 		if (!start and w.should_close())
 			return running = false;
 		start = false;
@@ -85,6 +81,8 @@ int main(int argc, char** argv)
 		w.show(windowImg, delay);
 		if (use_rotatecam)
 			w.rotate();
+		if (use_shakycam)
+			w.shake();
 		return true;
 	};
 
diff --git a/src/lib/gui/gl_2d_display.h b/src/lib/gui/gl_2d_display.h
index c806500b..5f62a48d 100644
--- a/src/lib/gui/gl_2d_display.h
+++ b/src/lib/gui/gl_2d_display.h
@@ -117,8 +117,9 @@ class gl_2d_display
 
 	std::pair<float, float> shake_transform() const
 	{
+		const float step = .007407407f;  // 8 / 1080
 		static constexpr std::array<std::pair<float, float>, 8> SHAKE_POS = {{
-		    {0, 0}, {-.008, -.008}, {0, 0}, {.008, .008}, {0, 0}, {-.008, .008}, {0, 0}, {.008, -.008}
+		    {0, 0}, {-step, -step}, {0, 0}, {step, step}, {0, 0}, {-step, step}, {0, 0}, {step, -step}
 		}};
 		return SHAKE_POS[_shake];
 	}
diff --git a/src/lib/gui/window_glfw.h b/src/lib/gui/window_glfw.h
index 57a4df6a..9529a2bf 100644
--- a/src/lib/gui/window_glfw.h
+++ b/src/lib/gui/window_glfw.h
@@ -30,6 +30,7 @@ class window_glfw : public window_interface<window_glfw>
 			return;
 		}
 		glfwMakeContextCurrent(_w);
+		glfwSwapInterval(1);
 
 		_display = std::make_shared<cimbar::gl_2d_display>();
 		glGenTextures(1, &_texid);

From d869656f072ba8d1683a66922def80739beee185 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Fri, 19 Feb 2021 21:43:15 -0600
Subject: [PATCH 03/26] use loop_iterator?

Not sure where the magical "shake" calculation should live -- it's tied
to the shader, but feels weird to prop out into the window_* classes.

Might pass in the dimensions to gl_2d_display(), it kinda makes sense
for it to have them
---
 src/lib/gui/gl_2d_display.h | 62 ++++++++++++++++---------------------
 src/lib/gui/window_glfw.h   |  3 +-
 2 files changed, 29 insertions(+), 36 deletions(-)

diff --git a/src/lib/gui/gl_2d_display.h b/src/lib/gui/gl_2d_display.h
index 5f62a48d..8570b7c7 100644
--- a/src/lib/gui/gl_2d_display.h
+++ b/src/lib/gui/gl_2d_display.h
@@ -3,6 +3,7 @@
 
 #include "gl_program.h"
 #include "gl_shader.h"
+#include "util/loop_iterator.h"
 
 #include <GLES3/gl3.h>
 #include <GLES2/gl2ext.h>
@@ -23,9 +24,20 @@ class gl_2d_display
 	    -1.0f,  1.0f, 0.0f
 	};
 
+	// just using sin and cos is probably better?
+	static constexpr std::array<std::array<GLfloat, 4>, 4> ROTATIONS = {{
+	    {-1, 0, 0, 1},
+	    {1, 0, 0, -1}, // right 180
+	    {0, 1, 1, 0},  // right 90
+	    {0, -1, -1, 0} // right 270
+	}};
+
 public:
-	gl_2d_display()
+	gl_2d_display(float shake=0)
 	    : _p(create())
+	    , _shakePos{{ {0, 0}, {-shake, -shake}, {0, 0}, {shake, shake}, {0, 0}, {-shake, shake}, {0, 0}, {shake, -shake} }}
+	    , _shake(_shakePos)
+	    , _rotation(ROTATIONS)
 	{
 		glGenBuffers(3, _vbo.data());
 		glGenVertexArrays(1, &_vao);
@@ -60,12 +72,12 @@ class gl_2d_display
 
 		// pass in rotation matrix
 		GLuint rotateUniform = glGetUniformLocation(prog, "rot");
-		std::array<GLfloat, 4> rot = rotation_matrix();
+		std::array<GLfloat, 4> rot = *_rotation;
 		glUniformMatrix2fv(rotateUniform, 1, false, rot.data());
 
 		// pass in transform vector
 		GLuint transformUniform = glGetUniformLocation(prog, "tform");
-		std::pair<float, float> tform = shake_transform();
+		std::pair<GLfloat, GLfloat> tform = *_shake;
 		glUniform2f(transformUniform, tform.first, tform.second);
 
 		// Draw
@@ -88,40 +100,18 @@ class gl_2d_display
 
 	void rotate(unsigned i=1)
 	{
-		if (i == 0 or ++_rotation >= 4)
-			_rotation = 0;
+		if (i == 0)
+			_rotation.reset();
+		else
+			++_rotation;
 	}
 
 	void shake(unsigned i=1)
 	{
-		if (i == 0 or ++_shake >= 8)
-			_shake = 0;
-	}
-
-	std::array<GLfloat, 4> rotation_matrix() const
-	{
-		// just using sin and cos is probably better?
-		switch (_rotation)
-		{
-			default:
-			case 0:
-				return {-1, 0, 0, 1};
-			case 1: // right 180
-				return {1, 0, 0, -1};
-			case 2: // right 90
-				return {0, 1, 1, 0};
-			case 3: // right 270
-				return {0, -1, -1, 0};
-		}
-	}
-
-	std::pair<float, float> shake_transform() const
-	{
-		const float step = .007407407f;  // 8 / 1080
-		static constexpr std::array<std::pair<float, float>, 8> SHAKE_POS = {{
-		    {0, 0}, {-step, -step}, {0, 0}, {step, step}, {0, 0}, {-step, step}, {0, 0}, {step, -step}
-		}};
-		return SHAKE_POS[_shake];
+		if (i == 0)
+			_shake.reset();
+		else
+			++_shake;
 	}
 
 protected:
@@ -166,8 +156,10 @@ class gl_2d_display
 	std::array<GLuint, 3> _vbo;
 	GLuint _vao;
 	unsigned _i = 0;
-	unsigned _rotation = 0;
-	unsigned _shake = 0;
+
+	std::array<std::pair<GLfloat, GLfloat>, 8> _shakePos;
+	loop_iterator<decltype(_shakePos)> _shake;
+	loop_iterator<decltype(ROTATIONS)> _rotation;
 };
 
 }
diff --git a/src/lib/gui/window_glfw.h b/src/lib/gui/window_glfw.h
index 9529a2bf..1085a1e8 100644
--- a/src/lib/gui/window_glfw.h
+++ b/src/lib/gui/window_glfw.h
@@ -32,7 +32,8 @@ class window_glfw : public window_interface<window_glfw>
 		glfwMakeContextCurrent(_w);
 		glfwSwapInterval(1);
 
-		_display = std::make_shared<cimbar::gl_2d_display>();
+		float shake = 8.0 / std::min(width, height);
+		_display = std::make_shared<cimbar::gl_2d_display>(shake);
 		glGenTextures(1, &_texid);
 		init_opengl(width, height);
 	}

From 355ef7c90e1fbf811cf2bfb416139f20511c32f2 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Fri, 19 Feb 2021 21:52:39 -0600
Subject: [PATCH 04/26] Is this better?

---
 src/lib/gui/gl_2d_display.h | 10 ++++++++--
 src/lib/gui/window_glfw.h   |  3 +--
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/lib/gui/gl_2d_display.h b/src/lib/gui/gl_2d_display.h
index 8570b7c7..3386f33c 100644
--- a/src/lib/gui/gl_2d_display.h
+++ b/src/lib/gui/gl_2d_display.h
@@ -32,10 +32,16 @@ class gl_2d_display
 	    {0, -1, -1, 0} // right 270
 	}};
 
+	static std::array<std::pair<GLfloat, GLfloat>, 8> computeShakePos(unsigned dim)
+	{
+		float shake = 8.0f / dim;
+		return {{ {0, 0}, {-shake, -shake}, {0, 0}, {shake, shake}, {0, 0}, {-shake, shake}, {0, 0}, {shake, -shake} }};
+	}
+
 public:
-	gl_2d_display(float shake=0)
+	gl_2d_display(unsigned width, unsigned height)
 	    : _p(create())
-	    , _shakePos{{ {0, 0}, {-shake, -shake}, {0, 0}, {shake, shake}, {0, 0}, {-shake, shake}, {0, 0}, {shake, -shake} }}
+	    , _shakePos(computeShakePos(std::min(width, height)))
 	    , _shake(_shakePos)
 	    , _rotation(ROTATIONS)
 	{
diff --git a/src/lib/gui/window_glfw.h b/src/lib/gui/window_glfw.h
index 1085a1e8..03091224 100644
--- a/src/lib/gui/window_glfw.h
+++ b/src/lib/gui/window_glfw.h
@@ -32,8 +32,7 @@ class window_glfw : public window_interface<window_glfw>
 		glfwMakeContextCurrent(_w);
 		glfwSwapInterval(1);
 
-		float shake = 8.0 / std::min(width, height);
-		_display = std::make_shared<cimbar::gl_2d_display>(shake);
+		_display = std::make_shared<cimbar::gl_2d_display>(width, height);
 		glGenTextures(1, &_texid);
 		init_opengl(width, height);
 	}

From f6b64960499129fbe10ce97b02e3b23b9d840063 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Sat, 20 Feb 2021 00:46:24 -0600
Subject: [PATCH 05/26] I don't know about this one chief

---
 src/exe/cimbar_send/send.cpp | 10 +++-------
 src/lib/gui/gl_2d_display.h  | 30 ++++++++++++++++++++++++------
 src/wasm/cimbar_js/wasm.cpp  |  2 +-
 web/main.js                  |  6 +++---
 4 files changed, 31 insertions(+), 17 deletions(-)

diff --git a/src/exe/cimbar_send/send.cpp b/src/exe/cimbar_send/send.cpp
index 3c9ded5c..7cdcf87b 100644
--- a/src/exe/cimbar_send/send.cpp
+++ b/src/exe/cimbar_send/send.cpp
@@ -59,10 +59,7 @@ int main(int argc, char** argv)
 	bool use_rotatecam = result.count("rotatecam");
 	bool use_shakycam = result.count("shakycam");
 
-	cimbar::shaky_cam cam(cimbar::Config::image_size(), 1080, 1080, dark);
-	cam.toggle();
-
-	cimbar::window w(cam.width(), cam.height(), "cimbar_send");
+	cimbar::window w(1080, 1080, "cimbar_send");
 	if (!w.is_good())
 	{
 		std::cerr << "failed to create window :(" << std::endl;
@@ -72,13 +69,12 @@ int main(int argc, char** argv)
 	bool running = true;
 	bool start = true;
 
-	auto draw = [&w, &cam, use_rotatecam, use_shakycam, delay, &running, &start] (const cv::Mat& frame, unsigned) {
+	auto draw = [&w, use_rotatecam, use_shakycam, delay, &running, &start] (const cv::Mat& frame, unsigned) {
 		if (!start and w.should_close())
 			return running = false;
 		start = false;
 
-		cv::Mat& windowImg = cam.draw(frame);
-		w.show(windowImg, delay);
+		w.show(frame, delay);
 		if (use_rotatecam)
 			w.rotate();
 		if (use_shakycam)
diff --git a/src/lib/gui/gl_2d_display.h b/src/lib/gui/gl_2d_display.h
index 3386f33c..1969ad25 100644
--- a/src/lib/gui/gl_2d_display.h
+++ b/src/lib/gui/gl_2d_display.h
@@ -8,6 +8,7 @@
 #include <GLES3/gl3.h>
 #include <GLES2/gl2ext.h>
 
+#include <iostream>
 #include <memory>
 
 namespace cimbar {
@@ -32,16 +33,27 @@ class gl_2d_display
 	    {0, -1, -1, 0} // right 270
 	}};
 
-	static std::array<std::pair<GLfloat, GLfloat>, 8> computeShakePos(unsigned dim)
+	static std::array<std::pair<GLfloat, GLfloat>, 8> computeShakePos(float dim)
 	{
-		float shake = 8.0f / dim;
-		return {{ {0, 0}, {-shake, -shake}, {0, 0}, {shake, shake}, {0, 0}, {-shake, shake}, {0, 0}, {shake, -shake} }};
+		float shake = 8.0f / dim; // 1080
+		float zero = (dim - 1000.0) / (dim*2);
+		return {{
+			{zero, zero},
+			{zero-shake, zero-shake},
+			{zero, zero},
+			{zero+shake, zero+shake},
+			{zero, zero},
+			{zero-shake, zero+shake},
+			{zero, zero},
+			{zero+shake, zero-shake}
+		}};
 	}
 
 public:
 	gl_2d_display(unsigned width, unsigned height)
 	    : _p(create())
-	    , _shakePos(computeShakePos(std::min(width, height)))
+	    , _dimension(std::min(width, height))
+	    , _shakePos(computeShakePos(_dimension))
 	    , _shake(_shakePos)
 	    , _rotation(ROTATIONS)
 	{
@@ -76,6 +88,10 @@ class gl_2d_display
 		glBindTexture(GL_TEXTURE_2D, texture);
 		glUniform1i(textureUniform, 0);
 
+		// scaling
+		GLuint scalingUniform = glGetUniformLocation(prog, "scaling");
+		glUniform1f(scalingUniform, 2 * (1008 / _dimension));
+
 		// pass in rotation matrix
 		GLuint rotateUniform = glGetUniformLocation(prog, "rot");
 		std::array<GLfloat, 4> rot = *_rotation;
@@ -133,14 +149,15 @@ class gl_2d_display
 		static const std::string VERTEX_SHADER_SRC = R"(#version 300 es
 		uniform mat2 rot;
 		uniform vec2 tform;
+		uniform float scaling;
 		in vec4 vert;
 		out vec2 texCoord;
 		void main() {
 		   gl_Position = vec4(vert.x, vert.y, 0.0f, 1.0f);
 		   vec2 ori = vec2(vert.x, vert.y);
 		   ori *= rot;
-		   texCoord = vec2(1.0f - ori.x, 1.0f - ori.y) / 2.0;
-		   texCoord += tform;
+		   texCoord = vec2(1.0f - ori.x, 1.0f - ori.y) / scaling;
+		   texCoord -= tform;
 		})";
 
 		static const std::string FRAGMENT_SHADER_SRC = R"(#version 300 es
@@ -162,6 +179,7 @@ class gl_2d_display
 	std::array<GLuint, 3> _vbo;
 	GLuint _vao;
 	unsigned _i = 0;
+	float _dimension;
 
 	std::array<std::pair<GLfloat, GLfloat>, 8> _shakePos;
 	loop_iterator<decltype(_shakePos)> _shake;
diff --git a/src/wasm/cimbar_js/wasm.cpp b/src/wasm/cimbar_js/wasm.cpp
index ce6a958b..5c33dd96 100644
--- a/src/wasm/cimbar_js/wasm.cpp
+++ b/src/wasm/cimbar_js/wasm.cpp
@@ -65,7 +65,7 @@ int render()
 	}
 
 	_window->show(*img, 0);
-	_window->rotate();
+	_window->shake();
 	return ++_renders;
 }
 
diff --git a/web/main.js b/web/main.js
index eaca534c..6f7894d1 100644
--- a/web/main.js
+++ b/web/main.js
@@ -33,7 +33,7 @@ return {
   {
     console.log("init for canvas " + canvas);
 
-    Module._initialize_GL(1024, 1024);
+    Module._initialize_GL(1040, 1040);
     Main.scaleCanvas(canvas, width, height);
     Main.alignInvisibleClick(canvas);
   },
@@ -45,8 +45,8 @@ return {
       dim = height;
     }
     console.log(dim);
-    if (dim > 1024) {
-      dim = 1024;
+    if (dim > 1040) {
+      dim = 1040;
     }
     canvas.style.width = dim + "px";
     canvas.style.height = dim + "px";

From 396939a90853f0c319baac26027473d53167adaf Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Sat, 20 Feb 2021 02:10:05 -0600
Subject: [PATCH 06/26] It's something like this, but...

---
 src/lib/gui/gl_2d_display.h | 18 ++++++++++--------
 src/lib/gui/window_glfw.h   |  2 +-
 src/wasm/cimbar_js/wasm.cpp |  4 ++--
 3 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/src/lib/gui/gl_2d_display.h b/src/lib/gui/gl_2d_display.h
index 1969ad25..9acb9910 100644
--- a/src/lib/gui/gl_2d_display.h
+++ b/src/lib/gui/gl_2d_display.h
@@ -33,10 +33,10 @@ class gl_2d_display
 	    {0, -1, -1, 0} // right 270
 	}};
 
-	static std::array<std::pair<GLfloat, GLfloat>, 8> computeShakePos(float dim)
+	static std::array<std::pair<GLfloat, GLfloat>, 8> computeShakePos(float src_dim, float target_dim)
 	{
-		float shake = 8.0f / dim; // 1080
-		float zero = (dim - 1000.0) / (dim*2);
+		float shake = 8.0f / target_dim;
+		float zero = (target_dim - src_dim + 3) / (target_dim*2);
 		return {{
 			{zero, zero},
 			{zero-shake, zero-shake},
@@ -50,10 +50,11 @@ class gl_2d_display
 	}
 
 public:
-	gl_2d_display(unsigned width, unsigned height)
+	gl_2d_display(unsigned src_dim, unsigned target_dim)
 	    : _p(create())
-	    , _dimension(std::min(width, height))
-	    , _shakePos(computeShakePos(_dimension))
+	    , _srcDim(src_dim)
+	    , _targetDim(target_dim)
+	    , _shakePos(computeShakePos(_srcDim, _targetDim))
 	    , _shake(_shakePos)
 	    , _rotation(ROTATIONS)
 	{
@@ -90,7 +91,7 @@ class gl_2d_display
 
 		// scaling
 		GLuint scalingUniform = glGetUniformLocation(prog, "scaling");
-		glUniform1f(scalingUniform, 2 * (1008 / _dimension));
+		glUniform1f(scalingUniform, 2 * (_srcDim / _targetDim));
 
 		// pass in rotation matrix
 		GLuint rotateUniform = glGetUniformLocation(prog, "rot");
@@ -179,7 +180,8 @@ class gl_2d_display
 	std::array<GLuint, 3> _vbo;
 	GLuint _vao;
 	unsigned _i = 0;
-	float _dimension;
+	float _srcDim;
+	float _targetDim;
 
 	std::array<std::pair<GLfloat, GLfloat>, 8> _shakePos;
 	loop_iterator<decltype(_shakePos)> _shake;
diff --git a/src/lib/gui/window_glfw.h b/src/lib/gui/window_glfw.h
index 03091224..c45d2a45 100644
--- a/src/lib/gui/window_glfw.h
+++ b/src/lib/gui/window_glfw.h
@@ -32,7 +32,7 @@ class window_glfw : public window_interface<window_glfw>
 		glfwMakeContextCurrent(_w);
 		glfwSwapInterval(1);
 
-		_display = std::make_shared<cimbar::gl_2d_display>(width, height);
+		_display = std::make_shared<cimbar::gl_2d_display>(1024, std::min(width, height));
 		glGenTextures(1, &_texid);
 		init_opengl(width, height);
 	}
diff --git a/src/wasm/cimbar_js/wasm.cpp b/src/wasm/cimbar_js/wasm.cpp
index 5c33dd96..8beb92ba 100644
--- a/src/wasm/cimbar_js/wasm.cpp
+++ b/src/wasm/cimbar_js/wasm.cpp
@@ -51,7 +51,7 @@ int render()
 	if (_fes->block_count() > required)
 	{
 		_fes->reset();
-		_window->rotate(0);
+		_window->shake(0);
 	}
 
 	SimpleEncoder enc(_ecc, cimbar::Config::symbol_bits(), _colorBits);
@@ -102,7 +102,7 @@ int configure(unsigned color_bits)
 				_fes = nullptr;
 				_window->clear();
 			}
-			_window->rotate(0);
+			_window->shake(0);
 		}
 	}
 	return 0;

From a2ffe08ccdbfae654191c28763dc661f66bc88c2 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Sat, 20 Feb 2021 01:48:21 -0600
Subject: [PATCH 07/26] maybe this instead -- variable canvas size for
 CimbWriter

It's slightly more data to copy to the GPU (1040x1040px vs
1024x1024), but everything else is much more sane...
---
 src/exe/cimbar_send/send.cpp           |  5 +--
 src/lib/cimb_translator/CimbWriter.cpp | 42 +++++++++++++++-----------
 src/lib/cimb_translator/CimbWriter.h   |  6 +++-
 src/lib/encoder/Encoder.h              |  6 ++--
 src/lib/encoder/SimpleEncoder.h        |  8 +++--
 src/lib/gui/gl_2d_display.h            | 23 +++++---------
 src/lib/gui/window_glfw.h              | 10 ++++--
 src/lib/gui/window_interface.h         |  5 +++
 src/wasm/cimbar_js/wasm.cpp            |  6 ++--
 9 files changed, 64 insertions(+), 47 deletions(-)

diff --git a/src/exe/cimbar_send/send.cpp b/src/exe/cimbar_send/send.cpp
index 7cdcf87b..7730ca7c 100644
--- a/src/exe/cimbar_send/send.cpp
+++ b/src/exe/cimbar_send/send.cpp
@@ -58,8 +58,9 @@ int main(int argc, char** argv)
 	bool dark = true;
 	bool use_rotatecam = result.count("rotatecam");
 	bool use_shakycam = result.count("shakycam");
+	int window_size = 1080;
 
-	cimbar::window w(1080, 1080, "cimbar_send");
+	cimbar::window w(window_size, window_size, "cimbar_send");
 	if (!w.is_good())
 	{
 		std::cerr << "failed to create window :(" << std::endl;
@@ -85,6 +86,6 @@ int main(int argc, char** argv)
 	Encoder en(ecc, cimbar::Config::symbol_bits(), colorBits);
 	while (running)
 		for (const string& f : infiles)
-			en.encode_fountain(f, draw, compressionLevel);
+			en.encode_fountain(f, draw, compressionLevel, 8.0, window_size);
 	return 0;
 }
diff --git a/src/lib/cimb_translator/CimbWriter.cpp b/src/lib/cimb_translator/CimbWriter.cpp
index c5f87a0b..bb021ef7 100644
--- a/src/lib/cimb_translator/CimbWriter.cpp
+++ b/src/lib/cimb_translator/CimbWriter.cpp
@@ -33,39 +33,45 @@ namespace {
 		string name = dark? "guide-vertical-dark" : "guide-vertical-light";
 		return cimbar::load_img(fmt::format("bitmap/{}.png", name));
 	}
-
-	void paste(cv::Mat& canvas, const cv::Mat& img, int x, int y)
-	{
-		img.copyTo(canvas(cv::Rect(x, y, img.cols, img.rows)));
-	}
 }
 
-CimbWriter::CimbWriter(unsigned symbol_bits, unsigned color_bits, bool dark)
+CimbWriter::CimbWriter(unsigned symbol_bits, unsigned color_bits, bool dark, int size)
     : _positions(Config::cell_spacing(), Config::num_cells(), Config::cell_size(), Config::corner_padding(), Config::interleave_blocks(), Config::interleave_partitions())
     , _encoder(symbol_bits, color_bits)
 {
-	unsigned size = cimbar::Config::image_size();
+	if (size > cimbar::Config::image_size())
+		_offset = (size - cimbar::Config::image_size()) / 2;
+	else
+		size = cimbar::Config::image_size();
 
 	cv::Scalar bgcolor = dark? cv::Scalar(0, 0, 0) : cv::Scalar(0xFF, 0xFF, 0xFF);
 	_image = cv::Mat(size, size, CV_8UC3, bgcolor);
 
+	// from here on, we only care about the internal size
+	size = cimbar::Config::image_size();
+
 	cv::Mat anchor = getAnchor(dark);
-	paste(_image, anchor, 0, 0);
-	paste(_image, anchor, 0, size - anchor.cols);
-	paste(_image, anchor, size - anchor.rows, 0);
+	paste(anchor, 0, 0);
+	paste(anchor, 0, size - anchor.cols);
+	paste(anchor, size - anchor.rows, 0);
 
 	cv::Mat secondaryAnchor = getSecondaryAnchor(dark);
-	paste(_image, secondaryAnchor, size - anchor.rows, size - anchor.cols);
+	paste(secondaryAnchor, size - anchor.rows, size - anchor.cols);
 
 	cv::Mat hg = getHorizontalGuide(dark);
-	paste(_image, hg, (size/2) - (hg.cols/2), 2);
-	paste(_image, hg, (size/2) - (hg.cols/2), size-4);
-	paste(_image, hg, (size/2) - (hg.cols/2) - hg.cols, size-4);
-	paste(_image, hg, (size/2) - (hg.cols/2) + hg.cols, size-4);
+	paste(hg, (size/2) - (hg.cols/2), 2);
+	paste(hg, (size/2) - (hg.cols/2), size-4);
+	paste(hg, (size/2) - (hg.cols/2) - hg.cols, size-4);
+	paste(hg, (size/2) - (hg.cols/2) + hg.cols, size-4);
 
 	cv::Mat vg = getVerticalGuide(dark);
-	paste(_image, vg, 2, (size/2) - (vg.rows/2));
-	paste(_image, vg, size-4, (size/2) - (vg.rows/2));
+	paste(vg, 2, (size/2) - (vg.rows/2));
+	paste(vg, size-4, (size/2) - (vg.rows/2));
+}
+
+void CimbWriter::paste(const cv::Mat& img, int x, int y)
+{
+	img.copyTo(_image(cv::Rect(x+_offset, y+_offset, img.cols, img.rows)));
 }
 
 bool CimbWriter::write(unsigned bits)
@@ -77,7 +83,7 @@ bool CimbWriter::write(unsigned bits)
 
 	CellPositions::coordinate xy = _positions.next();
 	cv::Mat cell = _encoder.encode(bits);
-	paste(_image, cell, xy.first, xy.second);
+	paste(cell, xy.first, xy.second);
 	return true;
 }
 
diff --git a/src/lib/cimb_translator/CimbWriter.h b/src/lib/cimb_translator/CimbWriter.h
index b76321f2..9af71d9c 100644
--- a/src/lib/cimb_translator/CimbWriter.h
+++ b/src/lib/cimb_translator/CimbWriter.h
@@ -7,15 +7,19 @@
 class CimbWriter
 {
 public:
-	CimbWriter(unsigned symbol_bits, unsigned color_bits, bool dark=true);
+	CimbWriter(unsigned symbol_bits, unsigned color_bits, bool dark=true, int size=0);
 
 	bool write(unsigned bits);
 	bool done() const;
 
 	cv::Mat image() const;
 
+protected:
+	void paste(const cv::Mat& img, int x, int y);
+
 protected:
 	cv::Mat _image;
 	CellPositions _positions;
 	CimbEncoder _encoder;
+	unsigned _offset = 0;
 };
diff --git a/src/lib/encoder/Encoder.h b/src/lib/encoder/Encoder.h
index a296d7f9..1ac9e8fe 100644
--- a/src/lib/encoder/Encoder.h
+++ b/src/lib/encoder/Encoder.h
@@ -16,7 +16,7 @@ class Encoder : public SimpleEncoder
 
 	unsigned encode(const std::string& filename, std::string output_prefix);
 	unsigned encode_fountain(const std::string& filename, std::string output_prefix, int compression_level=6, double redundancy=1.2);
-	unsigned encode_fountain(const std::string& filename, const std::function<bool(const cv::Mat&, unsigned)>& on_frame, int compression_level=6, double redundancy=4.0);
+	unsigned encode_fountain(const std::string& filename, const std::function<bool(const cv::Mat&, unsigned)>& on_frame, int compression_level=6, double redundancy=4.0, int canvas_size=0);
 };
 
 inline unsigned Encoder::encode(const std::string& filename, std::string output_prefix)
@@ -39,7 +39,7 @@ inline unsigned Encoder::encode(const std::string& filename, std::string output_
 	return i;
 }
 
-inline unsigned Encoder::encode_fountain(const std::string& filename, const std::function<bool(const cv::Mat&, unsigned)>& on_frame, int compression_level, double redundancy)
+inline unsigned Encoder::encode_fountain(const std::string& filename, const std::function<bool(const cv::Mat&, unsigned)>& on_frame, int compression_level, double redundancy, int canvas_size)
 {
 	std::ifstream infile(filename);
 	fountain_encoder_stream::ptr fes = create_fountain_encoder(infile, compression_level);
@@ -56,7 +56,7 @@ inline unsigned Encoder::encode_fountain(const std::string& filename, const std:
 	unsigned i = 0;
 	while (i < requiredFrames)
 	{
-		auto frame = encode_next(*fes);
+		auto frame = encode_next(*fes, canvas_size);
 		if (!frame)
 			break;
 
diff --git a/src/lib/encoder/SimpleEncoder.h b/src/lib/encoder/SimpleEncoder.h
index f3b2cb26..2139c8c8 100644
--- a/src/lib/encoder/SimpleEncoder.h
+++ b/src/lib/encoder/SimpleEncoder.h
@@ -19,7 +19,7 @@ class SimpleEncoder
 	void set_encode_id(uint8_t encode_id); // [0-127] -- the high bit is ignored.
 
 	template <typename STREAM>
-	std::optional<cv::Mat> encode_next(STREAM& stream);
+	std::optional<cv::Mat> encode_next(STREAM& stream, int canvas_size=0);
 
 	template <typename STREAM>
 	fountain_encoder_stream::ptr create_fountain_encoder(STREAM& stream, int compression_level=6);
@@ -28,6 +28,7 @@ class SimpleEncoder
 	unsigned _eccBytes;
 	unsigned _bitsPerSymbol;
 	unsigned _bitsPerColor;
+	bool _dark;
 	uint8_t _encodeId = 0;
 };
 
@@ -35,6 +36,7 @@ inline SimpleEncoder::SimpleEncoder(int ecc_bytes, unsigned bits_per_symbol, int
     : _eccBytes(ecc_bytes >= 0? ecc_bytes : cimbar::Config::ecc_bytes())
     , _bitsPerSymbol(bits_per_symbol? bits_per_symbol : cimbar::Config::symbol_bits())
     , _bitsPerColor(bits_per_color >= 0? bits_per_color : cimbar::Config::color_bits())
+    , _dark(cimbar::Config::dark())
 {
 }
 
@@ -56,13 +58,13 @@ inline void SimpleEncoder::set_encode_id(uint8_t encode_id)
  * */
 
 template <typename STREAM>
-inline std::optional<cv::Mat> SimpleEncoder::encode_next(STREAM& stream)
+inline std::optional<cv::Mat> SimpleEncoder::encode_next(STREAM& stream, int canvas_size)
 {
 	if (!stream.good())
 		return std::nullopt;
 
 	unsigned bits_per_op = _bitsPerColor + _bitsPerSymbol;
-	CimbWriter writer(_bitsPerSymbol, _bitsPerColor);
+	CimbWriter writer(_bitsPerSymbol, _bitsPerColor, _dark, canvas_size);
 
 	reed_solomon_stream rss(stream, _eccBytes);
 	bitreader br;
diff --git a/src/lib/gui/gl_2d_display.h b/src/lib/gui/gl_2d_display.h
index 9acb9910..57151ec9 100644
--- a/src/lib/gui/gl_2d_display.h
+++ b/src/lib/gui/gl_2d_display.h
@@ -33,10 +33,10 @@ class gl_2d_display
 	    {0, -1, -1, 0} // right 270
 	}};
 
-	static std::array<std::pair<GLfloat, GLfloat>, 8> computeShakePos(float src_dim, float target_dim)
+	static std::array<std::pair<GLfloat, GLfloat>, 8> computeShakePos(float dim)
 	{
-		float shake = 8.0f / target_dim;
-		float zero = (target_dim - src_dim + 3) / (target_dim*2);
+		float shake = 8.0f / dim; // 1080
+		float zero = 0.0f;
 		return {{
 			{zero, zero},
 			{zero-shake, zero-shake},
@@ -50,11 +50,10 @@ class gl_2d_display
 	}
 
 public:
-	gl_2d_display(unsigned src_dim, unsigned target_dim)
+	gl_2d_display(unsigned width, unsigned height)
 	    : _p(create())
-	    , _srcDim(src_dim)
-	    , _targetDim(target_dim)
-	    , _shakePos(computeShakePos(_srcDim, _targetDim))
+	    , _dimension(std::min(width, height))
+	    , _shakePos(computeShakePos(_dimension))
 	    , _shake(_shakePos)
 	    , _rotation(ROTATIONS)
 	{
@@ -89,10 +88,6 @@ class gl_2d_display
 		glBindTexture(GL_TEXTURE_2D, texture);
 		glUniform1i(textureUniform, 0);
 
-		// scaling
-		GLuint scalingUniform = glGetUniformLocation(prog, "scaling");
-		glUniform1f(scalingUniform, 2 * (_srcDim / _targetDim));
-
 		// pass in rotation matrix
 		GLuint rotateUniform = glGetUniformLocation(prog, "rot");
 		std::array<GLfloat, 4> rot = *_rotation;
@@ -150,14 +145,13 @@ class gl_2d_display
 		static const std::string VERTEX_SHADER_SRC = R"(#version 300 es
 		uniform mat2 rot;
 		uniform vec2 tform;
-		uniform float scaling;
 		in vec4 vert;
 		out vec2 texCoord;
 		void main() {
 		   gl_Position = vec4(vert.x, vert.y, 0.0f, 1.0f);
 		   vec2 ori = vec2(vert.x, vert.y);
 		   ori *= rot;
-		   texCoord = vec2(1.0f - ori.x, 1.0f - ori.y) / scaling;
+		   texCoord = vec2(1.0f - ori.x, 1.0f - ori.y) / 2.0;
 		   texCoord -= tform;
 		})";
 
@@ -180,8 +174,7 @@ class gl_2d_display
 	std::array<GLuint, 3> _vbo;
 	GLuint _vao;
 	unsigned _i = 0;
-	float _srcDim;
-	float _targetDim;
+	float _dimension;
 
 	std::array<std::pair<GLfloat, GLfloat>, 8> _shakePos;
 	loop_iterator<decltype(_shakePos)> _shake;
diff --git a/src/lib/gui/window_glfw.h b/src/lib/gui/window_glfw.h
index c45d2a45..64c183ae 100644
--- a/src/lib/gui/window_glfw.h
+++ b/src/lib/gui/window_glfw.h
@@ -16,6 +16,7 @@ class window_glfw : public window_interface<window_glfw>
 {
 public:
 	window_glfw(unsigned width, unsigned height, std::string title)
+	    : _width(width)
 	{
 		if (!glfwInit())
 		{
@@ -32,7 +33,7 @@ class window_glfw : public window_interface<window_glfw>
 		glfwMakeContextCurrent(_w);
 		glfwSwapInterval(1);
 
-		_display = std::make_shared<cimbar::gl_2d_display>(1024, std::min(width, height));
+		_display = std::make_shared<cimbar::gl_2d_display>(width, height);
 		glGenTextures(1, &_texid);
 		init_opengl(width, height);
 	}
@@ -95,6 +96,11 @@ class window_glfw : public window_interface<window_glfw>
 			std::this_thread::sleep_for(std::chrono::milliseconds(delay-millis));
 	}
 
+	unsigned width() const
+	{
+		return _width;
+	}
+
 protected:
 	void init_opengl(int width, int height)
 	{
@@ -117,8 +123,8 @@ class window_glfw : public window_interface<window_glfw>
 	GLFWwindow* _w;
 	GLuint _texid;
 	std::shared_ptr<cimbar::gl_2d_display> _display;
+	unsigned _width;
 	bool _good = true;
 };
 
 }
-
diff --git a/src/lib/gui/window_interface.h b/src/lib/gui/window_interface.h
index 1728626a..d61fc4ab 100644
--- a/src/lib/gui/window_interface.h
+++ b/src/lib/gui/window_interface.h
@@ -27,6 +27,11 @@ struct window_interface
 	{
 		static_cast<T*>(this)->show(img, delay);
 	}
+
+	unsigned width() const
+	{
+		return static_cast<T*>(this)->width();
+	}
 };
 
 }
diff --git a/src/wasm/cimbar_js/wasm.cpp b/src/wasm/cimbar_js/wasm.cpp
index 8beb92ba..9529aad8 100644
--- a/src/wasm/cimbar_js/wasm.cpp
+++ b/src/wasm/cimbar_js/wasm.cpp
@@ -44,10 +44,10 @@ int render()
 	if (!_window or !_fes)
 		return 0;
 
-	// we generate 2x the amount of required blocks -- unless everything fits in a single frame.
+	// we generate 8x the amount of required blocks -- unless everything fits in a single frame.
 	unsigned required = _fes->blocks_required();
 	if (required > cimbar::Config::fountain_chunks_per_frame())
-		required = required*4;
+		required = required*8;
 	if (_fes->block_count() > required)
 	{
 		_fes->reset();
@@ -57,7 +57,7 @@ int render()
 	SimpleEncoder enc(_ecc, cimbar::Config::symbol_bits(), _colorBits);
 	enc.set_encode_id(_encodeId);
 
-	std::optional<cv::Mat> img = enc.encode_next(*_fes);
+	std::optional<cv::Mat> img = enc.encode_next(*_fes, _window->width());
 	if (!img)
 	{
 		std::cerr << "no image :(" << std::endl;

From 87338c47d7277c8a46a11f6e9334b1edc7e9f7b4 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Mon, 1 Mar 2021 22:28:37 -0600
Subject: [PATCH 08/26] Reimplement shakycam for opencv_highgui

I kinda want to leave rotate as not implemented? Maybe I'll add a todo
---
 src/lib/gui/shaky_cam.h        | 13 +++++++++----
 src/lib/gui/window_cvhighgui.h | 18 +++++++++++++++---
 2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/src/lib/gui/shaky_cam.h b/src/lib/gui/shaky_cam.h
index 61847234..10a0be5c 100644
--- a/src/lib/gui/shaky_cam.h
+++ b/src/lib/gui/shaky_cam.h
@@ -10,13 +10,13 @@ class shaky_cam
 {
 public:
 	static constexpr std::array<std::pair<int, int>, 8> SHAKE_POS = {{
-		{0, 0}, {-8, -8}, {0, 0}, {8, 8}, {0, 0}, {-8, 8}, {0, 0}, {8, -8}
+	    {0, 0}, {-8, -8}, {0, 0}, {8, 8}, {0, 0}, {-8, 8}, {0, 0}, {8, -8}
 	}};
 
 public:
 	shaky_cam(unsigned img_size, unsigned w, unsigned h, bool dark)
-		: _shakycam(true)
-		, _shakePos(SHAKE_POS)
+	    : _shakycam(true)
+	    , _shakePos(SHAKE_POS)
 	{
 		unsigned minFrameSize = img_size + 16;
 		w = std::max(w, minFrameSize);
@@ -45,6 +45,12 @@ class shaky_cam
 		_shakePos.reset();
 	}
 
+	void shake()
+	{
+		if (_shakycam)
+			++_shakePos;
+	}
+
 	cv::Mat& draw(const cv::Mat& img)
 	{
 		_frame = _bgcolor;
@@ -59,7 +65,6 @@ class shaky_cam
 				offsetX += (*_shakePos).first;
 				offsetY += (*_shakePos).second;
 			}
-			++_shakePos;
 		}
 
 		img.copyTo(_frame(cv::Rect(offsetX, offsetY, img.cols, img.rows)));
diff --git a/src/lib/gui/window_cvhighgui.h b/src/lib/gui/window_cvhighgui.h
index e5be7e35..bf8db4a4 100644
--- a/src/lib/gui/window_cvhighgui.h
+++ b/src/lib/gui/window_cvhighgui.h
@@ -3,12 +3,16 @@
 
 #include "window_interface.h"
 
+#include "shaky_cam.h"
+
 namespace cimbar {
 
 class window_cvhighgui : public window_interface<window_cvhighgui>
 {
 public:
-	window_cvhighgui(unsigned, unsigned, std::string)
+	window_cvhighgui(unsigned width, unsigned height, std::string title)
+	    : _cam(std::min(width, height), width, height, true)
+	    , _title(title)
 	{}
 
 	bool is_good() const
@@ -18,20 +22,28 @@ class window_cvhighgui : public window_interface<window_cvhighgui>
 
 	bool should_close() const
 	{
-		return cv::getWindowProperty("image", cv::WND_PROP_AUTOSIZE) < 0;
+		return cv::getWindowProperty(_title, cv::WND_PROP_AUTOSIZE) < 0;
 	}
 
 	void rotate(unsigned i=1)
 	{
 	}
 
+	void shake(unsigned i=1)
+	{
+		if (i > 0)
+			_cam.shake();
+	}
+
 	void show(const cv::Mat& img, unsigned delay)
 	{
-		cv::imshow("image", img);
+		cv::imshow(_title, _cam.draw(img));
 		cv::waitKey(delay); // functions as the frame delay... you can hold down a key to make it go faster
 	}
 
 protected:
+	cimbar::shaky_cam _cam;
+	std::string _title;
 };
 
 }

From a49fe7f2e2647c70509edf94224bb0fa5d2b0089 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Mon, 1 Mar 2021 22:30:10 -0600
Subject: [PATCH 09/26] Only dark mode for now

---
 src/exe/cimbar_send/send.cpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/exe/cimbar_send/send.cpp b/src/exe/cimbar_send/send.cpp
index 7730ca7c..a65e12ae 100644
--- a/src/exe/cimbar_send/send.cpp
+++ b/src/exe/cimbar_send/send.cpp
@@ -55,7 +55,6 @@ int main(int argc, char** argv)
 		fps = defaultFps;
 	unsigned delay = 1000 / fps;
 
-	bool dark = true;
 	bool use_rotatecam = result.count("rotatecam");
 	bool use_shakycam = result.count("shakycam");
 	int window_size = 1080;

From c15ac29ddedc34fc334fa8ae89822b85080de3c8 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Tue, 2 Mar 2021 20:52:13 -0600
Subject: [PATCH 10/26] The motivation of the shaky_cam is to detect
 cross-frame overlap,

... not an interpretive barcode dance.

Less snarkily, I'm trying to find the right balance between "decoder can
discard bad frames" and "user gets a headache looking at the barcode".
---
 src/lib/gui/gl_2d_display.h | 10 +++-------
 src/lib/gui/shaky_cam.h     |  4 ++--
 2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/src/lib/gui/gl_2d_display.h b/src/lib/gui/gl_2d_display.h
index 57151ec9..1d80400a 100644
--- a/src/lib/gui/gl_2d_display.h
+++ b/src/lib/gui/gl_2d_display.h
@@ -33,7 +33,7 @@ class gl_2d_display
 	    {0, -1, -1, 0} // right 270
 	}};
 
-	static std::array<std::pair<GLfloat, GLfloat>, 8> computeShakePos(float dim)
+	static std::array<std::pair<GLfloat, GLfloat>, 4> computeShakePos(float dim)
 	{
 		float shake = 8.0f / dim; // 1080
 		float zero = 0.0f;
@@ -41,11 +41,7 @@ class gl_2d_display
 			{zero, zero},
 			{zero-shake, zero-shake},
 			{zero, zero},
-			{zero+shake, zero+shake},
-			{zero, zero},
-			{zero-shake, zero+shake},
-			{zero, zero},
-			{zero+shake, zero-shake}
+			{zero+shake, zero+shake}
 		}};
 	}
 
@@ -176,7 +172,7 @@ class gl_2d_display
 	unsigned _i = 0;
 	float _dimension;
 
-	std::array<std::pair<GLfloat, GLfloat>, 8> _shakePos;
+	std::array<std::pair<GLfloat, GLfloat>, 4> _shakePos;
 	loop_iterator<decltype(_shakePos)> _shake;
 	loop_iterator<decltype(ROTATIONS)> _rotation;
 };
diff --git a/src/lib/gui/shaky_cam.h b/src/lib/gui/shaky_cam.h
index 10a0be5c..4101b5ea 100644
--- a/src/lib/gui/shaky_cam.h
+++ b/src/lib/gui/shaky_cam.h
@@ -9,8 +9,8 @@ namespace cimbar {
 class shaky_cam
 {
 public:
-	static constexpr std::array<std::pair<int, int>, 8> SHAKE_POS = {{
-	    {0, 0}, {-8, -8}, {0, 0}, {8, 8}, {0, 0}, {-8, 8}, {0, 0}, {8, -8}
+	static constexpr std::array<std::pair<int, int>, 4> SHAKE_POS = {{
+	    {0, 0}, {-8, -8}, {0, 0}, {8, 8}
 	}};
 
 public:

From 6933d3e0a6a0af64c1a85ca559a4d0dfb8e7aef1 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Tue, 2 Mar 2021 20:59:51 -0600
Subject: [PATCH 11/26] fix color bug with highgui

It'd be nice to have a test to catch this :thinking:
---
 src/lib/gui/shaky_cam.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/lib/gui/shaky_cam.h b/src/lib/gui/shaky_cam.h
index 4101b5ea..69ab785c 100644
--- a/src/lib/gui/shaky_cam.h
+++ b/src/lib/gui/shaky_cam.h
@@ -68,6 +68,7 @@ class shaky_cam
 		}
 
 		img.copyTo(_frame(cv::Rect(offsetX, offsetY, img.cols, img.rows)));
+		cv::cvtColor(_frame, _frame, cv::COLOR_BGR2RGB);
 		return _frame;
 	}
 

From 21e39dbada3af55b59095d29e599f220d776cb80 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Tue, 2 Mar 2021 21:02:47 -0600
Subject: [PATCH 12/26] Update help

---
 src/exe/cimbar/cimbar.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/exe/cimbar/cimbar.cpp b/src/exe/cimbar/cimbar.cpp
index 1990a60e..8f8c91e1 100644
--- a/src/exe/cimbar/cimbar.cpp
+++ b/src/exe/cimbar/cimbar.cpp
@@ -74,7 +74,7 @@ int main(int argc, char** argv)
 	unsigned ecc = cimbar::Config::ecc_bytes();
 	options.add_options()
 	    ("i,in", "Encoded pngs/jpgs/etc (for decode), or file to encode", cxxopts::value<vector<string>>())
-	    ("o,out", "Output file or directory.", cxxopts::value<string>())
+	    ("o,out", "Output file prefix (encoding) or directory (decoding).", cxxopts::value<string>())
 	    ("c,color-bits", "Color bits. [0-3]", cxxopts::value<int>()->default_value(turbo::str::str(colorBits)))
 	    ("e,ecc", "ECC level", cxxopts::value<unsigned>()->default_value(turbo::str::str(ecc)))
 	    ("f,fountain", "Attempt fountain encode/decode", cxxopts::value<bool>())

From 0626afca7dc3443684c909f4a20477e4ebd79b14 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Wed, 3 Mar 2021 20:19:14 -0600
Subject: [PATCH 13/26] Tired of the mouse cursor getting in the way...

---
 web/index.html | 3 +++
 web/main.js    | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/web/index.html b/web/index.html
index f7e14d16..599d93b8 100644
--- a/web/index.html
+++ b/web/index.html
@@ -57,6 +57,9 @@
 	opacity: 0;
 	pointer-events: auto;
 }
+#invisible_click.active {
+	cursor: none;
+}
 #nav-container:focus-within + #invisible_click {
 	pointer-events: none;
 	display: none;
diff --git a/web/main.js b/web/main.js
index 6f7894d1..d620b21c 100644
--- a/web/main.js
+++ b/web/main.js
@@ -68,6 +68,7 @@ return {
     var res = Module._encode(data.byteOffset, data.length);
     console.log(res);
     Main.setTitle(filename);
+    Main.setActive(true);
   },
 
   dragDrop : function(event)
@@ -121,6 +122,14 @@ return {
     }
   },
 
+  setActive : function(active)
+  {
+    // hide cursor when there's a barcode active
+    var invisi = document.getElementById("invisible_click");
+    invisi.classList.remove("active");
+    invisi.classList.add("active");
+  },
+
   setColorBits : function(color_bits)
   {
     Module._configure(color_bits);

From f979012d38e02db64071471fd862f966acd707b1 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Wed, 3 Mar 2021 21:13:55 -0600
Subject: [PATCH 14/26] :thinking:

---
 src/wasm/cimbar_js/wasm.cpp | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/src/wasm/cimbar_js/wasm.cpp b/src/wasm/cimbar_js/wasm.cpp
index 9529aad8..f9eddb2e 100644
--- a/src/wasm/cimbar_js/wasm.cpp
+++ b/src/wasm/cimbar_js/wasm.cpp
@@ -15,6 +15,8 @@
 namespace {
 	std::shared_ptr<cimbar::window_glfw> _window;
 	std::shared_ptr<fountain_encoder_stream> _fes;
+	std::optional<cv::Mat> _next;
+
 	int _renders = 0;
 	uint8_t _encodeId = 0;
 
@@ -44,6 +46,13 @@ int render()
 	if (!_window or !_fes)
 		return 0;
 
+	// render frame first to minimize frame pacing issues
+	if (_next)
+	{
+		_window->show(*_next, 0);
+		_window->shake();
+	}
+
 	// we generate 8x the amount of required blocks -- unless everything fits in a single frame.
 	unsigned required = _fes->blocks_required();
 	if (required > cimbar::Config::fountain_chunks_per_frame())
@@ -57,15 +66,7 @@ int render()
 	SimpleEncoder enc(_ecc, cimbar::Config::symbol_bits(), _colorBits);
 	enc.set_encode_id(_encodeId);
 
-	std::optional<cv::Mat> img = enc.encode_next(*_fes, _window->width());
-	if (!img)
-	{
-		std::cerr << "no image :(" << std::endl;
-		return 0;
-	}
-
-	_window->show(*img, 0);
-	_window->shake();
+	_next = enc.encode_next(*_fes, _window->width());
 	return ++_renders;
 }
 
@@ -84,6 +85,8 @@ int encode(uint8_t* buffer, size_t size)
 
 	if (!_fes)
 		return 0;
+
+	_next.reset();
 	return 1;
 }
 
@@ -101,6 +104,7 @@ int configure(unsigned color_bits)
 				// if the data is too small, we should throw out _fes -- and clear the canvas.
 				_fes = nullptr;
 				_window->clear();
+				_next.reset();
 			}
 			_window->shake(0);
 		}

From 4c5f8266c146489c16adbc1de63fe68cc27f72d9 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Wed, 3 Mar 2021 21:31:17 -0600
Subject: [PATCH 15/26] I like this interface slightly more.

The idea here is to improve frame pacing.
---
 src/wasm/cimbar_js/CMakeLists.txt |  2 +-
 src/wasm/cimbar_js/wasm.cpp       | 12 ++++++++++--
 web/main.js                       |  5 +++--
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/src/wasm/cimbar_js/CMakeLists.txt b/src/wasm/cimbar_js/CMakeLists.txt
index 42dead63..b1746cbf 100644
--- a/src/wasm/cimbar_js/CMakeLists.txt
+++ b/src/wasm/cimbar_js/CMakeLists.txt
@@ -47,7 +47,7 @@ set (LINK_WASM_LIST
 	-s USE_GLFW=3
 	-s FILESYSTEM=0
 	-s TOTAL_MEMORY=134217728
-	-s EXPORTED_FUNCTIONS='["_render","_initialize_GL","_encode","_configure"]'
+	-s EXPORTED_FUNCTIONS='["_render","_next_frame","_initialize_GL","_encode","_configure"]'
 )
 string(REPLACE ";" " " LINK_WASM_FLAGS "${LINK_WASM_LIST}")
 
diff --git a/src/wasm/cimbar_js/wasm.cpp b/src/wasm/cimbar_js/wasm.cpp
index f9eddb2e..d8179a1b 100644
--- a/src/wasm/cimbar_js/wasm.cpp
+++ b/src/wasm/cimbar_js/wasm.cpp
@@ -17,7 +17,7 @@ namespace {
 	std::shared_ptr<fountain_encoder_stream> _fes;
 	std::optional<cv::Mat> _next;
 
-	int _renders = 0;
+	int _numFrames = 0;
 	uint8_t _encodeId = 0;
 
 	// settings
@@ -51,7 +51,15 @@ int render()
 	{
 		_window->show(*_next, 0);
 		_window->shake();
+		return 1;
 	}
+	return 0;
+}
+
+int next_frame()
+{
+	if (!_window or !_fes)
+		return 0;
 
 	// we generate 8x the amount of required blocks -- unless everything fits in a single frame.
 	unsigned required = _fes->blocks_required();
@@ -67,7 +75,7 @@ int render()
 	enc.set_encode_id(_encodeId);
 
 	_next = enc.encode_next(*_fes, _window->width());
-	return ++_renders;
+	return ++_numFrames;
 }
 
 int encode(uint8_t* buffer, size_t size)
diff --git a/web/main.js b/web/main.js
index d620b21c..e4f0b6e8 100644
--- a/web/main.js
+++ b/web/main.js
@@ -110,7 +110,8 @@ return {
   nextFrame : function()
   {
     var start = performance.now();
-    var renderCount = Module._render();
+    Module._render();
+    var frameCount = Module._next_frame();
 
     var elapsed = performance.now() - start;
     var nextInterval = _interval>elapsed? _interval-elapsed : 0;
@@ -118,7 +119,7 @@ return {
 
     if (_showStats && renderCount) {
       _renderTime += elapsed;
-      Main.setHTML( "status", elapsed + " : " + renderCount + " : " + Math.ceil(_renderTime/renderCount));
+      Main.setHTML( "status", elapsed + " : " + frameCount + " : " + Math.ceil(_renderTime/frameCount));
     }
   },
 

From 5b86c29a881111093835eecf93166ef0fafc1b65 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Wed, 3 Mar 2021 22:22:52 -0600
Subject: [PATCH 16/26] WIP: having more light (white) helps the camera

= cleaner frames = better transfer rates.

Checking in a cool gradient, because I can't resist
---
 web/index.html | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/web/index.html b/web/index.html
index 599d93b8..e8596887 100644
--- a/web/index.html
+++ b/web/index.html
@@ -14,7 +14,8 @@
 }
 
 body {
-	background-color: black;
+	background-color: white;
+	background-image: linear-gradient(187deg, rgba(16,16,16, 0.07) 0%, rgba(16,16,16, 0.07) 50%,rgba(246,239,239, 0.07) 50%, rgba(246,239,239, 0.07) 100%),linear-gradient(255deg, rgba(255,255,255, 0.09) 0%, rgba(255,255,255, 0.09) 50%,rgba(209,186,186, 0.09) 50%, rgba(209,186,186, 0.09) 100%),linear-gradient(191deg, rgba(170,156,156, 0.08) 0%, rgba(170,156,156, 0.08) 50%,rgba(255,255,255, 0.08) 50%, rgba(255,255,255, 0.08) 100%),linear-gradient(339deg, rgba(255,255,255, 0.04) 0%, rgba(255,255,255, 0.04) 50%,rgba(76,189,219, 0.04) 50%, rgba(76,189,219, 0.04) 100%),linear-gradient(173deg, rgba(125,119,119, 0.09) 0%, rgba(125,119,119, 0.09) 50%,rgba(250,246,246, 0.09) 50%, rgba(250,246,246, 0.09) 100%),linear-gradient(317deg, rgba(255,255,255, 0.01) 0%, rgba(255,255,255, 0.01) 50%,rgba(249,249,249, 0.01) 50%, rgba(249,249,249, 0.01) 100%),linear-gradient(173deg, rgba(138,123,123, 0.07) 0%, rgba(138,123,123, 0.07) 50%,rgba(251,251,251, 0.07) 50%, rgba(251,251,251, 0.07) 100%),linear-gradient(222deg, rgba(243,243,243, 0.05) 0%, rgba(243,243,243, 0.05) 50%,rgba(35,31,31, 0.05) 50%, rgba(35,31,31, 0.05) 100%),linear-gradient(232deg, rgba(251,246,246, 0.01) 0%, rgba(251,246,246, 0.01) 50%,rgba(249,249,249, 0.01) 50%, rgba(249,249,249, 0.01) 100%),linear-gradient(90deg, rgb(0,0,0),rgb(255,255,255),rgb(255,255,255));
 	color: gray;
 	height: 100vh;
 	display: grid;
@@ -39,6 +40,7 @@
 	margin: 0 auto;
 	z-index: -1;
 	color: #F0F0F0;
+	outline: 10px solid black;
 }
 
 #dragdrop::before {
@@ -113,6 +115,7 @@
   pointer-events: auto;
   touch-action: manipulation;
   outline: 0;
+  background-image: linear-gradient(180deg, rgb(0,0,0,0) 20%, rgb(0,0,0) 40%, rgb(0,0,0) 60%, rgb(0,0,0,0) 80%);
 }
 .icon-bar {
   display: block;
@@ -276,7 +279,7 @@
       </ul>
     </div>
 </div>
-<a id="invisible_click" href="javascript:void(0)" onclick="Main.clickNav()"></a>
+<a id="invisible_click" href="javascript:;" onclick="Main.clickNav()"></a>
 
 <script type="text/javascript">
 	// reset zoom

From a865dd4597a4933963880f572d878b4d6a1e6c8c Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Wed, 3 Mar 2021 23:24:56 -0600
Subject: [PATCH 17/26] Simpler gradient, same effect

---
 web/index.html | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/web/index.html b/web/index.html
index e8596887..68dd38d4 100644
--- a/web/index.html
+++ b/web/index.html
@@ -15,7 +15,7 @@
 
 body {
 	background-color: white;
-	background-image: linear-gradient(187deg, rgba(16,16,16, 0.07) 0%, rgba(16,16,16, 0.07) 50%,rgba(246,239,239, 0.07) 50%, rgba(246,239,239, 0.07) 100%),linear-gradient(255deg, rgba(255,255,255, 0.09) 0%, rgba(255,255,255, 0.09) 50%,rgba(209,186,186, 0.09) 50%, rgba(209,186,186, 0.09) 100%),linear-gradient(191deg, rgba(170,156,156, 0.08) 0%, rgba(170,156,156, 0.08) 50%,rgba(255,255,255, 0.08) 50%, rgba(255,255,255, 0.08) 100%),linear-gradient(339deg, rgba(255,255,255, 0.04) 0%, rgba(255,255,255, 0.04) 50%,rgba(76,189,219, 0.04) 50%, rgba(76,189,219, 0.04) 100%),linear-gradient(173deg, rgba(125,119,119, 0.09) 0%, rgba(125,119,119, 0.09) 50%,rgba(250,246,246, 0.09) 50%, rgba(250,246,246, 0.09) 100%),linear-gradient(317deg, rgba(255,255,255, 0.01) 0%, rgba(255,255,255, 0.01) 50%,rgba(249,249,249, 0.01) 50%, rgba(249,249,249, 0.01) 100%),linear-gradient(173deg, rgba(138,123,123, 0.07) 0%, rgba(138,123,123, 0.07) 50%,rgba(251,251,251, 0.07) 50%, rgba(251,251,251, 0.07) 100%),linear-gradient(222deg, rgba(243,243,243, 0.05) 0%, rgba(243,243,243, 0.05) 50%,rgba(35,31,31, 0.05) 50%, rgba(35,31,31, 0.05) 100%),linear-gradient(232deg, rgba(251,246,246, 0.01) 0%, rgba(251,246,246, 0.01) 50%,rgba(249,249,249, 0.01) 50%, rgba(249,249,249, 0.01) 100%),linear-gradient(90deg, rgb(0,0,0),rgb(255,255,255),rgb(255,255,255));
+	background-image: radial-gradient(circle at top left, rgb(7,0,0),rgb(244,244,244),rgb(255,255,255));
 	color: gray;
 	height: 100vh;
 	display: grid;
@@ -115,7 +115,7 @@
   pointer-events: auto;
   touch-action: manipulation;
   outline: 0;
-  background-image: linear-gradient(180deg, rgb(0,0,0,0) 20%, rgb(0,0,0) 40%, rgb(0,0,0) 60%, rgb(0,0,0,0) 80%);
+  background-image: linear-gradient(180deg, rgb(0,0,0,0) 10%, rgb(0,0,0) 40%, rgb(0,0,0) 60%, rgb(0,0,0,0) 90%);
 }
 .icon-bar {
   display: block;

From e340559746100ebe57c32167237fbb4aaf469beb Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Thu, 4 Mar 2021 00:27:06 -0600
Subject: [PATCH 18/26] New numbers, and they are quick

8-color probably needs higher ECC... :thinking:
---
 PERFORMANCE.md | 18 +++++++++++-------
 TODO.md        |  5 +++--
 web/index.html |  2 +-
 3 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/PERFORMANCE.md b/PERFORMANCE.md
index e2a4d29b..bc9d1c23 100644
--- a/PERFORMANCE.md
+++ b/PERFORMANCE.md
@@ -9,22 +9,26 @@
 	* There are 4 or 8 possible colors, encoding an additional 2-3 bits per tile.
 	* These 6-7 bits per tile work out to a maximum of 9300-10850 bytes per barcode, though in practice this number is reduced by error correction.
 	* The default ecc setting is 30/155, which is how we go from 9300 -> 7500 bytes of real data for a 4-color cimbar image.
-		* Reed Solomon is not an ideal for this use case -- specifically, it corrects byte errors, and cimbar errors tend to involve 1-3 bits at a time. However, since Reed Solomon implementations are ubiquitous, I used it for this prototype.
+		* Reed Solomon is not perfect for this use case -- specifically, it corrects byte errors, and cimbar errors tend to involve 1-3 bits at a time. However, since Reed Solomon implementations are ubiquitous, it is currently in use.
 
 ## Current sustained benchmark
 
 * 4-color cimbar with ecc=30:
-	* 2,980,556 bytes (after compression) in 36s -> 662 kilobits/s (~82 KB/s)
+	* 2,980,556 bytes (after compression) in 31s -> 769 kilobits/s (~96 KB/s)
 
 * 8-color cimbar with ecc=30:
-	* 2,980,556 bytes in 31s -> 769 kilobits/s (~96 KB/s)
+	* 2,980,556 bytes in 29s -> 822 kilobits/s (~102 KB/s)
 
 * details:
-	* these numbers are use https://github.com/sz3/cfc, running with 4 CPU threads on a Qualcomm Snapdragon 625
+	* these numbers are using https://github.com/sz3/cfc, running with 4 CPU threads on a Qualcomm Snapdragon 625
 		* perhaps I will buy a new cell phone to inflate the benchmark numbers.
-	* the sender commandline is `./cimbar_send /path/to/file -s`
-		* the `shakycam` option allows cfc to quickly discard ghosted frames, and spend more time decoding real data.
+	* the sender is the cimbar.org wasm implementation. An equivalent command line is `./cimbar_send /path/to/file -s`
+		* cimbar.org uses the `shakycam` option to allow the receiver to detect/discard "in between" frames as part of the scan step. This allows it to spend more processing time decoding real data.
 	* burst rate can be higher (or lower)
 		* to this end, lower ecc settings *can* provide better burst rates
-	* 8-color cimbar is considerably more sensitive to lighting conditions. Notably, decoding has some issues with dim screens.
+	* 8-color cimbar is considerably more sensitive to lighting conditions and color tints. When in doubt, fall back to 4-color.
 
+* other notes:
+		* having better lighting in the frame often leads to better results -- this is why cimbar.org has a (mostly) white background. cfc uses android's auto-exposure, auto-focus, etc (it's a very simple app). So good ambient light -- or a white background -- can lead to more consitent quality frame capture.
+		* cfc currently has a low resolution, so the cimbar frame should take up as much of the display as possible (trust the guide brackets)
+		* similarly, it's best to keep the camera angle as straight-on as possible, to decode the whole image successfully. Decodes should still happen at higher angles, but the "smaller" part of the image may have more errors than the error correction can deal with.
diff --git a/TODO.md b/TODO.md
index 306a45d3..8969ff0f 100644
--- a/TODO.md
+++ b/TODO.md
@@ -31,9 +31,10 @@ Performance optimizations aside, there are a number of paths that might be inter
 	* a smaller grid would be less information dense, but more resilient to errors. Probably.
 * optimal grid shape?
 	* it's a square because QR codes are square. That's it. Should it be?
+	* I'm strongly considering 4:3 for the next revision
 * more efficient ECC?
-	* LDPC?
-	* Reed Solomon operates on bytes. Most decode errors tend to average out at 1-3 bits. It's not a total disaster, because it works. However, it would be nice to have denser error correction codes.
+	* QC-LDPC?
+	* Reed Solomon operates on bytes. Most decode errors tend to average out at 1-3 bits. In the pathological case, such a bit error will span two bytes. It's not a total disaster, because it works. However, it would be nice to use state of the art ECC.
 * proper GPU support (OpenCV + openCL) on android?
 * ???
 	* still reading? Of course there's more! There's always more!
diff --git a/web/index.html b/web/index.html
index 68dd38d4..ace52819 100644
--- a/web/index.html
+++ b/web/index.html
@@ -40,7 +40,7 @@
 	margin: 0 auto;
 	z-index: -1;
 	color: #F0F0F0;
-	outline: 10px solid black;
+	outline: 8px solid black;
 }
 
 #dragdrop::before {

From 48b2d1a19fea4fadf36e0e9b7130072db7c072ea Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Thu, 4 Mar 2021 01:02:32 -0600
Subject: [PATCH 19/26] Spending my time on important things, like gradients

---
 web/index.html | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/web/index.html b/web/index.html
index ace52819..c3eb8fd9 100644
--- a/web/index.html
+++ b/web/index.html
@@ -40,7 +40,8 @@
 	margin: 0 auto;
 	z-index: -1;
 	color: #F0F0F0;
-	outline: 8px solid black;
+	outline: 6px solid black;
+	box-shadow: 0px 0px 12px black, 0px 0px 18px black;
 }
 
 #dragdrop::before {

From 724733974aa15bd063e327c3376f1bf15b0a1d69 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Thu, 4 Mar 2021 02:47:02 -0600
Subject: [PATCH 20/26] Fullscreen toggle?

---
 web/index.html |  1 +
 web/main.js    | 16 ++++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/web/index.html b/web/index.html
index c3eb8fd9..98d11f18 100644
--- a/web/index.html
+++ b/web/index.html
@@ -272,6 +272,7 @@
       <span id="current-file">No file selected</span>
       <ul>
         <li><a class="attention" id="nav-find-file-link" href="javascript:void(0)" onclick="Main.clickFileInput()">Find File</a></li>
+        <li><a href="javascript:void(0)" onclick="Main.toggleFullscreen()">Fullscreen</a></li>
         <hr>
         <li><a class="c4" href="javascript:void(0)" onclick="Main.setColorBits(2)">4-color</a></li>
         <li><a class="c8" href="javascript:void(0)" onclick="Main.setColorBits(3)">8-color</a></li>
diff --git a/web/main.js b/web/main.js
index e4f0b6e8..a3388d98 100644
--- a/web/main.js
+++ b/web/main.js
@@ -6,6 +6,17 @@ var _showStats = false;
 var _renders = 0;
 var _renderTime = 0;
 
+function toggleFullscreen()
+{
+  var elem = document.body;
+  if (document.fullscreenElement) {
+    document.exitFullscreen();
+  }
+  else {
+    elem.requestFullscreen();
+  }
+}
+
 function importFile(f)
 {
   const fileReader = new FileReader();
@@ -38,6 +49,11 @@ return {
     Main.alignInvisibleClick(canvas);
   },
 
+  toggleFullscreen : function()
+  {
+    toggleFullscreen();
+  },
+
   scaleCanvas : function(canvas, width, height)
   {
     var dim = width;

From f8408b312231bd53054b7b5ae0daa9b347c91f14 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Thu, 4 Mar 2021 18:17:20 -0600
Subject: [PATCH 21/26] I think document.documentElement is what I actually
 want

---
 web/main.js | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/web/main.js b/web/main.js
index a3388d98..bf74e8bc 100644
--- a/web/main.js
+++ b/web/main.js
@@ -8,12 +8,11 @@ var _renderTime = 0;
 
 function toggleFullscreen()
 {
-  var elem = document.body;
   if (document.fullscreenElement) {
     document.exitFullscreen();
   }
   else {
-    elem.requestFullscreen();
+    document.documentElement.requestFullscreen();
   }
 }
 

From bf2c4928f14fdbdc8ca5b82a4f7c3dbae5f3620a Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Thu, 4 Mar 2021 18:44:58 -0600
Subject: [PATCH 22/26] Misc code cleanup

---
 src/lib/gui/gl_2d_display.h    | 6 +-----
 src/lib/gui/window_interface.h | 5 -----
 src/wasm/cimbar_js/wasm.cpp    | 4 +++-
 3 files changed, 4 insertions(+), 11 deletions(-)

diff --git a/src/lib/gui/gl_2d_display.h b/src/lib/gui/gl_2d_display.h
index 1d80400a..becd9fc3 100644
--- a/src/lib/gui/gl_2d_display.h
+++ b/src/lib/gui/gl_2d_display.h
@@ -7,8 +7,6 @@
 
 #include <GLES3/gl3.h>
 #include <GLES2/gl2ext.h>
-
-#include <iostream>
 #include <memory>
 
 namespace cimbar {
@@ -48,8 +46,7 @@ class gl_2d_display
 public:
 	gl_2d_display(unsigned width, unsigned height)
 	    : _p(create())
-	    , _dimension(std::min(width, height))
-	    , _shakePos(computeShakePos(_dimension))
+	    , _shakePos(computeShakePos(std::min(width, height)))
 	    , _shake(_shakePos)
 	    , _rotation(ROTATIONS)
 	{
@@ -170,7 +167,6 @@ class gl_2d_display
 	std::array<GLuint, 3> _vbo;
 	GLuint _vao;
 	unsigned _i = 0;
-	float _dimension;
 
 	std::array<std::pair<GLfloat, GLfloat>, 4> _shakePos;
 	loop_iterator<decltype(_shakePos)> _shake;
diff --git a/src/lib/gui/window_interface.h b/src/lib/gui/window_interface.h
index d61fc4ab..1728626a 100644
--- a/src/lib/gui/window_interface.h
+++ b/src/lib/gui/window_interface.h
@@ -27,11 +27,6 @@ struct window_interface
 	{
 		static_cast<T*>(this)->show(img, delay);
 	}
-
-	unsigned width() const
-	{
-		return static_cast<T*>(this)->width();
-	}
 };
 
 }
diff --git a/src/wasm/cimbar_js/wasm.cpp b/src/wasm/cimbar_js/wasm.cpp
index d8179a1b..2bd7b93c 100644
--- a/src/wasm/cimbar_js/wasm.cpp
+++ b/src/wasm/cimbar_js/wasm.cpp
@@ -41,12 +41,14 @@ int initialize_GL(int width, int height)
 	return 1;
 }
 
+// render() and next_frame() could be put in the same function,
+// but it seems cleaner to split them.
+// in any case, we're concerned with frame pacing (some encodes take longer than others)
 int render()
 {
 	if (!_window or !_fes)
 		return 0;
 
-	// render frame first to minimize frame pacing issues
 	if (_next)
 	{
 		_window->show(*_next, 0);

From 206c7868eedf2280ea28a63993dddef464af53d7 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Thu, 4 Mar 2021 21:17:06 -0600
Subject: [PATCH 23/26] Add a few tests for the larger size

---
 .../cimb_translator/test/CimbWriterTest.cpp   | 18 +++++++++++++
 src/lib/encoder/Encoder.h                     |  6 ++---
 src/lib/encoder/test/EncoderTest.cpp          | 25 +++++++++++++++----
 3 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/src/lib/cimb_translator/test/CimbWriterTest.cpp b/src/lib/cimb_translator/test/CimbWriterTest.cpp
index 35d64b46..0e047d96 100644
--- a/src/lib/cimb_translator/test/CimbWriterTest.cpp
+++ b/src/lib/cimb_translator/test/CimbWriterTest.cpp
@@ -20,5 +20,23 @@ TEST_CASE( "CimbWriterTest/testSimple", "[unit]" )
 	}
 
 	cv::Mat img = cw.image();
+	assertEquals(1024, img.cols);
+	assertEquals(1024, img.rows);
 	assertEquals( 0xeecc8800efce8c08, image_hash::average_hash(img) );
 }
+
+TEST_CASE( "CimbWriterTest/testCustomSize", "[unit]" )
+{
+	CimbWriter cw(4, 2, true, 1040);
+
+	while (1)
+	{
+		if (!cw.write(0))
+			break;
+	}
+
+	cv::Mat img = cw.image();
+	assertEquals(1040, img.cols);
+	assertEquals(1040, img.rows);
+	assertEquals( 0xab00ab02af0abfab, image_hash::average_hash(img) );
+}
diff --git a/src/lib/encoder/Encoder.h b/src/lib/encoder/Encoder.h
index 1ac9e8fe..280d376e 100644
--- a/src/lib/encoder/Encoder.h
+++ b/src/lib/encoder/Encoder.h
@@ -15,7 +15,7 @@ class Encoder : public SimpleEncoder
 	using SimpleEncoder::SimpleEncoder;
 
 	unsigned encode(const std::string& filename, std::string output_prefix);
-	unsigned encode_fountain(const std::string& filename, std::string output_prefix, int compression_level=6, double redundancy=1.2);
+	unsigned encode_fountain(const std::string& filename, std::string output_prefix, int compression_level=6, double redundancy=1.2, int canvas_size=0);
 	unsigned encode_fountain(const std::string& filename, const std::function<bool(const cv::Mat&, unsigned)>& on_frame, int compression_level=6, double redundancy=4.0, int canvas_size=0);
 };
 
@@ -67,7 +67,7 @@ inline unsigned Encoder::encode_fountain(const std::string& filename, const std:
 	return i;
 }
 
-inline unsigned Encoder::encode_fountain(const std::string& filename, std::string output_prefix, int compression_level, double redundancy)
+inline unsigned Encoder::encode_fountain(const std::string& filename, std::string output_prefix, int compression_level, double redundancy, int canvas_size)
 {
 	std::function<bool(const cv::Mat&, unsigned)> fun = [output_prefix] (const cv::Mat& frame, unsigned i) {
 		std::string output = fmt::format("{}_{}.png", output_prefix, i);
@@ -75,5 +75,5 @@ inline unsigned Encoder::encode_fountain(const std::string& filename, std::strin
 		cv::cvtColor(frame, bgr, cv::COLOR_RGB2BGR);
 		return cv::imwrite(output, bgr);
 	};
-	return encode_fountain(filename, fun, compression_level, redundancy);
+	return encode_fountain(filename, fun, compression_level, redundancy, canvas_size);
 }
diff --git a/src/lib/encoder/test/EncoderTest.cpp b/src/lib/encoder/test/EncoderTest.cpp
index 3f786af9..60c06609 100644
--- a/src/lib/encoder/test/EncoderTest.cpp
+++ b/src/lib/encoder/test/EncoderTest.cpp
@@ -33,7 +33,6 @@ TEST_CASE( "EncoderTest/testVanilla", "[unit]" )
 		{
 			std::string path = fmt::format("{}_{}.png", outPrefix, i);
 			cv::Mat img = cv::imread(path);
-			cv::cvtColor(img, img, cv::COLOR_BGR2RGB);
 			assertEquals( hashes[i], image_hash::average_hash(img) );
 		}
 	}
@@ -56,7 +55,6 @@ TEST_CASE( "EncoderTest/testFountain", "[unit]" )
 		{
 			std::string path = fmt::format("{}_{}.png", outPrefix, i);
 			cv::Mat img = cv::imread(path);
-			cv::cvtColor(img, img, cv::COLOR_BGR2RGB);
 			assertEquals( hashes[i], image_hash::average_hash(img) );
 		}
 	}
@@ -69,13 +67,12 @@ TEST_CASE( "EncoderTest/testFountain.Compress", "[unit]" )
 	std::string inputFile = TestCimbar::getProjectDir() + "/LICENSE";
 	std::string outPrefix = tempdir.path() / "encoder.fountain";
 
-	Encoder enc(40, 4, 2);
+	Encoder enc(30, 4, 2);
 	assertEquals( 1, enc.encode_fountain(inputFile, outPrefix) );
 
-	uint64_t hash = 0xf8cde200e90582e4;
+	uint64_t hash = 0x4fd34f01ee80a28d;
 	std::string path = fmt::format("{}_0.png", outPrefix);
 	cv::Mat img = cv::imread(path);
-	cv::cvtColor(img, img, cv::COLOR_BGR2RGB);
 	assertEquals( hash, image_hash::average_hash(img) );
 }
 
@@ -102,3 +99,21 @@ TEST_CASE( "EncoderTest/testPiecemealFountainEncoder", "[unit]" )
 	uint64_t hash = 0xf8cde200e90582e4;
 	assertEquals( hash, image_hash::average_hash(*frame) );
 }
+
+TEST_CASE( "EncoderTest/testFountain.Size", "[unit]" )
+{
+	MakeTempDirectory tempdir;
+
+	std::string inputFile = TestCimbar::getProjectDir() + "/LICENSE";
+	std::string outPrefix = tempdir.path() / "encoder.fountain";
+
+	Encoder enc(30, 4, 2);
+	assertEquals( 1, enc.encode_fountain(inputFile, outPrefix, 10, 2.0, 1080) );
+
+	uint64_t hash = 0x8985b70d93675786;
+	std::string path = fmt::format("{}_0.png", outPrefix);
+	cv::Mat img = cv::imread(path);
+	assertEquals( 1080, img.rows );
+	assertEquals( 1080, img.cols );
+	assertEquals( hash, image_hash::average_hash(img) );
+}

From 8e5fa906a42de4f43a02126dc4484bb94e6717d4 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Fri, 5 Mar 2021 07:18:59 -0600
Subject: [PATCH 24/26] Misc docs updates, including new performance numbers!

100 KB/s is defeated
---
 DETAILS.md     |  4 ++--
 PERFORMANCE.md | 15 ++++++++++-----
 README.md      |  6 ++++--
 TODO.md        | 15 +++++++++++----
 4 files changed, 27 insertions(+), 13 deletions(-)

diff --git a/DETAILS.md b/DETAILS.md
index 8fee47d4..e58718f9 100644
--- a/DETAILS.md
+++ b/DETAILS.md
@@ -3,7 +3,7 @@
 
 ## The premise
 
-Conceptually, cimbar is built on top of `image hashing`:
+Cimbar is a grid of colored tiles. Conceptually, it is built on the idea of `image hashing`:
 
 ![example image hash](https://github.com/sz3/cimbar-samples/blob/v0.5/docs/imagehash.png)
 
@@ -84,7 +84,7 @@ These properties may appear to be magical as you consider them more, and they do
 2. wirehair requires the file contents to be stored in RAM
 	* this relates to the size limit!
 
-This constraint is less of an obstacle than it may seem -- the fountain codes are essentially being used as a wire format, and the encoder and decoder could agree on a scheme to split up, and then reassemble, larger files. Cimbar does not yet implement this, however!
+This constraint is less of an obstacle than it may seem -- the fountain codes are essentially being used as a wire format, and the encoder and decoder could agree on a scheme to split up, and then reassemble, larger files. Cimbar does not (yet?) implement this, however!
 
 ## Implementation: Decoder
 
diff --git a/PERFORMANCE.md b/PERFORMANCE.md
index bc9d1c23..3ab9d92a 100644
--- a/PERFORMANCE.md
+++ b/PERFORMANCE.md
@@ -14,10 +14,10 @@
 ## Current sustained benchmark
 
 * 4-color cimbar with ecc=30:
-	* 2,980,556 bytes (after compression) in 31s -> 769 kilobits/s (~96 KB/s)
+	* 4,717,525 bytes (after compression) in 45s -> 838 kilobits/s (~104 KB/s)
 
 * 8-color cimbar with ecc=30:
-	* 2,980,556 bytes in 29s -> 822 kilobits/s (~102 KB/s)
+	* 4,717,525 bytes in 40s -> 943 kilobits/s (~118 KB/s)
 
 * details:
 	* these numbers are using https://github.com/sz3/cfc, running with 4 CPU threads on a Qualcomm Snapdragon 625
@@ -26,9 +26,14 @@
 		* cimbar.org uses the `shakycam` option to allow the receiver to detect/discard "in between" frames as part of the scan step. This allows it to spend more processing time decoding real data.
 	* burst rate can be higher (or lower)
 		* to this end, lower ecc settings *can* provide better burst rates
-	* 8-color cimbar is considerably more sensitive to lighting conditions and color tints. When in doubt, fall back to 4-color.
+	* 4-color cimbar is currently preferred, and will give more consistent transfer speeds.
+	* 8-color cimbar should be considered a prototype within a prototype. It is considerably more sensitive to lighting conditions and color tints.
 
 * other notes:
-		* having better lighting in the frame often leads to better results -- this is why cimbar.org has a (mostly) white background. cfc uses android's auto-exposure, auto-focus, etc (it's a very simple app). So good ambient light -- or a white background -- can lead to more consitent quality frame capture.
+		* having better lighting in the frame often leads to better results -- this is why cimbar.org has a (mostly) white background. cfc uses android's auto-exposure, auto-focus, etc (it's a very simple app). Good ambient light -- or a white background -- can lead to more consitent quality frame capture.
+		* because of the lighting/exposure question, I usually "shoot" in landscape instead of portrait.
 		* cfc currently has a low resolution, so the cimbar frame should take up as much of the display as possible (trust the guide brackets)
-		* similarly, it's best to keep the camera angle as straight-on as possible, to decode the whole image successfully. Decodes should still happen at higher angles, but the "smaller" part of the image may have more errors than the error correction can deal with.
+		* similarly, it's best to keep the camera angle straight-on -- instead of at an angle -- to decode the whole image successfully. Decodes should still happen at higher angles, but the "smaller" part of the image may have more errors than the ECC can deal with.
+		* other things to be wary of:
+			* glare from light sources.
+			* shaky hands.
diff --git a/README.md b/README.md
index c7eb1074..2d12e7d0 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@
 
 Behold: an experimental barcode format for air-gapped data transfer.
 
-It can sustain speeds of 770+ kilobits/s (~96 KB/s) using nothing but a smartphone camera!
+It can sustain speeds of 943+ kilobits/s (~118 KB/s) using just a computer monitor and a smartphone camera!
 
 ## Explain?
 
@@ -25,7 +25,9 @@ No internet/bluetooth/NFC/etc is used. All data is transmitted through the camer
 
 ## Platforms
 
-The code is written in C++, and developed/tested on amd64+linux, arm64+android, and emscripten+wasm. It probably works, or can be made to work, on other platforms.
+The code is written in C++, and developed/tested on amd64+linux, arm64+android (decoder only), and emscripten+WASM (encoder only). It probably works, or can be made to work, on other platforms.
+
+Crucially, because the encoder compiles to asmjs and wasm, it can run on anything with a modern web browser. There are [releases](https://github.com/sz3/libcimbar/releases/latest) if you wish to run the encoder locally instead of via cimbar.org.
 
 ## Library dependencies
 
diff --git a/TODO.md b/TODO.md
index 8969ff0f..48fbd553 100644
--- a/TODO.md
+++ b/TODO.md
@@ -8,7 +8,7 @@ libcimbar is fairly optimized, to achieve the *proof* part of proof-of-concept.
 Performance optimizations aside, there are a number of paths that might be interesting to pursue. Some I may take a look at, but most I will leave to any enterprising developer who wants to take up the cause:
 
 * proper metadata/header information?
-	* would be nice to be able to determine ecc/#colors/#smybols from the cimbar image itself?
+	* would be nice to be able to determine ecc/#colors/#symbols from the cimbar image itself?
 	* The bottom right corner is the obvious place to reclaim space to make this possible.
 * multi-frame decoding?
 	* when decoding a static cimbar image, it would be useful to be able to use prior (unsuccessful) decode attempts to inform a future decode, and -- hopefully -- increase the probability of success. Currently, all frames are decoded independently.
@@ -16,7 +16,7 @@ Performance optimizations aside, there are a number of paths that might be inter
 * optimal symbol set?
 	* the 16-symbol (4 bit) set is hand-drawn. I stared with ~40 or so hand-drawn symbols, and used the 16 that performed best with each other.
 	* there is surely a more optimal set -- a more rigorous approach should yield lower error rates!
-	* but, more importantly, it may be possible to go up to 32 symbols, and encode 5 bits per tile?
+	* but, more importantly, it may be possible to go up to 32 symbols, and encode 5 symbol bits per tile?
 * optimal symbol size?
 	* the symbols that make up each cell on the cimbar grid are 8x8 (in a 9x9 grid).
 	* this is because imagehash was on 8x8 tiles!
@@ -25,17 +25,24 @@ Performance optimizations aside, there are a number of paths that might be inter
 * optimal color set?
 	* the 4-color (2 bit) pallettes seem reasonable. 8-color, perhaps less so?
 	* this may be a limitation of the algorithm/approach, however. Notably, since each symbol is drawn with one pallette color, all colors need sufficient contrast against the backdrop (#000 or #FFF, depending). This constrains the color space somewhat, and less distinct colors == more errors.
+	* in addition to contrast, there is interplay (that I don't currently understand) between the overall brightness of the image and the exposure time needed for high framerate capture. More clean frames == more troughput.
 * optimal grid size?
 	* 1024x1024 is a remnant of the early prototyping process. There is nothing inherently special about it (except that it fits on a 1920x1080 screen, which seems good)
 		* the tile grid itself is 1008x1008 (1008 == 9x112 -- there are 112 tile rows and columns)
 	* a smaller grid would be less information dense, but more resilient to errors. Probably.
 * optimal grid shape?
 	* it's a square because QR codes are square. That's it. Should it be?
-	* I'm strongly considering 4:3 for the next revision
+	* I'm strongly considering 4:3 for the next revision.
 * more efficient ECC?
 	* QC-LDPC?
-	* Reed Solomon operates on bytes. Most decode errors tend to average out at 1-3 bits. In the pathological case, such a bit error will span two bytes. It's not a total disaster, because it works. However, it would be nice to use state of the art ECC.
+	* Reed Solomon operates on bytes. Most decode errors tend to average out at 1-3 bits. (In the pathological case, a single read error will span two bytes.) It's not a total disaster -- it still works. 
+	* I expect that state of the art ECC will allow 6-15% better throughput.
+		* it's a wide range due to various unknowns (unknowns to me, anyway)
 * proper GPU support (OpenCV + openCL) on android?
+	* It *might* be useful. [CFC]((https://github.com/sz3/cfc) is the current test bed for this.
+* wasm decoder?
+	* probably needs to use Web Workers
+	* in-browser GPGPU support would be interesting (but I'm not counting on it)
 * ???
 	* still reading? Of course there's more! There's always more!
 

From fc04ea6038989d49db704e645e8cd1071e1e1426 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Fri, 5 Mar 2021 07:26:16 -0600
Subject: [PATCH 25/26] more docs?

---
 PERFORMANCE.md | 1 +
 README.md      | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/PERFORMANCE.md b/PERFORMANCE.md
index 3ab9d92a..42d2647d 100644
--- a/PERFORMANCE.md
+++ b/PERFORMANCE.md
@@ -20,6 +20,7 @@
 	* 4,717,525 bytes in 40s -> 943 kilobits/s (~118 KB/s)
 
 * details:
+	* cimbar has built-in compression using zstd. What's being measured here is bits over the wire, e.g. data after compression is applied.
 	* these numbers are using https://github.com/sz3/cfc, running with 4 CPU threads on a Qualcomm Snapdragon 625
 		* perhaps I will buy a new cell phone to inflate the benchmark numbers.
 	* the sender is the cimbar.org wasm implementation. An equivalent command line is `./cimbar_send /path/to/file -s`
diff --git a/README.md b/README.md
index 2d12e7d0..8c8cd25e 100644
--- a/README.md
+++ b/README.md
@@ -7,6 +7,8 @@ Behold: an experimental barcode format for air-gapped data transfer.
 
 It can sustain speeds of 943+ kilobits/s (~118 KB/s) using just a computer monitor and a smartphone camera!
 
+![A non-animated cimbar code](https://github.com/sz3/cimbar-samples/blob/v0.5/6bit/4cecc30f.png)
+
 ## Explain?
 
 The encoder outputs an animated barcode to a computer or smartphone screen:

From 61fff8fd0147a61af63533fa1db73510232527b7 Mon Sep 17 00:00:00 2001
From: sz <sz@galacticicecube.com>
Date: Fri, 5 Mar 2021 07:38:29 -0600
Subject: [PATCH 26/26] I don't think I mentioned compression anywhere.

---
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 8c8cd25e..fe072bad 100644
--- a/README.md
+++ b/README.md
@@ -23,7 +23,7 @@ No internet/bluetooth/NFC/etc is used. All data is transmitted through the camer
 
 `cimbar` is a high-density 2D barcode format. Data is stored in a grid of colored tiles -- bits are encoded based on which tile is chosen, and which color is chosen to draw the tile. Reed Solomon error correction is applied on the data, to account for the lossy nature of the video -> digital decoding. Sub-1% error rates are expected, and corrected.
 
-`libcimbar`, this optimized implementation, includes a simple protocol for file encoding based on fountain codes (`wirehair`). Files of up to 33MB can be encoded in a series of cimbar codes, which can be output as images or a live video feed. Once enough distinct image frames have been decoded successfully, the file will be reconstructed successfully. This is true even if the images are received out of order, or if some have been corrupted or are missing.
+`libcimbar`, this optimized implementation, includes a simple protocol for file encoding built on fountain codes (`wirehair`) and zstd compression. Files of up to 33MB (after compression!) are encoded in a series of cimbar codes, which can be output as images or a live video feed. Once enough distinct image frames have been decoded successfully, the file will be reconstructed and decompressed successfully. This is true even if the images are received out of order, or if some have been corrupted or are missing.
 
 ## Platforms