From 9cdd94bcb3f9d7c91f1d6a1d43f314997893c124 Mon Sep 17 00:00:00 2001
From: Donovan Hutchence <slimbuck7@gmail.com>
Date: Tue, 28 Nov 2023 09:55:55 +0000
Subject: [PATCH 1/4] early out if inner width or height is empty

---
 src/scene/graphics/reproject-texture.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/scene/graphics/reproject-texture.js b/src/scene/graphics/reproject-texture.js
index 97712aa3d9f..b90d85f0e43 100644
--- a/src/scene/graphics/reproject-texture.js
+++ b/src/scene/graphics/reproject-texture.js
@@ -483,6 +483,10 @@ function reprojectTexture(source, target, options = {}) {
         const innerWidth = w - p * 2;
         const innerHeight = h - p * 2;
 
+        if (innerWidth <= 0 || innerHeight <= 0) {
+            return false;
+        }
+
         uvModParam.setValue([
             (innerWidth + p * 2) / innerWidth,
             (innerHeight + p * 2) / innerHeight,
@@ -535,6 +539,8 @@ function reprojectTexture(source, target, options = {}) {
     }
 
     DebugGraphics.popGpuMarker(device);
+
+    return true;
 }
 
 export { reprojectTexture };

From f305004d54fdf35bab8f6a9a756d6212592c06eb Mon Sep 17 00:00:00 2001
From: Donovan Hutchence <slimbuck7@gmail.com>
Date: Tue, 28 Nov 2023 10:30:27 +0000
Subject: [PATCH 2/4] early out on empty inner

---
 src/scene/graphics/reproject-texture.js | 30 ++++++++++++-------------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/src/scene/graphics/reproject-texture.js b/src/scene/graphics/reproject-texture.js
index b90d85f0e43..47a76fab39a 100644
--- a/src/scene/graphics/reproject-texture.js
+++ b/src/scene/graphics/reproject-texture.js
@@ -414,6 +414,15 @@ function reprojectTexture(source, target, options = {}) {
         Debug.deprecated('please use the updated pc.reprojectTexture API.');
     }
 
+    // calculate inner width and height
+    const seamPixels = options.seamPixels ?? 0;
+    const innerWidth = (options.rect?.z ?? target.width) - seamPixels * 2;
+    const innerHeight = (options.rect?.w ?? target.height) - seamPixels * 2;
+    if (innerWidth <= 0 || innerHeight <= 0) {
+        // early out if inner space is empty
+        return false;
+    }
+
     // table of distribution -> function name
     const funcNames = {
         'none': 'reproject',
@@ -475,23 +484,12 @@ function reprojectTexture(source, target, options = {}) {
     const constantParams2 = device.scope.resolve("params2");
 
     const uvModParam = device.scope.resolve("uvMod");
-    if (options?.seamPixels) {
-        const p = options.seamPixels;
-        const w = options.rect ? options.rect.z : target.width;
-        const h = options.rect ? options.rect.w : target.height;
-
-        const innerWidth = w - p * 2;
-        const innerHeight = h - p * 2;
-
-        if (innerWidth <= 0 || innerHeight <= 0) {
-            return false;
-        }
-
+    if (seamPixels > 0) {
         uvModParam.setValue([
-            (innerWidth + p * 2) / innerWidth,
-            (innerHeight + p * 2) / innerHeight,
-            -p / innerWidth,
-            -p / innerHeight
+            (innerWidth + seamPixels * 2) / innerWidth,
+            (innerHeight + seamPixels * 2) / innerHeight,
+            -seamPixels / innerWidth,
+            -seamPixels / innerHeight
         ]);
     } else {
         uvModParam.setValue([1, 1, 0, 0]);

From 6b003e633d9139c5abd50d561115ffd7f4fb495a Mon Sep 17 00:00:00 2001
From: Donovan Hutchence <slimbuck7@gmail.com>
Date: Tue, 28 Nov 2023 10:39:22 +0000
Subject: [PATCH 3/4] lint

---
 src/scene/graphics/reproject-texture.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/scene/graphics/reproject-texture.js b/src/scene/graphics/reproject-texture.js
index 47a76fab39a..b8a1e8eb53e 100644
--- a/src/scene/graphics/reproject-texture.js
+++ b/src/scene/graphics/reproject-texture.js
@@ -396,6 +396,7 @@ void main(void) {
  * 'phong', 'ggx'. Default depends on specularPower.
  * @param {import('../../core/math/vec4.js').Vec4} [options.rect] - Optional viewport rectangle.
  * @param {number} [options.seamPixels] - Optional number of seam pixels to render
+ * @returns {boolean} True if the reprojection was applied and false otherwise (e.g. if rect is empty)
  */
 function reprojectTexture(source, target, options = {}) {
     // maintain backwards compatibility with previous function signature

From 45f16beb63b1f88e32d02ed1ce2e012afd13ad04 Mon Sep 17 00:00:00 2001
From: Donovan Hutchence <slimbuck7@gmail.com>
Date: Tue, 28 Nov 2023 10:52:13 +0000
Subject: [PATCH 4/4] small

---
 src/scene/graphics/reproject-texture.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/scene/graphics/reproject-texture.js b/src/scene/graphics/reproject-texture.js
index b8a1e8eb53e..7f412ed62f2 100644
--- a/src/scene/graphics/reproject-texture.js
+++ b/src/scene/graphics/reproject-texture.js
@@ -419,7 +419,7 @@ function reprojectTexture(source, target, options = {}) {
     const seamPixels = options.seamPixels ?? 0;
     const innerWidth = (options.rect?.z ?? target.width) - seamPixels * 2;
     const innerHeight = (options.rect?.w ?? target.height) - seamPixels * 2;
-    if (innerWidth <= 0 || innerHeight <= 0) {
+    if (innerWidth < 1 || innerHeight < 1) {
         // early out if inner space is empty
         return false;
     }