Add custom shader_version on glow renderer

crates/eframe/CHANGELOG.md

@@ -8,7 +8,7 @@ NOTE: [`egui-winit`](../egui-winit/CHANGELOG.md), [`egui_glium`](../egui_glium/C
 * Added `NativeOptions::event_loop_builder` hook for apps to change platform specific event loop options ([#1952](https://github.com/emilk/egui/pull/1952)).
 * Enabled deferred render state initialization to support Android ([#1952](https://github.com/emilk/egui/pull/1952)).
 * Allow empty textures with the glow renderer.
-
+* Added `custom_shader_version` to `NativeOptions` for cross compilling support on different target OpenGL | ES versions (on native `glow` renderer only).
 
 ## 0.19.0 - 2022-08-20
 * MSRV (Minimum Supported Rust Version) is now `1.61.0` ([#1846](https://github.com/emilk/egui/pull/1846)).

crates/eframe/src/epi.rs

@@ -311,6 +311,14 @@ pub struct NativeOptions {
  ///
  /// Note: A [`NativeOptions`] clone will not include any `event_loop_builder` hook.
  pub event_loop_builder: Option<EventLoopBuilderHook>,
+
+ #[cfg(feature = "glow")]
+ /// A helper when cross compiling for different target OpenGL | ES versions.
+ ///
+ /// cross compiling for VirtualBox VMSVGA driver with OpenGL 2.1 but doesn't support SRGB texture.
+ ///
+ /// the OpenGL ES 2.0 shader: ShaderVersion::Es100 can be used to solve blank texture problem (fallback shader).
+ pub custom_shader_version: Option<egui_glow::ShaderVersion>,
 }
 
 #[cfg(not(target_arch = "wasm32"))]
@@ -350,6 +358,8 @@ impl Default for NativeOptions {
  default_theme: Theme::Dark,
  run_and_return: true,
  event_loop_builder: None,
+ #[cfg(feature = "glow")]
+ custom_shader_version: None,
  }
  }
 }

crates/eframe/src/native/run.rs

@@ -337,8 +337,13 @@ mod glow_integration {
  );
  let gl = Arc::new(gl);
 
- let painter = egui_glow::Painter::new(gl.clone(), None, "")
- .unwrap_or_else(|error| panic!("some OpenGL error occurred {}\n", error));
+ let painter = egui_glow::Painter::new(
+ gl.clone(),
+ None,
+ "",
+ self.native_options.custom_shader_version,
+ )
+ .unwrap_or_else(|error| panic!("some OpenGL error occurred {}\n", error));
 
  let system_theme = self.native_options.system_theme();
  let mut integration = epi_integration::EpiIntegration::new(

crates/eframe/src/web/web_glow_painter.rs

@@ -23,7 +23,7 @@ impl WebPainter {
  let gl = std::sync::Arc::new(gl);
 
  let dimension = [canvas.width() as i32, canvas.height() as i32];
- let painter = egui_glow::Painter::new(gl, Some(dimension), shader_prefix)
+ let painter = egui_glow::Painter::new(gl, Some(dimension), shader_prefix, None)
  .map_err(|error| format!("Error starting glow painter: {}", error))?;
 
  Ok(Self {

crates/egui_glow/CHANGELOG.md

@@ -4,7 +4,7 @@ All notable changes to the `egui_glow` integration will be noted in this file.
 
 ## Unreleased
 * Allow empty textures.
-
+* small BREAKING change: Added `custom_shader_version` variable on `EguiGlow::new` for easier cross compilling on different OpenGL | ES targets.
 
 ## 0.19.0 - 2022-08-20
 * MSRV (Minimum Supported Rust Version) is now `1.61.0` ([#1846](https://github.com/emilk/egui/pull/1846)).

crates/egui_glow/examples/pure_glow.rs

@@ -10,7 +10,7 @@ fn main() {
  let (gl_window, gl) = create_display(&event_loop);
  let gl = std::sync::Arc::new(gl);
 
- let mut egui_glow = egui_glow::EguiGlow::new(&event_loop, gl.clone());
+ let mut egui_glow = egui_glow::EguiGlow::new(&event_loop, gl.clone(), None);
 
  event_loop.run(move |event, _, control_flow| {
  let mut redraw = || {

crates/egui_glow/src/painter.rs

@@ -106,13 +106,16 @@ impl Painter {
  gl: Arc<glow::Context>,
  pp_fb_extent: Option<[i32; 2]>,
  shader_prefix: &str,
+ custom_shader_version: Option<ShaderVersion>,
  ) -> Result<Painter, String> {
  crate::profile_function!();
  crate::check_for_gl_error_even_in_release!(&gl, "before Painter::new");
 
  let max_texture_side = unsafe { gl.get_parameter_i32(glow::MAX_TEXTURE_SIZE) } as usize;
-
- let shader_version = ShaderVersion::get(&gl);
+ let shader_version = match custom_shader_version {
+ Some(version) => version,
+ _ => ShaderVersion::get(&gl),
+ };
  let is_webgl_1 = shader_version == ShaderVersion::Es100;
  let header = shader_version.version_declaration();
  tracing::debug!("Shader header: {:?}.", header);

crates/egui_glow/src/winit.rs

@@ -1,7 +1,7 @@
+use crate::shader_version::ShaderVersion;
 pub use egui_winit;
-pub use egui_winit::EventResponse;
-
 use egui_winit::winit;
+pub use egui_winit::EventResponse;
 
 /// Use [`egui`] from a [`glow`] app based on [`winit`].
 pub struct EguiGlow {
@@ -14,11 +14,13 @@ pub struct EguiGlow {
 }
 
 impl EguiGlow {
+ /// for automatic shader version detection set `custom_shader_version` to None
  pub fn new<E>(
  event_loop: &winit::event_loop::EventLoopWindowTarget<E>,
  gl: std::sync::Arc<glow::Context>,
+ custom_shader_version: Option<ShaderVersion>,
  ) -> Self {
- let painter = crate::Painter::new(gl, None, "")
+ let painter = crate::Painter::new(gl, None, "", custom_shader_version)
  .map_err(|error| {
  tracing::error!("error occurred in initializing painter:\n{}", error);
  })

examples/retained_image/src/main.rs

@@ -8,6 +8,7 @@ fn main() {
  initial_window_size: Some(egui::vec2(500.0, 900.0)),
  ..Default::default()
  };
+
  eframe::run_native(
  "Show an image with eframe/egui",
  options,