Bug 1591436 - Avoid using glTexImage3D on android emulator. r=gw

A bug in the android emulator means that glTexImage3D thinks the maximum texture
size is the value of GL_MAX_TEXTURE_SIZE, rather than the value returned by
glGetIntegerv(GL_MAX_TEXTURE_SIZE). This means that calls to glTexImage3D fail
when width, height, or depth > 3379.

This forces us to use glTexStorage3D instead of glTexImage3D, avoiding
this bug. This relies upon swizzling, which is indeed supported on the
android emulator.

Differential Revision: https://phabricator.services.mozilla.com/D51293

--HG--
extra : moz-landing-system : lando

gfx/wr/webrender/src/device/gl.rs

@@ -1325,6 +1325,11 @@ impl Device {
         // GL_EXT_texture_storage and GL_EXT_texture_format_BGRA8888.
         let supports_gles_bgra = supports_extension(&extensions, "GL_EXT_texture_format_BGRA8888");
 
+        // On the android emulator glTexImage fails to create textures larger than 3379.
+        // So we must use glTexStorage instead. See bug 1591436.
+        let is_emulator = renderer_name.starts_with("Android Emulator");
+        let avoid_tex_image = is_emulator;
+
         let (color_formats, bgra_formats, bgra8_sampling_swizzle, texture_storage_usage) = match gl.get_type() {
             // There is `glTexStorage`, use it and expect RGBA on the input.
             gl::GlType::Gl if
@@ -1355,7 +1360,7 @@ impl Device {
             // format and glTexImage. If texture storage is supported we can
             // use it for other formats.
             // We can't use glTexStorage with BGRA8 as the internal format.
-            gl::GlType::Gles if supports_gles_bgra => (
+            gl::GlType::Gles if supports_gles_bgra && !avoid_tex_image => (
                 TextureFormatPair::from(ImageFormat::RGBA8),
                 TextureFormatPair::from(gl::BGRA_EXT),
                 Swizzle::Rgba, // no conversion needed