Use GL_BGRA_EXT format with ANGLE.

ui/gl/gl_image.cpp

@@ -91,11 +91,11 @@ void Image::bind(QOpenGLFunctions &f) {
 			f.glTexImage2D(
 				GL_TEXTURE_2D,
 				0,
-				GL_RGBA,
+				kFormatRGBA,
 				_subimage.width(),
 				_subimage.height(),
 				0,
-				GL_RGBA,
+				kFormatRGBA,
 				GL_UNSIGNED_BYTE,
 				_image.constBits());
 		} else {
@@ -106,7 +106,7 @@ void Image::bind(QOpenGLFunctions &f) {
 				0,
 				_subimage.width(),
 				_subimage.height(),
-				GL_RGBA,
+				kFormatRGBA,
 				GL_UNSIGNED_BYTE,
 				_image.constBits());
 		}

ui/gl/gl_image.h

@@ -136,4 +136,12 @@ private:
 
 [[nodiscard]] GLint CurrentSingleComponentFormat();
 
+#ifdef Q_OS_WIN
+inline constexpr auto kFormatRGBA = GL_BGRA_EXT;
+inline constexpr auto kSwizzleRedBlue = false;
+#else // Q_OS_WIN
+inline constexpr auto kFormatRGBA = GL_RGBA;
+inline constexpr auto kSwizzleRedBlue = true;
+#endif // Q_OS_WIN
+
 } // namespace Ui::GL

ui/gl/gl_primitives.h

@@ -25,7 +25,6 @@ void FillTriangles(
 	const QColor &color,
 	Fn<void()> additional = nullptr);
 
-
 void FillRectangle(
 	QOpenGLFunctions &f,
 	not_null<QOpenGLShaderProgram*> program,

ui/gl/gl_shader.cpp

@@ -6,6 +6,7 @@
 //
 #include "ui/gl/gl_shader.h"
 
+#include "ui/gl/gl_image.h"
 #include "base/debug_log.h"
 
 #include <QtGui/QOpenGLContext>
@@ -72,8 +73,10 @@ uniform sampler2D s_texture;
 )",
 		.body = R"(
 	result = texture2D(s_texture, v_texcoord);
+)" + (kSwizzleRedBlue
+	? R"(
 	result = vec4(result.b, result.g, result.r, result.a);
-)",
+)" : QString()),
 	};
 }