gl-renderer: Replace channel ordering with texture swizzles

The channel ordering system currently proposes to swizzle components
in the fragment shader for a few combinations. This commit replaces
this system with texture swizzling parameters in order to support all
the possible combinations in a more efficient way.

This will allow to easily add a lot more formats and as a nice side
effect to force components to 0 or 1, which is useful for opaque
formats.

Signed-off-by: Loïc Molinari <loic.molinari@collabora.com>

libweston/pixel-formats.c

@@ -51,29 +51,41 @@
 #include <GLES2/gl2ext.h>
 #include <GLES3/gl3.h>
 
-#define GL_FORMAT_INFO(internal_, external_, type_) \
+#define SWIZZLES_ABG1 { GL_ALPHA, GL_BLUE,  GL_GREEN, GL_ONE   }
+#define SWIZZLES_ABGR { GL_ALPHA, GL_BLUE,  GL_GREEN, GL_RED   }
+#define SWIZZLES_B1RG { GL_BLUE,  GL_ONE,   GL_RED,   GL_GREEN }
+#define SWIZZLES_BARG { GL_BLUE,  GL_ALPHA, GL_RED,   GL_GREEN }
+#define SWIZZLES_BGR1 { GL_BLUE,  GL_GREEN, GL_RED,   GL_ONE   }
+#define SWIZZLES_BGRA { GL_BLUE,  GL_GREEN, GL_RED,   GL_ALPHA }
+#define SWIZZLES_GBA1 { GL_GREEN, GL_BLUE,  GL_ALPHA, GL_ONE   }
+#define SWIZZLES_GBAR { GL_GREEN, GL_BLUE,  GL_ALPHA, GL_RED   }
+#define SWIZZLES_R001 { GL_RED,   GL_ZERO,  GL_ZERO,  GL_ONE   }
+#define SWIZZLES_RG01 { GL_RED,   GL_GREEN, GL_ZERO,  GL_ONE   }
+#define SWIZZLES_RGB1 { GL_RED,   GL_GREEN, GL_BLUE,  GL_ONE   }
+#define SWIZZLES_RGBA { GL_RED,   GL_GREEN, GL_BLUE,  GL_ALPHA }
+
+#define GL_FORMAT_INFO(internal_, external_, type_, swizzles_) \
 	.gl = { \
 		.internal = internal_, \
 		.external = external_, \
 		.type = type_, \
+		.swizzles.array = SWIZZLES_ ## swizzles_, \
 	}
 #define GL_INTERNALFORMAT(fmt) .gl_internalformat = (fmt)
 #define GL_FORMAT(fmt) .gl_format = (fmt)
 #define GL_TYPE(type) .gl_type = (type)
-#define GL_CHANNEL_ORDER(order) \
-	.gl_channel_order = (SHADER_CHANNEL_ORDER_ ## order)
 #define SAMPLER_TYPE(type) .sampler_type = (type)
 #else
-#define GL_FORMAT_INFO(internal_, external_, type_) \
+#define GL_FORMAT_INFO(internal_, external_, type_, swizzles_) \
 	.gl = { \
 		.internal = 0, \
 		.external = 0, \
 		.type = 0, \
+		.swizzles.array = { 0, 0, 0, 0 }, \
 	}
 #define GL_INTERNALFORMAT(fmt) .gl_internalformat = 0
 #define GL_FORMAT(fmt) .gl_format = 0
 #define GL_TYPE(type) .gl_type = 0
-#define GL_CHANNEL_ORDER(order) .gl_channel_order = 0
 #define SAMPLER_TYPE(type) .sampler_type = 0
 #endif
 
@@ -106,7 +118,7 @@ static const struct pixel_format_info pixel_format_table[] = {
 		BITS_RGBA_FIXED(8, 0, 0, 0),
 		.bpp = 8,
 		.hide_from_clients = true,
-		GL_FORMAT_INFO(GL_R8, GL_RED, GL_UNSIGNED_BYTE),
+		GL_FORMAT_INFO(GL_R8, GL_RED, GL_UNSIGNED_BYTE, R001),
 		GL_FORMAT(GL_R8_EXT),
 		GL_TYPE(GL_UNSIGNED_BYTE),
 	},
@@ -115,7 +127,7 @@ static const struct pixel_format_info pixel_format_table[] = {
 		BITS_RGBA_FIXED(8, 8, 0, 0),
 		.bpp = 16,
 		.hide_from_clients = true,
-		GL_FORMAT_INFO(GL_RG8, GL_RG, GL_UNSIGNED_BYTE),
+		GL_FORMAT_INFO(GL_RG8, GL_RG, GL_UNSIGNED_BYTE, RG01),
 		GL_FORMAT(GL_RG8_EXT),
 		GL_TYPE(GL_UNSIGNED_BYTE),
 	},
@@ -146,9 +158,11 @@ static const struct pixel_format_info pixel_format_table[] = {
 		BITS_RGBA_FIXED(4, 4, 4, 0),
 		.bpp = 16,
 #if __BYTE_ORDER == __LITTLE_ENDIAN
-		GL_FORMAT_INFO(GL_RGBA4, GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4),
+		GL_FORMAT_INFO(GL_RGBA4, GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, RGB1),
 		GL_FORMAT(GL_RGBA),
 		GL_TYPE(GL_UNSIGNED_SHORT_4_4_4_4),
+#else
+		GL_FORMAT_INFO(GL_RGBA4, GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, B1RG),
 #endif
 	},
 	{
@@ -157,9 +171,11 @@ static const struct pixel_format_info pixel_format_table[] = {
 		.bpp = 16,
 		.opaque_substitute = DRM_FORMAT_RGBX4444,
 #if __BYTE_ORDER == __LITTLE_ENDIAN
-		GL_FORMAT_INFO(GL_RGBA4, GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4),
+		GL_FORMAT_INFO(GL_RGBA4, GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, RGBA),
 		GL_FORMAT(GL_RGBA),
 		GL_TYPE(GL_UNSIGNED_SHORT_4_4_4_4),
+#else
+		GL_FORMAT_INFO(GL_RGBA4, GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, BARG),
 #endif
 	},
 	{
@@ -201,7 +217,7 @@ static const struct pixel_format_info pixel_format_table[] = {
 		BITS_RGBA_FIXED(5, 5, 5, 0),
 		.bpp = 16,
 #if __BYTE_ORDER == __LITTLE_ENDIAN
-		GL_FORMAT_INFO(GL_RGB5_A1, GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1),
+		GL_FORMAT_INFO(GL_RGB5_A1, GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1, RGB1),
 		GL_FORMAT(GL_RGBA),
 		GL_TYPE(GL_UNSIGNED_SHORT_5_5_5_1),
 #endif
@@ -212,7 +228,7 @@ static const struct pixel_format_info pixel_format_table[] = {
 		.bpp = 16,
 		.opaque_substitute = DRM_FORMAT_RGBX5551,
 #if __BYTE_ORDER == __LITTLE_ENDIAN
-		GL_FORMAT_INFO(GL_RGB5_A1, GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1),
+		GL_FORMAT_INFO(GL_RGB5_A1, GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1, RGBA),
 		GL_FORMAT(GL_RGBA),
 		GL_TYPE(GL_UNSIGNED_SHORT_5_5_5_1),
 #endif
@@ -234,7 +250,7 @@ static const struct pixel_format_info pixel_format_table[] = {
 		.addfb_legacy_depth = 16,
 		.bpp = 16,
 #if __BYTE_ORDER == __LITTLE_ENDIAN
-		GL_FORMAT_INFO(GL_RGB565, GL_RGB, GL_UNSIGNED_SHORT_5_6_5),
+		GL_FORMAT_INFO(GL_RGB565, GL_RGB, GL_UNSIGNED_SHORT_5_6_5, RGB1),
 		GL_FORMAT(GL_RGB),
 		GL_TYPE(GL_UNSIGNED_SHORT_5_6_5),
 		PIXMAN_FMT(r5g6b5),
@@ -249,16 +265,15 @@ static const struct pixel_format_info pixel_format_table[] = {
 		DRM_FORMAT(RGB888),
 		BITS_RGBA_FIXED(8, 8, 8, 0),
 		.bpp = 24,
-		GL_FORMAT_INFO(GL_RGB8, GL_RGB, GL_UNSIGNED_BYTE),
+		GL_FORMAT_INFO(GL_RGB8, GL_RGB, GL_UNSIGNED_BYTE, RGB1),
 		GL_FORMAT(GL_RGB),
 		GL_TYPE(GL_UNSIGNED_BYTE),
-		GL_CHANNEL_ORDER(BGRA),
 	},
 	{
 		DRM_FORMAT(BGR888),
 		BITS_RGBA_FIXED(8, 8, 8, 0),
 		.bpp = 24,
-		GL_FORMAT_INFO(GL_RGB8, GL_RGB, GL_UNSIGNED_BYTE),
+		GL_FORMAT_INFO(GL_RGB8, GL_RGB, GL_UNSIGNED_BYTE, BGR1),
 		GL_FORMAT(GL_RGB),
 		GL_TYPE(GL_UNSIGNED_BYTE),
 	},
@@ -267,7 +282,7 @@ static const struct pixel_format_info pixel_format_table[] = {
 		BITS_RGBA_FIXED(8, 8, 8, 0),
 		.addfb_legacy_depth = 24,
 		.bpp = 32,
-		GL_FORMAT_INFO(GL_BGRA8_EXT, GL_BGRA_EXT, GL_UNSIGNED_BYTE),
+		GL_FORMAT_INFO(GL_BGRA8_EXT, GL_BGRA_EXT, GL_UNSIGNED_BYTE, RGB1),
 		GL_INTERNALFORMAT(GL_RGB8),
 		GL_FORMAT(GL_BGRA_EXT),
 		GL_TYPE(GL_UNSIGNED_BYTE),
@@ -283,7 +298,7 @@ static const struct pixel_format_info pixel_format_table[] = {
 		.opaque_substitute = DRM_FORMAT_XRGB8888,
 		.addfb_legacy_depth = 32,
 		.bpp = 32,
-		GL_FORMAT_INFO(GL_BGRA8_EXT, GL_BGRA_EXT, GL_UNSIGNED_BYTE),
+		GL_FORMAT_INFO(GL_BGRA8_EXT, GL_BGRA_EXT, GL_UNSIGNED_BYTE, RGBA),
 		GL_INTERNALFORMAT(GL_RGBA8),
 		GL_FORMAT(GL_BGRA_EXT),
 		GL_TYPE(GL_UNSIGNED_BYTE),
@@ -297,7 +312,7 @@ static const struct pixel_format_info pixel_format_table[] = {
 		DRM_FORMAT(XBGR8888),
 		BITS_RGBA_FIXED(8, 8, 8, 0),
 		.bpp = 32,
-		GL_FORMAT_INFO(GL_RGBA8, GL_RGBA, GL_UNSIGNED_BYTE),
+		GL_FORMAT_INFO(GL_RGBA8, GL_RGBA, GL_UNSIGNED_BYTE, RGB1),
 		GL_FORMAT(GL_RGBA),
 		GL_TYPE(GL_UNSIGNED_BYTE),
 #if __BYTE_ORDER == __LITTLE_ENDIAN
@@ -311,7 +326,7 @@ static const struct pixel_format_info pixel_format_table[] = {
 		BITS_RGBA_FIXED(8, 8, 8, 8),
 		.bpp = 32,
 		.opaque_substitute = DRM_FORMAT_XBGR8888,
-		GL_FORMAT_INFO(GL_RGBA8, GL_RGBA, GL_UNSIGNED_BYTE),
+		GL_FORMAT_INFO(GL_RGBA8, GL_RGBA, GL_UNSIGNED_BYTE, RGBA),
 		GL_FORMAT(GL_RGBA),
 		GL_TYPE(GL_UNSIGNED_BYTE),
 #if __BYTE_ORDER == __LITTLE_ENDIAN
@@ -324,10 +339,9 @@ static const struct pixel_format_info pixel_format_table[] = {
 		DRM_FORMAT(RGBX8888),
 		BITS_RGBA_FIXED(8, 8, 8, 0),
 		.bpp = 32,
-		GL_FORMAT_INFO(GL_RGBA8, GL_RGBA, GL_UNSIGNED_BYTE),
+		GL_FORMAT_INFO(GL_RGBA8, GL_RGBA, GL_UNSIGNED_BYTE, ABG1),
 		GL_FORMAT(GL_RGBA),
 		GL_TYPE(GL_UNSIGNED_BYTE),
-		GL_CHANNEL_ORDER(ABGR),
 #if __BYTE_ORDER == __LITTLE_ENDIAN
 		PIXMAN_FMT(r8g8b8x8),
 #else
@@ -339,10 +353,9 @@ static const struct pixel_format_info pixel_format_table[] = {
 		BITS_RGBA_FIXED(8, 8, 8, 8),
 		.bpp = 32,
 		.opaque_substitute = DRM_FORMAT_RGBX8888,
-		GL_FORMAT_INFO(GL_RGBA8, GL_RGBA, GL_UNSIGNED_BYTE),
+		GL_FORMAT_INFO(GL_RGBA8, GL_RGBA, GL_UNSIGNED_BYTE, ABGR),
 		GL_FORMAT(GL_RGBA),
 		GL_TYPE(GL_UNSIGNED_BYTE),
-		GL_CHANNEL_ORDER(ABGR),
 #if __BYTE_ORDER == __LITTLE_ENDIAN
 		PIXMAN_FMT(r8g8b8a8),
 #else
@@ -353,10 +366,9 @@ static const struct pixel_format_info pixel_format_table[] = {
 		DRM_FORMAT(BGRX8888),
 		BITS_RGBA_FIXED(8, 8, 8, 0),
 		.bpp = 32,
-		GL_FORMAT_INFO(GL_RGBA8, GL_RGBA, GL_UNSIGNED_BYTE),
+		GL_FORMAT_INFO(GL_RGBA8, GL_RGBA, GL_UNSIGNED_BYTE, GBA1),
 		GL_FORMAT(GL_RGBA),
 		GL_TYPE(GL_UNSIGNED_BYTE),
-		GL_CHANNEL_ORDER(ARGB),
 #if __BYTE_ORDER == __LITTLE_ENDIAN
 		PIXMAN_FMT(b8g8r8x8),
 #else
@@ -368,10 +380,9 @@ static const struct pixel_format_info pixel_format_table[] = {
 		BITS_RGBA_FIXED(8, 8, 8, 8),
 		.bpp = 32,
 		.opaque_substitute = DRM_FORMAT_BGRX8888,
-		GL_FORMAT_INFO(GL_RGBA8, GL_RGBA, GL_UNSIGNED_BYTE),
+		GL_FORMAT_INFO(GL_RGBA8, GL_RGBA, GL_UNSIGNED_BYTE, GBAR),
 		GL_FORMAT(GL_RGBA),
 		GL_TYPE(GL_UNSIGNED_BYTE),
-		GL_CHANNEL_ORDER(ARGB),
 #if __BYTE_ORDER == __LITTLE_ENDIAN
 		PIXMAN_FMT(b8g8r8a8),
 #else
@@ -385,6 +396,7 @@ static const struct pixel_format_info pixel_format_table[] = {
 		.bpp = 32,
 		GL_INTERNALFORMAT(GL_RGB10_A2),
 #if __BYTE_ORDER == __LITTLE_ENDIAN
+		GL_FORMAT_INFO(GL_RGB10_A2, GL_RGBA, GL_UNSIGNED_INT_2_10_10_10_REV, BGR1),
 		PIXMAN_FMT(x2r10g10b10),
 #endif
 	},
@@ -395,6 +407,7 @@ static const struct pixel_format_info pixel_format_table[] = {
 		.opaque_substitute = DRM_FORMAT_XRGB2101010,
 		GL_INTERNALFORMAT(GL_RGB10_A2),
 #if __BYTE_ORDER == __LITTLE_ENDIAN
+		GL_FORMAT_INFO(GL_RGB10_A2, GL_RGBA, GL_UNSIGNED_INT_2_10_10_10_REV, BGRA),
 		PIXMAN_FMT(a2r10g10b10),
 #endif
 	},
@@ -403,7 +416,7 @@ static const struct pixel_format_info pixel_format_table[] = {
 		BITS_RGBA_FIXED(10, 10, 10, 0),
 		.bpp = 32,
 #if __BYTE_ORDER == __LITTLE_ENDIAN
-		GL_FORMAT_INFO(GL_RGB10_A2, GL_RGBA, GL_UNSIGNED_INT_2_10_10_10_REV),
+		GL_FORMAT_INFO(GL_RGB10_A2, GL_RGBA, GL_UNSIGNED_INT_2_10_10_10_REV, RGB1),
 		GL_FORMAT(GL_RGBA),
 		GL_TYPE(GL_UNSIGNED_INT_2_10_10_10_REV_EXT),
 		PIXMAN_FMT(x2b10g10r10),
@@ -415,7 +428,7 @@ static const struct pixel_format_info pixel_format_table[] = {
 		.bpp = 32,
 		.opaque_substitute = DRM_FORMAT_XBGR2101010,
 #if __BYTE_ORDER == __LITTLE_ENDIAN
-		GL_FORMAT_INFO(GL_RGB10_A2, GL_RGBA, GL_UNSIGNED_INT_2_10_10_10_REV),
+		GL_FORMAT_INFO(GL_RGB10_A2, GL_RGBA, GL_UNSIGNED_INT_2_10_10_10_REV, RGBA),
 		GL_FORMAT(GL_RGBA),
 		GL_TYPE(GL_UNSIGNED_INT_2_10_10_10_REV_EXT),
 		PIXMAN_FMT(a2b10g10r10),
@@ -447,7 +460,7 @@ static const struct pixel_format_info pixel_format_table[] = {
 		DRM_FORMAT(XBGR16161616),
 		BITS_RGBA_FIXED(16, 16, 16, 0),
 		.bpp = 64,
-		GL_FORMAT_INFO(GL_RGBA16_EXT, GL_RGBA, GL_UNSIGNED_SHORT),
+		GL_FORMAT_INFO(GL_RGBA16_EXT, GL_RGBA, GL_UNSIGNED_SHORT, RGB1),
 #if __BYTE_ORDER__ == __LITTLE_ENDIAN
 		GL_FORMAT(GL_RGBA16_EXT),
 		GL_TYPE(GL_UNSIGNED_SHORT),
@@ -458,7 +471,7 @@ static const struct pixel_format_info pixel_format_table[] = {
 		BITS_RGBA_FIXED(16, 16, 16, 16),
 		.bpp = 64,
 		.opaque_substitute = DRM_FORMAT_XBGR16161616,
-		GL_FORMAT_INFO(GL_RGBA16_EXT, GL_RGBA, GL_UNSIGNED_SHORT),
+		GL_FORMAT_INFO(GL_RGBA16_EXT, GL_RGBA, GL_UNSIGNED_SHORT, RGBA),
 #if __BYTE_ORDER__ == __LITTLE_ENDIAN
 		GL_FORMAT(GL_RGBA16_EXT),
 		GL_TYPE(GL_UNSIGNED_SHORT),
@@ -468,7 +481,7 @@ static const struct pixel_format_info pixel_format_table[] = {
 		DRM_FORMAT(XBGR16161616F),
 		BITS_RGBA_FLOAT(16, 16, 16, 0),
 		.bpp = 64,
-		GL_FORMAT_INFO(GL_RGBA16F, GL_RGBA, GL_HALF_FLOAT),
+		GL_FORMAT_INFO(GL_RGBA16F, GL_RGBA, GL_HALF_FLOAT, RGB1),
 #if __BYTE_ORDER__ == __LITTLE_ENDIAN
 		GL_FORMAT(GL_RGBA16F),
 		GL_TYPE(GL_HALF_FLOAT),
@@ -479,7 +492,7 @@ static const struct pixel_format_info pixel_format_table[] = {
 		BITS_RGBA_FLOAT(16, 16, 16, 16),
 		.bpp = 64,
 		.opaque_substitute = DRM_FORMAT_XBGR16161616F,
-		GL_FORMAT_INFO(GL_RGBA16F, GL_RGBA, GL_HALF_FLOAT),
+		GL_FORMAT_INFO(GL_RGBA16F, GL_RGBA, GL_HALF_FLOAT, RGBA),
 #if __BYTE_ORDER__ == __LITTLE_ENDIAN
 		GL_FORMAT(GL_RGBA16F),
 		GL_TYPE(GL_HALF_FLOAT),

libweston/pixel-formats.h

@@ -28,14 +28,6 @@
 #include <stdbool.h>
 #include <pixman.h>
 
-/* Keep the following in sync with fragment.glsl. */
-enum gl_channel_order {
-	SHADER_CHANNEL_ORDER_RGBA = 0,
-	SHADER_CHANNEL_ORDER_BGRA,
-	SHADER_CHANNEL_ORDER_ARGB,
-	SHADER_CHANNEL_ORDER_ABGR,
-};
-
 /**
  * GL format information to create and manage texture and renderbuffer objects.
  */
@@ -55,9 +47,20 @@ struct gl_format_info {
 	 *  DRM_FORMAT_RGBA8888 maps to GL_RGBA / GL_UNSIGNED_BYTE). However, GL
 	 *  depends on CPU endianness for special types packing all components
 	 *  in a single type (e.g. DRM_FORMAT_RGBA4444 maps to GL_RGBA /
-	 *  GL_UNSIGNED_SHORT_4_4_4_4). */
+	 *  GL_UNSIGNED_SHORT_4_4_4_4). Different swizzles (see below) must be
+	 *  provided in that case in order to support the format on both
+	 *  little-endian and big-endian CPUs (e.g. RGBA on little-endian CPUs
+	 *  and BARG on big-endian CPUs for DRM_FORMAT_RGBA4444).*/
 	unsigned int external;
 	unsigned int type;
+
+	/** Swizzles to reorder color components of texture samples. Supported
+	 *  values are: GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_ZERO and
+	 * GL_ONE. */
+	union {
+		struct { int r, g, b, a; };
+		int array[4];
+	} swizzles;
 };
 
 /**
@@ -113,11 +116,6 @@ struct pixel_format_info {
 	/** GL data type, if data can be natively/directly uploaded. */
 	int gl_type;
 
-	/** This enumeration tells the resulting order of the color channels
-	 * when the DRM formatted pixel data is read with the given gl_format
-	 * and gl_type. */
-	enum gl_channel_order gl_channel_order;
-
 	/** Pixman data type, if it agrees exactly with the wl_shm format */
 	pixman_format_code_t pixman_format;
 

libweston/renderer-gl/fragment.glsl

@@ -54,12 +54,6 @@
 #define SHADER_COLOR_MAPPING_3DLUT 1
 #define SHADER_COLOR_MAPPING_MATRIX 2
 
-/* enum gl_channel_order */
-#define SHADER_CHANNEL_ORDER_RGBA 0
-#define SHADER_CHANNEL_ORDER_BGRA 1
-#define SHADER_CHANNEL_ORDER_ARGB 2
-#define SHADER_CHANNEL_ORDER_ABGR 3
-
 #if DEF_VARIANT == SHADER_VARIANT_EXTERNAL
 #extension GL_OES_EGL_image_external : require
 #endif
@@ -84,7 +78,6 @@ compile_const int c_variant = DEF_VARIANT;
 compile_const int c_color_pre_curve = DEF_COLOR_PRE_CURVE;
 compile_const int c_color_mapping = DEF_COLOR_MAPPING;
 compile_const int c_color_post_curve = DEF_COLOR_POST_CURVE;
-compile_const int c_color_channel_order = DEF_COLOR_CHANNEL_ORDER;
 
 compile_const bool c_input_is_premult = DEF_INPUT_IS_PREMULT;
 compile_const bool c_tint = DEF_TINT;
@@ -173,16 +166,7 @@ sample_input_texture()
 
 	if (c_variant == SHADER_VARIANT_RGBA ||
 	    c_variant == SHADER_VARIANT_RGBX) {
-		vec4 color;
-
-		if (c_color_channel_order == SHADER_CHANNEL_ORDER_BGRA)
-			color = texture2D(tex, v_texcoord).bgra;
-		else if (c_color_channel_order == SHADER_CHANNEL_ORDER_ARGB)
-			color = texture2D(tex, v_texcoord).gbar;
-		else if (c_color_channel_order == SHADER_CHANNEL_ORDER_ABGR)
-			color = texture2D(tex, v_texcoord).abgr;
-		else
-			color = texture2D(tex, v_texcoord);
+		vec4 color = texture2D(tex, v_texcoord);
 
 		if (c_variant == SHADER_VARIANT_RGBX)
 			color.a = 1.0;

libweston/renderer-gl/gl-renderer-internal.h

@@ -287,13 +287,12 @@ struct gl_shader_requirements
 	unsigned color_pre_curve:2; /* enum gl_shader_color_curve */
 	unsigned color_mapping:2; /* enum gl_shader_color_mapping */
 	unsigned color_post_curve:2; /* enum gl_shader_color_curve */
-	unsigned color_channel_order:2; /* enum gl_channel_order */
 
 	/*
 	 * The total size of all bitfields plus pad_bits_ must fill up exactly
 	 * how many bytes the compiler allocates for them together.
 	 */
-	unsigned pad_bits_:16;
+	unsigned pad_bits_:18;
 };
 static_assert(sizeof(struct gl_shader_requirements) ==
 	      4 /* total bitfield size in bytes */,

libweston/renderer-gl/gl-renderer.c

@@ -237,7 +237,6 @@ struct gl_buffer_state {
 
 	/* Only needed between attach() and flush_damage() */
 	int pitch; /* plane 0 pitch in pixels */
-	enum gl_channel_order gl_channel_order;
 	int offset[3]; /* per-plane pitch in bytes */
 
 	EGLImageKHR images[3];
@@ -1347,7 +1346,6 @@ gl_shader_config_set_input_textures(struct gl_shader_config *sconf,
 				    struct gl_buffer_state *gb)
 {
 	sconf->req.variant = gb->shader_variant;
-	sconf->req.color_channel_order = gb->gl_channel_order;
 	sconf->req.input_is_premult =
 		gl_shader_texture_variant_can_be_premult(gb->shader_variant);
 
@@ -2861,7 +2859,6 @@ gl_renderer_attach_shm(struct weston_surface *es, struct weston_buffer *buffer)
 	gb->pitch = pitch;
 	gb->shader_variant = shader_variant;
 	ARRAY_COPY(gb->offset, offset);
-	gb->gl_channel_order = buffer->pixel_format->gl_channel_order;
 	ARRAY_COPY(gb->texture_format, texture_format);
 	gb->needs_full_upload = true;
 	gb->num_textures = num_planes;
@@ -2876,7 +2873,8 @@ gl_renderer_attach_shm(struct weston_surface *es, struct weston_buffer *buffer)
 				   buffer->width / hsub, buffer->height / vsub,
 				   &gb->textures[i]);
 		gl_texture_parameters_init(gr, &gb->parameters[i],
-					   GL_TEXTURE_2D, NULL, NULL, NULL,
+					   GL_TEXTURE_2D, NULL, NULL,
+					   texture_format[i].swizzles.array,
 					   false);
 	}
 }

libweston/renderer-gl/gl-shaders.c

@@ -155,21 +155,6 @@ gl_shader_color_mapping_to_string(enum gl_shader_color_mapping kind)
 	return "!?!?"; /* never reached */
 }
 
-static const char *
-gl_shader_color_order_to_string(enum gl_channel_order kind)
-{
-	switch (kind) {
-#define CASERET(x) case x: return #x;
-	CASERET(SHADER_CHANNEL_ORDER_RGBA)
-	CASERET(SHADER_CHANNEL_ORDER_BGRA)
-	CASERET(SHADER_CHANNEL_ORDER_ARGB)
-	CASERET(SHADER_CHANNEL_ORDER_ABGR)
-#undef CASERET
-	}
-
-	return "!?!?"; /* never reached */
-}
-
 static void
 dump_program_with_line_numbers(int count, const char **sources)
 {
@@ -235,13 +220,12 @@ create_shader_description_string(const struct gl_shader_requirements *req)
 	int size;
 	char *str;
 
-	size = asprintf(&str, "%s %s %s %s %s %s %cinput_is_premult %ctint",
+	size = asprintf(&str, "%s %s %s %s %s %cinput_is_premult %ctint",
 			gl_shader_texcoord_input_to_string(req->texcoord_input),
 			gl_shader_texture_variant_to_string(req->variant),
 			gl_shader_color_curve_to_string(req->color_pre_curve),
 			gl_shader_color_mapping_to_string(req->color_mapping),
 			gl_shader_color_curve_to_string(req->color_post_curve),
-			gl_shader_color_order_to_string(req->color_channel_order),
 			req->input_is_premult ? '+' : '-',
 			req->tint ? '+' : '-');
 	if (size < 0)
@@ -272,10 +256,6 @@ create_fragment_shader_config_string(const struct gl_shader_requirements *req)
 	int size;
 	char *str;
 
-	/* EXTERNAL can only be used with identity swizzle */
-	assert(req->variant != SHADER_VARIANT_EXTERNAL ||
-	       req->color_channel_order == SHADER_CHANNEL_ORDER_RGBA);
-
 	size = asprintf(&str,
 			"#define DEF_TINT %s\n"
 			"#define DEF_INPUT_IS_PREMULT %s\n"
@@ -283,7 +263,6 @@ create_fragment_shader_config_string(const struct gl_shader_requirements *req)
 			"#define DEF_COLOR_PRE_CURVE %s\n"
 			"#define DEF_COLOR_MAPPING %s\n"
 			"#define DEF_COLOR_POST_CURVE %s\n"
-			"#define DEF_COLOR_CHANNEL_ORDER %s\n"
 			"#define DEF_VARIANT %s\n",
 			req->tint ? "true" : "false",
 			req->input_is_premult ? "true" : "false",
@@ -291,7 +270,6 @@ create_fragment_shader_config_string(const struct gl_shader_requirements *req)
 			gl_shader_color_curve_to_string(req->color_pre_curve),
 			gl_shader_color_mapping_to_string(req->color_mapping),
 			gl_shader_color_curve_to_string(req->color_post_curve),
-			gl_shader_color_order_to_string(req->color_channel_order),
 			gl_shader_texture_variant_to_string(req->variant));
 	if (size < 0)
 		return NULL;