libweston: change read_format to struct pixel_format_info

Everywhere we are standardising to drm_fourcc.h pixel format codes, and
using struct pixel_format_info as a general handle that allows us to
access the equivalent format in various APIs. In the name of
standardisation, convert weston_compositor::read_format to
pixel_format_info.

Pixman formats are defined CPU-endian, while DRM formats are defined
always little-endian. OpenGL has various definitions. Correctly mapping
between these when the CPU is big-endian is an extra chore we can
hopefully offload to pixel-formats.c.

GL-renderer read_format is still defined based on Pixman format, because
of the pecualiar way OpenGL defines a pixel format with
GL_UNSIGNED_BYTE. That matches the same Pixman format on big-endian but
not the same drm_fourcc.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>

compositor/screen-share.c

@@ -43,6 +43,7 @@
 #include <libweston/libweston.h>
 #include "backend.h"
 #include "libweston-internal.h"
+#include "pixel-formats.h"
 #include "weston.h"
 #include "shared/helpers.h"
 #include "shared/os-compatibility.h"
@@ -828,8 +829,9 @@ shared_output_repainted(struct wl_listener *listener, void *data)
 	pixman_box32_t *r;
 	pixman_image_t *damaged_image;
 	pixman_transform_t transform;
-	const pixman_format_code_t pixman_format =
+	const struct pixel_format_info *read_format =
 		so->output->compositor->read_format;
+	const pixman_format_code_t pixman_format = read_format->pixman_format;
 
 	width = so->output->current_mode->width;
 	height = so->output->current_mode->height;
@@ -884,7 +886,7 @@ shared_output_repainted(struct wl_listener *listener, void *data)
 			y_orig = y;
 
 		so->output->compositor->renderer->read_pixels(
-			so->output, pixman_format,
+			so->output, read_format,
 			so->tmp_data, x, y_orig, width, height);
 
 		damaged_image = pixman_image_create_bits(pixman_format,

include/libweston/libweston.h

@@ -81,6 +81,7 @@ struct weston_pointer_constraint;
 struct ro_anonymous_file;
 struct weston_color_profile;
 struct weston_color_transform;
+struct pixel_format_info;
 
 enum weston_keyboard_modifier {
 	MODIFIER_CTRL = (1 << 0),
@@ -1252,7 +1253,7 @@ struct weston_compositor {
 
 	struct weston_color_manager *color_manager;
 	struct weston_renderer *renderer;
-	pixman_format_code_t read_format;
+	const struct pixel_format_info *read_format;
 
 	struct weston_backend *backend;
 	struct weston_launcher *launcher;

libweston/libweston-internal.h

@@ -47,7 +47,7 @@
 
 struct weston_renderer {
 	int (*read_pixels)(struct weston_output *output,
-			       pixman_format_code_t format, void *pixels,
+			   const struct pixel_format_info *format, void *pixels,
 			   uint32_t x, uint32_t y,
 			   uint32_t width, uint32_t height);
 	void (*repaint_output)(struct weston_output *output,

libweston/noop-renderer.c

@@ -38,7 +38,7 @@ struct noop_renderer {
 
 static int
 noop_renderer_read_pixels(struct weston_output *output,
-			       pixman_format_code_t format, void *pixels,
+			  const struct pixel_format_info *format, void *pixels,
 			  uint32_t x, uint32_t y,
 			  uint32_t width, uint32_t height)
 {

libweston/pixman-renderer.c

@@ -94,7 +94,7 @@ get_renderer(struct weston_compositor *ec)
 
 static int
 pixman_renderer_read_pixels(struct weston_output *output,
-			       pixman_format_code_t format, void *pixels,
+			    const struct pixel_format_info *format, void *pixels,
 			    uint32_t x, uint32_t y,
 			    uint32_t width, uint32_t height)
 {
@@ -106,11 +106,11 @@ pixman_renderer_read_pixels(struct weston_output *output,
 		return -1;
 	}
 
-	out_buf = pixman_image_create_bits(format,
+	out_buf = pixman_image_create_bits(format->pixman_format,
 		width,
 		height,
 		pixels,
-		(PIXMAN_FORMAT_BPP(format) / 8) * width);
+		(PIXMAN_FORMAT_BPP(format->pixman_format) / 8) * width);
 
 	pixman_image_composite32(PIXMAN_OP_SRC,
 				 po->hw_buffer, /* src */
@@ -914,13 +914,16 @@ pixman_renderer_output_set_buffer(struct weston_output *output,
 				  pixman_image_t *buffer)
 {
 	struct pixman_output_state *po = get_output_state(output);
+	pixman_format_code_t pixman_format;
 
 	if (po->hw_buffer)
 		pixman_image_unref(po->hw_buffer);
 	po->hw_buffer = buffer;
 
 	if (po->hw_buffer) {
-		output->compositor->read_format = pixman_image_get_format(po->hw_buffer);
+		pixman_format = pixman_image_get_format(po->hw_buffer);
+		output->compositor->read_format =
+			pixel_format_get_info_by_pixman(pixman_format);
 		pixman_image_ref(po->hw_buffer);
 	}
 }

libweston/renderer-gl/gl-renderer.c

@@ -1748,7 +1748,7 @@ gl_renderer_repaint_output(struct weston_output *output,
 
 static int
 gl_renderer_read_pixels(struct weston_output *output,
-			pixman_format_code_t format, void *pixels,
+			const struct pixel_format_info *format, void *pixels,
 			uint32_t x, uint32_t y,
 			uint32_t width, uint32_t height)
 {
@@ -1758,7 +1758,7 @@ gl_renderer_read_pixels(struct weston_output *output,
 	x += go->borders[GL_RENDERER_BORDER_LEFT].width;
 	y += go->borders[GL_RENDERER_BORDER_BOTTOM].height;
 
-	switch (format) {
+	switch (format->pixman_format) {
 	case PIXMAN_a8r8g8b8:
 		gl_format = GL_BGRA_EXT;
 		break;
@@ -3883,9 +3883,9 @@ gl_renderer_setup(struct weston_compositor *ec, EGLSurface egl_surface)
 	}
 
 	if (weston_check_egl_extension(extensions, "GL_EXT_read_format_bgra"))
-		ec->read_format = PIXMAN_a8r8g8b8;
+		ec->read_format = pixel_format_get_info_by_pixman(PIXMAN_a8r8g8b8);
 	else
-		ec->read_format = PIXMAN_a8b8g8r8;
+		ec->read_format = pixel_format_get_info_by_pixman(PIXMAN_a8b8g8r8);
 
 	if (gr->gl_version < gr_gl_version(3, 0) &&
 	    !weston_check_egl_extension(extensions, "GL_EXT_unpack_subimage")) {
@@ -3935,7 +3935,7 @@ gl_renderer_setup(struct weston_compositor *ec, EGLSurface egl_surface)
 		   gr_gl_version_major(gr->gl_version),
 		   gr_gl_version_minor(gr->gl_version));
 	weston_log_continue(STAMP_SPACE "read-back format: %s\n",
-			    ec->read_format == PIXMAN_a8r8g8b8 ? "BGRA" : "RGBA");
+			    ec->read_format->drm_format_name);
 	weston_log_continue(STAMP_SPACE "wl_shm 10 bpc formats: %s\n",
 			    yesno(gr->has_texture_type_2_10_10_10_rev));
 	weston_log_continue(STAMP_SPACE "wl_shm 16 bpc formats: %s\n",

libweston/screenshooter.c

@@ -40,6 +40,7 @@
 #include "shared/timespec-util.h"
 #include "backend.h"
 #include "libweston-internal.h"
+#include "pixel-formats.h"
 
 #include "wcap/wcap-decode.h"
 
@@ -122,12 +123,14 @@ screenshooter_frame_notify(struct wl_listener *listener, void *data)
 			     struct screenshooter_frame_listener, listener);
 	struct weston_output *output = l->output;
 	struct weston_compositor *compositor = output->compositor;
+	const pixman_format_code_t pixman_format =
+		compositor->read_format->pixman_format;
 	int32_t stride;
 	uint8_t *pixels, *d, *s;
 
 	weston_output_disable_planes_decr(output);
 	wl_list_remove(&listener->link);
-	stride = l->buffer->width * (PIXMAN_FORMAT_BPP(compositor->read_format) / 8);
+	stride = l->buffer->width * (PIXMAN_FORMAT_BPP(pixman_format) / 8);
 	pixels = malloc(stride * l->buffer->height);
 
 	if (pixels == NULL) {
@@ -148,7 +151,7 @@ screenshooter_frame_notify(struct wl_listener *listener, void *data)
 
 	wl_shm_buffer_begin_access(l->buffer->shm_buffer);
 
-	switch (compositor->read_format) {
+	switch (pixman_format) {
 	case PIXMAN_a8r8g8b8:
 	case PIXMAN_x8r8g8b8:
 		if (compositor->capabilities & WESTON_CAP_CAPTURE_YFLIP)
@@ -414,7 +417,7 @@ weston_recorder_create(struct weston_output *output, const char *filename)
 
 	header.magic = WCAP_HEADER_MAGIC;
 
-	switch (compositor->read_format) {
+	switch (compositor->read_format->pixman_format) {
 	case PIXMAN_x8r8g8b8:
 	case PIXMAN_a8r8g8b8:
 		header.format = WCAP_FORMAT_XRGB8888;