compositor: make GL_EXT_read_format_bgra optional
Some GL implementations do not provide GL_EXT_read_format_bgra
extension.
Set a glReadPixels format based on whether the extensions is supported
or not, and use that format in all backends.
Add RGBA->BGRA swapping copy to screenshooter to keep the shm buffer
data format as BGRA.
Signed-off-by: Pekka Paalanen <ppaalanen@gmail.com>
diff --git a/src/screenshooter.c b/src/screenshooter.c
index 835e175..b4b341b 100644
--- a/src/screenshooter.c
+++ b/src/screenshooter.c
@@ -51,6 +51,37 @@
}
static void
+copy_row_swap_RB(void *vdst, void *vsrc, int bytes)
+{
+ uint32_t *dst = vdst;
+ uint32_t *src = vsrc;
+ uint32_t *end = dst + bytes / 4;
+
+ while (dst < end) {
+ uint32_t v = *src++;
+ /* A R G B */
+ uint32_t tmp = v & 0xff00ff00;
+ tmp |= (v >> 16) & 0x000000ff;
+ tmp |= (v << 16) & 0x00ff0000;
+ *dst++ = tmp;
+ }
+}
+
+static void
+copy_rgba_yflip(uint8_t *dst, uint8_t *src, int height,
+ int dst_stride, int src_stride)
+{
+ uint8_t *end;
+
+ end = dst + height * dst_stride;
+ while (dst < end) {
+ copy_row_swap_RB(dst, src, src_stride);
+ dst += dst_stride;
+ src -= src_stride;
+ }
+}
+
+static void
screenshooter_shoot(struct wl_client *client,
struct wl_resource *resource,
struct wl_resource *output_resource,
@@ -82,8 +113,19 @@
d = wl_shm_buffer_get_data(buffer) + output->y * buffer_stride +
output->x * 4;
s = tmp + output_stride * (output->current->height - 1);
- copy_bgra_yflip(d, s, output->current->height,
- buffer_stride, output_stride);
+
+ switch (output->compositor->read_format) {
+ case GL_BGRA_EXT:
+ copy_bgra_yflip(d, s, output->current->height,
+ buffer_stride, output_stride);
+ break;
+ case GL_RGBA:
+ copy_rgba_yflip(d, s, output->current->height,
+ buffer_stride, output_stride);
+ break;
+ default:
+ break;
+ }
free(tmp);
}