- glReadPixels(0, 0, width, height, format, GL_UNSIGNED_BYTE, out_data);
+ check_error();
+ if (!epoxy_is_desktop_gl() && (format == GL_RED || format == GL_BLUE || format == GL_ALPHA)) {
+ // GLES will only read GL_RGBA.
+ unsigned char *temp = new unsigned char[width * height * 4];
+ glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, temp);
+ check_error();
+ if (format == GL_ALPHA) {
+ for (unsigned i = 0; i < width * height; ++i) {
+ out_data[i] = temp[i * 4 + 3];
+ }
+ } else if (format == GL_BLUE) {
+ for (unsigned i = 0; i < width * height; ++i) {
+ out_data[i] = temp[i * 4 + 2];
+ }
+ } else {
+ for (unsigned i = 0; i < width * height; ++i) {
+ out_data[i] = temp[i * 4];
+ }
+ }
+ delete[] temp;
+ } else {
+ glReadPixels(0, 0, width, height, format, GL_UNSIGNED_BYTE, out_data);
+ check_error();
+ }