cairo-util: Dont use non-standard JCS_EXT_BGRX color space
Everytime somebody has to write a channel swizzling loop,
God kills a kitten... and a dolphin and a unicorn.
diff --git a/clients/cairo-util.c b/clients/cairo-util.c
index 61a053b..54a05b1 100644
--- a/clients/cairo-util.c
+++ b/clients/cairo-util.c
@@ -289,13 +289,28 @@
cairo_close_path(cr);
}
+static void
+swizzle_row(JSAMPLE *row, JDIMENSION width)
+{
+ JSAMPLE *s;
+ uint32_t *d;
+
+ s = row + (width - 1) * 3;
+ d = (uint32_t *) (row + (width - 1) * 4);
+ while (s >= row) {
+ *d = 0xff000000 | (s[0] << 16) | (s[1] << 8) | (s[2] << 0);
+ s -= 3;
+ d--;
+ }
+}
+
cairo_surface_t *
load_jpeg(const char *filename)
{
struct jpeg_decompress_struct cinfo;
struct jpeg_error_mgr jerr;
FILE *fp;
- int stride, i;
+ int stride, i, first;
JSAMPLE *data, *rows[4];
cinfo.err = jpeg_std_error(&jerr);
@@ -310,7 +325,7 @@
jpeg_read_header(&cinfo, TRUE);
- cinfo.out_color_space = JCS_EXT_BGRX;
+ cinfo.out_color_space = JCS_RGB;
jpeg_start_decompress(&cinfo);
stride = cairo_format_stride_for_width(CAIRO_FORMAT_RGB24,
@@ -322,10 +337,13 @@
}
while (cinfo.output_scanline < cinfo.output_height) {
+ first = cinfo.output_scanline;
for (i = 0; i < ARRAY_LENGTH(rows); i++)
- rows[i] = data + (cinfo.output_scanline + i) * stride;
+ rows[i] = data + (first + i) * stride;
jpeg_read_scanlines(&cinfo, rows, ARRAY_LENGTH(rows));
+ for (i = 0; first + i < cinfo.output_scanline; i++)
+ swizzle_row(rows[i], cinfo.output_width);
}
jpeg_finish_decompress(&cinfo);