[cairo] patch [1/1] invert image in _cairo_gl_surrface_map_to_image

[Henry Song]

    gl: Add support to invert non texture gl surface image that does not
have
    GL_MESA_pack_invert when map from gl surface to image surface

diff --git a/src/cairo-gl-surface.c b/src/cairo-gl-surface.c
index 8f69033..8b8f196 100644

--- a/src/cairo-gl-surface.c
+++ b/src/cairo-gl-surface.c
@@ -1001,6 +1001,10 @@ _cairo_gl_surface_map_to_image (void
*abstract_surface,
     unsigned int cpp;
     cairo_bool_t invert;
     cairo_status_t status;
+    cairo_t *inv_cr = NULL;
+    cairo_image_surface_t *inv_image = NULL;
+    cairo_pattern_t *inv_pattern = NULL;
+    cairo_matrix_t inv_matrix;
 
     /* Want to use a switch statement here but the compiler gets whiny. */
     if (surface->base.content == CAIRO_CONTENT_COLOR_ALPHA) {
@@ -1093,6 +1097,50 @@ _cairo_gl_surface_map_to_image (void
*abstract_surface,
 	image = (cairo_image_surface_t *)
 	    _cairo_surface_create_in_error (status);
     }
+    
+    /* 
+     * FIXME: we must invert the image if it is non texture surface,
+     * and it does not have GL_MESA_pack_invert.
+     * Is there more efficient way to invert image? 
+     */
+
+    if (! _cairo_gl_surface_is_texture (surface) && ! invert) {
+        inv_image = (cairo_image_surface_t*)
+	_cairo_image_surface_create_with_pixman_format (NULL,
+							pixman_format,
+							extents->width,
+							extents->height,
+							-1);
+	if (unlikely (inv_image->base.status)) {
+	    goto CLEAR_IMAGE;
+	}
+
+	image->base.is_clear = FALSE;
+	inv_pattern = cairo_pattern_create_for_surface (&image->base);
+	if (unlikely (inv_pattern->status)) {
+	    goto CLEAR_PATTERN;
+	}
+	cairo_matrix_init_scale (&inv_matrix, 1.0, -1.0);
+	cairo_matrix_translate (&inv_matrix, 0, -(extents->height));
+	cairo_pattern_set_matrix (inv_pattern, &inv_matrix);
+
+	inv_cr = cairo_create (&inv_image->base);
+	if (unlikely (inv_cr->status)) {
+	    goto CLEAR_CAIRO;
+	}
+	cairo_set_source (inv_cr, inv_pattern);
+	cairo_set_operator (inv_cr, CAIRO_OPERATOR_SOURCE);
+	cairo_paint (inv_cr);
+	cairo_surface_destroy (&image->base);
+	image = (cairo_image_surface_t *)cairo_surface_reference
(&inv_image->base);
+    }
+
+CLEAR_CAIRO:
+    cairo_destroy (inv_cr);
+CLEAR_PATTERN:
+    cairo_pattern_destroy (inv_pattern);
+CLEAR_IMAGE:
+    cairo_surface_destroy (&inv_image->base);
 
     return &image->base;
 }