* @height: Height of region to threshold.
* @alpha_threshold: Opacity values below this will be painted as zero; all
* other values will be painted as one.
- *
- * Takes the opacity values in a pixbuf and thresholds them to produce a
- * bi-level alpha mask that can be used as a clipping mask for a drawable.
+ *
+ * Takes the opacity values in a rectangular portion of a pixbuf and thresholds
+ * them to produce a bi-level alpha mask that can be used as a clipping mask for
+ * a drawable.
**/
void
gdk_pixbuf_render_threshold_alpha (GdkPixbuf *pixbuf, GdkBitmap *bitmap,
gdk_gc_unref (gc);
}
+\f
+
+/* Creates a buffer by stripping the alpha channel of a pixbuf */
+static guchar *
+remove_alpha (ArtPixBuf *apb, int x, int y, int width, int height, int *rowstride)
+{
+ guchar *buf;
+ int xx, yy;
+ guchar *src, *dest;
+
+ g_assert (apb->n_channels == 4);
+ g_assert (apb->has_alpha);
+ g_assert (x >= 0 && x + width <= apb->width);
+ g_assert (y >= 0 && y + height <= apb->height);
+
+ *rowstride = 4 * ((width * 3 + 3) / 4);
+
+ buf = g_new (guchar, *rowstride * height);
+
+ for (yy = 0; yy < height; yy++) {
+ src = apb->pixels + apb->rowstride * (yy + y) + x * apb->n_channels;
+ dest = buf + *rowstride * yy;
+
+ for (xx = 0; xx < width; xx++) {
+ *dest++ = *src++;
+ *dest++ = *src++;
+ *dest++ = *src++;
+ src++;
+ }
+ }
+
+ return buf;
+}
+
+/**
+ * gdk_pixbuf_render_to_drawable:
+ * @pixbuf: A pixbuf.
+ * @drawable: Destination drawable.
+ * @gc: GC used for rendering.
+ * @src_x: Source X coordinate within pixbuf.
+ * @src_y: Source Y coordinate within pixbuf.
+ * @dest_x: Destination X coordinate within drawable.
+ * @dest_y: Destination Y coordinate within drawable.
+ * @width: Width of region to render, in pixels.
+ * @height: Height of region to render, in pixels.
+ * @dither: Dithering mode for GdkRGB.
+ * @x_dither: X offset for dither.
+ * @y_dither: Y offset for dither.
+ *
+ * Renders a rectangular portion of a pixbuf to a drawable while using the
+ * specified GC. This is done using GdkRGB, so the specified drawable must have
+ * the GdkRGB visual and colormap. Note that this function will ignore the
+ * opacity information for images with an alpha channel; the GC must already
+ * have the clipping mask set if you want transparent regions to show through.
+ **/
void
-gdk_pixbuf_render_to_drawable (GdkPixbuf *pixbuf, GdkDrawable *drawable,
+gdk_pixbuf_render_to_drawable (GdkPixbuf *pixbuf,
+ GdkDrawable *drawable, GdkGC *gc,
int src_x, int src_y,
int dest_x, int dest_y,
int width, int height,
- GdkPixbufAlphaMode alpha_mode,
- int alpha_threshold,
GdkRgbDither dither,
int x_dither, int y_dither)
{
ArtPixBuf *apb;
- ArtIRect dest_rect, req_rect, area_rect;
- GdkBitmap *bitmap;
- GdkGC *gc;
guchar *buf;
int rowstride;
+ g_return_if_fail (pixbuf != NULL);
+ apb = pixbuf->art_pixbuf;
+
+ g_return_if_fail (apb->format == ART_PIX_RGB);
+ g_return_if_fail (apb->n_channels == 3 || apb->n_channels == 4);
+ g_return_if_fail (apb->bits_per_sample == 8);
+
+ g_return_if_fail (drawable != NULL);
+ g_return_if_fail (gc != NULL);
+
+ g_return_if_fail (src_x >= 0 && src_x + width <= apb->width);
+ g_return_if_fail (src_y >= 0 && src_y + height <= apb->height);
+
+ /* This will have to be modified once libart supports other image types.
+ * Also, GdkRGB does not have gdk_draw_rgb_32_image_dithalign(), so we
+ * have to pack the buffer first.
+ */
+
+ if (apb->has_alpha)
+ buf = remove_alpha (apb, src_x, src_y, width, height, &rowstride);
+ else {
+ buf = apb->pixels + src_y * apb->rowstride + src_x * 3;
+ rowstride = apb->rowstride;
+ }
+
+ gdk_draw_rgb_image_dithalign (drawable, gc,
+ dest_x, dest_y,
+ width, height,
+ dither,
+ buf, rowstride,
+ x_dither, y_dither);
+
+ if (apb->has_alpha)
+ g_free (buf);
+}
+
+\f
+
+/**
+ * gdk_pixbuf_render_to_drawable_alpha:
+ * @pixbuf: A pixbuf.
+ * @drawable: Destination drawable.
+ * @src_x: Source X coordinate within pixbuf.
+ * @src_y: Source Y coordinates within pixbuf.
+ * @dest_x: Destination X coordinate within drawable.
+ * @dest_y: Destination Y coordinate within drawable.
+ * @width: Width of region to render, in pixels.
+ * @height: Height of region to render, in pixels.
+ * @alpha_mode: If the image does not have opacity information, this is ignored.
+ * Otherwise, specifies how to handle transparency when rendering.
+ * @alpha_threshold: If the image does have opacity information and @alpha_mode
+ * is GDK_PIXBUF_ALPHA_BILEVEL, specifies the threshold value for opacity
+ * values.
+ * @dither: Dithering mode for GdkRGB.
+ * @x_dither: X offset for dither.
+ * @y_dither: Y offset for dither.
+ *
+ * Renders a rectangular portion of a pixbuf to a drawable. This is done using
+ * GdkRGB, so the specified drawable must have the GdkRGB visual and colormap.
+ **/
+void
+gdk_pixbuf_render_to_drawable_alpha (GdkPixbuf *pixbuf, GdkDrawable *drawable,
+ int src_x, int src_y,
+ int dest_x, int dest_y,
+ int width, int height,
+ GdkPixbufAlphaMode alpha_mode,
+ int alpha_threshold,
+ GdkRgbDither dither,
+ int x_dither, int y_dither)
+{
+ ArtPixBuf *apb;
+ GdkBitmap *bitmap;
+ GdkGC *gc;
+
g_return_if_fail (pixbuf != NULL);
apb = pixbuf->art_pixbuf;
gdk_gc_set_clip_mask (gc, bitmap);
gdk_gc_set_clip_origin (gc, dest_x, dest_y);
+ gdk_bitmap_unref (bitmap);
}
- /* Sigh, GdkRGB does not have gdk_draw_rgb_32_image_dithalign(), so we
- * have to pack the buffer first.
- */
- if (apb->has_alpha) {
-// buf = remove_alpha (apb, src_x, src_y, width, height, &rowstride);
- } else {
- buf = apb->pixels + src_y * apb->rowstride + src_x * 3;
- rowstride = apb->rowstride;
- }
+ gdk_pixbuf_render_to_drawable (pixbuf, drawable, gc,
+ src_x, src_y,
+ dest_x, dest_y,
+ width, height,
+ dither,
+ x_dither, y_dither);
+
+ gdk_gc_unref (gc);
}
projects / gtk4.git / commitdiff