diff options
Diffstat (limited to 'gdk-pixbuf/gdk-pixbuf-util.c')
| -rw-r--r-- | gdk-pixbuf/gdk-pixbuf-util.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/gdk-pixbuf/gdk-pixbuf-util.c b/gdk-pixbuf/gdk-pixbuf-util.c index 848aadd141..db8ca758e5 100644 --- a/gdk-pixbuf/gdk-pixbuf-util.c +++ b/gdk-pixbuf/gdk-pixbuf-util.c @@ -131,3 +131,102 @@ gdk_pixbuf_copy_area (const GdkPixbuf *src_pixbuf, 1.0, 1.0, GDK_INTERP_NEAREST); } + + + +#define INTENSITY(r, g, b) ((r) * 0.30 + (g) * 0.59 + (b) * 0.11) + +/** + * gdk_pixbuf_saturate_and_pixelate: + * @src: source image + * @dest: place to write modified version of @src + * @saturation: saturation factor + * @pixelate: whether to pixelate + * + * Modifies saturation and optionally pixelates @src, placing the + * result in @dest. @src and @dest may be the same pixbuf with no ill + * effects. If @saturation is 1.0 then saturation is not changed. If + * it's less than 1.0, saturation is reduced (the image is darkened); + * if greater than 1.0, saturation is increased (the image is + * brightened). If @pixelate is TRUE, then pixels are faded in a + * checkerboard pattern to create a pixelated image. @src and @dest + * must have the same image format, size, and rowstride. + * + **/ +void +gdk_pixbuf_saturate_and_pixelate(const GdkPixbuf *src, + GdkPixbuf *dest, + gfloat saturation, + gboolean pixelate) +{ + /* NOTE that src and dest MAY be the same pixbuf! */ + + g_return_if_fail (GDK_IS_PIXBUF (src)); + g_return_if_fail (GDK_IS_PIXBUF (dest)); + g_return_if_fail (gdk_pixbuf_get_height (src) == gdk_pixbuf_get_height (dest)); + g_return_if_fail (gdk_pixbuf_get_width (src) == gdk_pixbuf_get_width (dest)); + g_return_if_fail (gdk_pixbuf_get_rowstride (src) == gdk_pixbuf_get_rowstride (dest)); + g_return_if_fail (gdk_pixbuf_get_colorspace (src) == gdk_pixbuf_get_colorspace (dest)); + + if (saturation == 1.0 && !pixelate) { + if (dest != src) + memcpy (gdk_pixbuf_get_pixels (dest), + gdk_pixbuf_get_pixels (src), + gdk_pixbuf_get_height (src) * gdk_pixbuf_get_rowstride (src)); + + return; + } else { + gint i, j; + gint width, height, has_alpha, rowstride; + guchar *target_pixels; + guchar *original_pixels; + guchar *current_pixel; + guchar intensity; + + has_alpha = gdk_pixbuf_get_has_alpha (src); + width = gdk_pixbuf_get_width (src); + height = gdk_pixbuf_get_height (src); + rowstride = gdk_pixbuf_get_rowstride (src); + + target_pixels = gdk_pixbuf_get_pixels (dest); + original_pixels = gdk_pixbuf_get_pixels (src); + + for (i = 0; i < height; i++) { + for (j = 0; j < width; j++) { + current_pixel = original_pixels + i*rowstride + j*(has_alpha?4:3); + intensity = INTENSITY (*(current_pixel), *(current_pixel + 1), *(current_pixel + 2)); + if (pixelate && (i+j)%2 == 0) { + *(target_pixels + i*rowstride + j*(has_alpha?4:3)) = intensity/2 + 127; + *(target_pixels + i*rowstride + j*(has_alpha?4:3) + 1) = intensity/2 + 127; + *(target_pixels + i*rowstride + j*(has_alpha?4:3) + 2) = intensity/2 + 127; + } else if (pixelate) { +#define DARK_FACTOR 0.7 + *(target_pixels + i*rowstride + j*(has_alpha?4:3)) = + (guchar) (((1.0 - saturation) * intensity + + saturation * (*(current_pixel)))) * DARK_FACTOR; + *(target_pixels + i*rowstride + j*(has_alpha?4:3) + 1) = + (guchar) (((1.0 - saturation) * intensity + + saturation * (*(current_pixel + 1)))) * DARK_FACTOR; + *(target_pixels + i*rowstride + j*(has_alpha?4:3) + 2) = + (guchar) (((1.0 - saturation) * intensity + + saturation * (*(current_pixel + 2)))) * DARK_FACTOR; + } else { + *(target_pixels + i*rowstride + j*(has_alpha?4:3)) = + (guchar) ((1.0 - saturation) * intensity + + saturation * (*(current_pixel))); + *(target_pixels + i*rowstride + j*(has_alpha?4:3) + 1) = + (guchar) ((1.0 - saturation) * intensity + + saturation * (*(current_pixel + 1))); + *(target_pixels + i*rowstride + j*(has_alpha?4:3) + 2) = + (guchar) ((1.0 - saturation) * intensity + + saturation * (*(current_pixel + 2))); + } + + if (has_alpha) + *(target_pixels + i*rowstride + j*(has_alpha?4:3) + 3) = *(current_pixel + 3); + } + } + + return; + } +} |