aboutsummaryrefslogtreecommitdiffstats
path: root/common/cairo.c
diff options
context:
space:
mode:
Diffstat (limited to 'common/cairo.c')
-rw-r--r--common/cairo.c99
1 files changed, 0 insertions, 99 deletions
diff --git a/common/cairo.c b/common/cairo.c
index f2ad54c1..403dcf49 100644
--- a/common/cairo.c
+++ b/common/cairo.c
@@ -1,9 +1,6 @@
1#include <stdint.h> 1#include <stdint.h>
2#include <cairo/cairo.h> 2#include <cairo/cairo.h>
3#include "cairo.h" 3#include "cairo.h"
4#if HAVE_GDK_PIXBUF
5#include <gdk-pixbuf/gdk-pixbuf.h>
6#endif
7 4
8void cairo_set_source_u32(cairo_t *cairo, uint32_t color) { 5void cairo_set_source_u32(cairo_t *cairo, uint32_t color) {
9 cairo_set_source_rgba(cairo, 6 cairo_set_source_rgba(cairo,
@@ -45,99 +42,3 @@ cairo_surface_t *cairo_image_surface_scale(cairo_surface_t *image,
45 cairo_destroy(cairo); 42 cairo_destroy(cairo);
46 return new; 43 return new;
47} 44}
48
49#if HAVE_GDK_PIXBUF
50cairo_surface_t* gdk_cairo_image_surface_create_from_pixbuf(const GdkPixbuf *gdkbuf) {
51 int chan = gdk_pixbuf_get_n_channels(gdkbuf);
52 if (chan < 3) {
53 return NULL;
54 }
55
56 const guint8* gdkpix = gdk_pixbuf_read_pixels(gdkbuf);
57 if (!gdkpix) {
58 return NULL;
59 }
60 gint w = gdk_pixbuf_get_width(gdkbuf);
61 gint h = gdk_pixbuf_get_height(gdkbuf);
62 int stride = gdk_pixbuf_get_rowstride(gdkbuf);
63
64 cairo_format_t fmt = (chan == 3) ? CAIRO_FORMAT_RGB24 : CAIRO_FORMAT_ARGB32;
65 cairo_surface_t * cs = cairo_image_surface_create (fmt, w, h);
66 cairo_surface_flush (cs);
67 if ( !cs || cairo_surface_status(cs) != CAIRO_STATUS_SUCCESS) {
68 return NULL;
69 }
70
71 int cstride = cairo_image_surface_get_stride(cs);
72 unsigned char * cpix = cairo_image_surface_get_data(cs);
73
74 if (chan == 3) {
75 int i;
76 for (i = h; i; --i) {
77 const guint8 *gp = gdkpix;
78 unsigned char *cp = cpix;
79 const guint8* end = gp + 3*w;
80 while (gp < end) {
81#if G_BYTE_ORDER == G_LITTLE_ENDIAN
82 cp[0] = gp[2];
83 cp[1] = gp[1];
84 cp[2] = gp[0];
85#else
86 cp[1] = gp[0];
87 cp[2] = gp[1];
88 cp[3] = gp[2];
89#endif
90 gp += 3;
91 cp += 4;
92 }
93 gdkpix += stride;
94 cpix += cstride;
95 }
96 } else {
97 /* premul-color = alpha/255 * color/255 * 255 = (alpha*color)/255
98 * (z/255) = z/256 * 256/255 = z/256 (1 + 1/255)
99 * = z/256 + (z/256)/255 = (z + z/255)/256
100 * # recurse once
101 * = (z + (z + z/255)/256)/256
102 * = (z + z/256 + z/256/255) / 256
103 * # only use 16bit uint operations, loose some precision,
104 * # result is floored.
105 * -> (z + z>>8)>>8
106 * # add 0x80/255 = 0.5 to convert floor to round
107 * => (z+0x80 + (z+0x80)>>8 ) >> 8
108 * ------
109 * tested as equal to lround(z/255.0) for uint z in [0..0xfe02]
110 */
111#define PREMUL_ALPHA(x,a,b,z) \
112 G_STMT_START { z = a * b + 0x80; x = (z + (z >> 8)) >> 8; } \
113 G_STMT_END
114 int i;
115 for (i = h; i; --i) {
116 const guint8 *gp = gdkpix;
117 unsigned char *cp = cpix;
118 const guint8* end = gp + 4*w;
119 guint z1, z2, z3;
120 while (gp < end) {
121#if G_BYTE_ORDER == G_LITTLE_ENDIAN
122 PREMUL_ALPHA(cp[0], gp[2], gp[3], z1);
123 PREMUL_ALPHA(cp[1], gp[1], gp[3], z2);
124 PREMUL_ALPHA(cp[2], gp[0], gp[3], z3);
125 cp[3] = gp[3];
126#else
127 PREMUL_ALPHA(cp[1], gp[0], gp[3], z1);
128 PREMUL_ALPHA(cp[2], gp[1], gp[3], z2);
129 PREMUL_ALPHA(cp[3], gp[2], gp[3], z3);
130 cp[0] = gp[3];
131#endif
132 gp += 4;
133 cp += 4;
134 }
135 gdkpix += stride;
136 cpix += cstride;
137 }
138#undef PREMUL_ALPHA
139 }
140 cairo_surface_mark_dirty(cs);
141 return cs;
142}
143#endif // HAVE_GDK_PIXBUF