demos/gtk-utils.c

   1 #include <gtk/gtk.h>
   2 #include <config.h>
   3 #include "pixman-private.h"     /* For image->bits.format
   4                                  * FIXME: there should probably be public API for this
   5                                  */
   6 #include "gtk-utils.h"
   7
   8 GdkPixbuf *
   9 pixbuf_from_argb32 (uint32_t *bits,
  10                     gboolean has_alpha,
  11                     int width,
  12                     int height,
  13                     int stride)
  14 {
  15     GdkPixbuf *pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB, TRUE,
  16                                         8, width, height);
  17     int p_stride = gdk_pixbuf_get_rowstride (pixbuf);
  18     guint32 *p_bits = (guint32 *)gdk_pixbuf_get_pixels (pixbuf);
  19     int w, h;
  20
  21     for (h = 0; h < height; ++h)
  22     {
  23         for (w = 0; w < width; ++w)
  24         {
  25             uint32_t argb = bits[h * (stride / 4) + w];
  26             guint r, g, b, a;
  27             char *pb = (char *)p_bits;
  28
  29             pb += h * p_stride + w * 4;
  30
  31             r = (argb & 0x00ff0000) >> 16;
  32             g = (argb & 0x0000ff00) >> 8;
  33             b = (argb & 0x000000ff) >> 0;
  34             a = has_alpha? (argb & 0xff000000) >> 24 : 0xff;
  35
  36             if (a)
  37             {
  38                 r = (r * 255) / a;
  39                 g = (g * 255) / a;
  40                 b = (b * 255) / a;
  41             }
  42
  43             if (r > 255) r = 255;
  44             if (g > 255) g = 255;
  45             if (b > 255) b = 255;
  46
  47             pb[0] = r;
  48             pb[1] = g;
  49             pb[2] = b;
  50             pb[3] = a;
  51         }
  52     }
  53
  54     return pixbuf;
  55 }
  56
  57
  58 static gboolean
  59 on_expose (GtkWidget *widget, GdkEventExpose *expose, gpointer data)
  60 {
  61     GdkPixbuf *pixbuf = data;
  62
  63     gdk_draw_pixbuf (widget->window, NULL,
  64                      pixbuf, 0, 0, 0, 0,
  65                      gdk_pixbuf_get_width (pixbuf),
  66                      gdk_pixbuf_get_height (pixbuf),
  67                      GDK_RGB_DITHER_NONE,
  68                      0, 0);
  69
  70     return TRUE;
  71 }
  72
  73 void
  74 show_image (pixman_image_t *image)
  75 {
  76     GtkWidget *window;
  77     GdkPixbuf *pixbuf;
  78     int width, height, stride;
  79     int argc;
  80     char **argv;
  81     char *arg0 = g_strdup ("pixman-test-program");
  82     gboolean has_alpha;
  83     pixman_format_code_t format;
  84
  85     argc = 1;
  86     argv = (char **)&arg0;
  87
  88     gtk_init (&argc, &argv);
  89
  90     window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
  91     width = pixman_image_get_width (image);
  92     height = pixman_image_get_height (image);
  93     stride = pixman_image_get_stride (image);
  94
  95     gtk_window_set_default_size (GTK_WINDOW (window), width, height);
  96
  97     format = image->bits.format;
  98
  99     if (format == PIXMAN_a8r8g8b8)
 100         has_alpha = TRUE;
 101     else if (format == PIXMAN_x8r8g8b8)
 102         has_alpha = FALSE;
 103     else
 104         g_error ("Can't deal with this format: %x\n", format);
 105
 106     pixbuf = pixbuf_from_argb32 (pixman_image_get_data (image), has_alpha,
 107                                  width, height, stride);
 108
 109     g_signal_connect (window, "expose_event", G_CALLBACK (on_expose), pixbuf);
 110     g_signal_connect (window, "delete_event", G_CALLBACK (gtk_main_quit), NULL);
 111
 112     gtk_widget_show (window);
 113
 114     gtk_main ();
 115 }