Hello.
I'm writing an editor in GTK that uses textures in opengl. I want current texture to be shown in GtkImage widget. This is what I do:
void set_current_image_tex()
{
GdkVisual *visual = gdk_visual_get_best();
ETexture *t = getDocument()->getTexture(selected_texture);
if (t) {
Image &img = t->img;
GdkImage *image = gdk_image_new(GDK_IMAGE_NORMAL, visual, img.getWidth(),img.getHeight());
for (int x=0; x<img.getWidth(); x++)
for (int y=0; y<img.getHeight(); y++)
{
uint value = img.getPixel(x,y);
uchar red = uint2red(value);
uchar green = uint2green(value);
uchar blue = uint2blue(value);
gdk_image_put_pixel(image,x,y, pixel_from_rgb(visual, red, green, blue));
}
// set new image to GtkImage widget
gtk_image_set(GTK_IMAGE(image_tex),image,0);
}
}
// And the pixel_from_rgb I found from DevHelp
guint pixel_from_rgb (GdkVisual *visual, guchar r, guchar b, guchar g)
{
return ((r >> (16 - visual->red_prec)) << visual->red_shift) |
((g >> (16 - visual->green_prec)) << visual->green_shift) |
((r >> (16 - visual->blue_prec)) << visual->blue_shift);
}
The problem is that this doesnt work. The image is always black. I don't know how to get right visual (I get the best).
I can get it to work if I use these (I tried):
guint pixel_from_rgb (GdkVisual *visual, guchar r, guchar b, guchar g)
{
// This works on my Linux desktop (32 bit display)
return rgb2uint(g,b,r);
// And this on Windows with Voodoo3 (16 bit display)
return (g>>3) | ((b>>2)<<5) | ((r>>3)<<11);
My question is how to write a pixel_from_rgb that works in all cases? What visual to get? Should it be same as is the graphics mode?
Thanks.
[edited by - stefu on December 21, 2002 7:21:07 AM]
