View Full Version : RGB
01-01-2004, 08:55 PM
In my machine when I am using RGBA(8-8-8-8), the h/w acceleration is not supported. Where as when I use RGBA(8-8-8-0) the h/w acceleration is supported and my application runs very very fast. But I want to display the RGB image in transparent on the screen without using RGBA. Means I can choose one color as a Transparent color in RGB image. Is it possible to display transparent RGBs without RGBA.
01-01-2004, 11:45 PM
You don't need framebuffer alpha to display transparent textures. Look into glblendFunc and glAlphaFunc.
01-05-2004, 01:59 AM
I want to display one .BMP image on the screen. I am using RGB(8-8-8-0) Mode. My image cotains BLACK color as the background color. And I want to display the image excluding this BLACK color. What is the Blend function for this one. Presently I am using
[This message has been edited by ramana (edited 01-05-2004).]
01-05-2004, 02:18 AM
That is the correct blend function. But you don't even need a blend function for your case, you still need alpha though.
Try using alpha testing and no blending for faster results on many platforms.
This should be fast even in software although I suspect your problem may be that you're using glDrawPixels and so you'd need to draw your image using texture for an optimized path.
Try loading the image as a texture and drawing on a quad with a GL_REPLACE texture environment, drawpixels is not very fast on some implementations, especially if you do things like blend pixels. If you're running in software when you use texture also use a GL_NEAREST texture filter for min & max, this texture path is definitely optimized for software rendering in the fallback libs.
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