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I display an image as background for my game.
Now if I display any image or polygon etc its colour is different from what I specified, how to get rid of this problem?
Posted 1-Oct-11 9:21am
Edited 3-Oct-11 8:28am
Santhosh_G at 2-Oct-11 0:07am
How you are displaying image? Texture mappping may cause such isues.

1 solution

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Solution 1

Please check blending is enabled before drawing polygon.
Blending will create an intermediate color of previous image available in framebuffer(background image) and current image.

Please call glDisable( GL_BLEND ) before rendering your polygon and other images.

In texture mapping another tricky thing exists, if you are not specified the texture environment properly, it will consider GL_MODULATE texture environment. The default texture environment is GL_MODULATE, which multiplies the texture color by the primitive (or lighting) color.

For example you are not changed texture environment, and changed color using glColor.

glColor3f( 1.0, 0.0, 0.0 );

// texture mapping code.
// this texture mapping outputs red color and ignores green, and blue channels.

This problem can be solved by providing proper texture environment parameter.

Your problem is not much clear in the question, please provide more information to solve your problem.
Sweety Khan at 4-Oct-11 10:43am
dont know wht was the reason of problem but the problem is solved when i make the fn of tht code n just call it where it is required. btw thanx for telling me about GL_BLEND and GL_MODULATE :)

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