changing texture colors

Graphics and GPU Programming Programming OpenGL

Started by redb June 05, 2011 09:23 AM

2 comments, last by dpadam450 12 years, 10 months ago

100

Author

June 05, 2011 09:23 AM

I am using SDL/Opengl in a game project, I am using textures with specific colors that I wish change to another ( on user choice, eg, replacing grey section by green color, blue section by red, etc .. )

My first solution was to load a SDL_Surface and changing every pixel from one color to another, but that is not really fast, is it possible to do a dynamic color change in a texture with opengl ?

V-man

813

June 05, 2011 05:16 PM

One way is to use a lookup table which is actually a texture.
http://www.opengl.org/wiki/Common_Mistakes#Paletted_textures

Sig: http://glhlib.sourceforge.net
an open source GLU replacement library. Much more modern than GLU.
float matrix[16], inverse_matrix[16];
glhLoadIdentityf2(matrix);
glhTranslatef2(matrix, 0.0, 0.0, 5.0);
glhRotateAboutXf2(matrix, angleInRadians);
glhScalef2(matrix, 1.0, 1.0, -1.0);
glhQuickInvertMatrixf2(matrix, inverse_matrix);
glUniformMatrix4fv(uniformLocation1, 1, FALSE, matrix);
glUniformMatrix4fv(uniformLocation2, 1, FALSE, inverse_matrix);

redb

100

Author

June 07, 2011 12:24 PM

Ok thanks, I this the best and smipler way is to use a shader..

dpadam450

2,403

June 07, 2011 11:01 PM

If your doing something like team color markings, you can make a 2nd texture that overlays your actual texture with all white and alpha (or just an intensity from 0 to 1). Where 1 or white is where you want team color markings to show up. Then you can just send a color to the shader and it will be something like:

glFragColor = baseTexture.rgba + colorOutlineTexture.a*glColor;

NBA2K, Madden, Maneater, Killing Floor, Sims http://www.pawlowskipinball.com/pinballeternal

changing texture colors

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

changing texture colors

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

Reticulating splines