Question

My assignment is to get “images read into pixmaps which you will then convert to texture maps”. So for the pixmap part only, hear me out and tell me if I have the right idea and if there’s an easier way. Library docs I’m using: http://www.imagemagick.org/Magick++/Documentation.html

Read in image:

Image myimage;
myimage.read( "myimage.gif" );

I think this is the pixmap I need to read ‘image’ into:

GLubyte pixmap[TextureSize][TextureSize][3];

So I think I need a loop that, for every ‘pixmap’ pixel index, assigns R,G,B values from the corresponding ‘image’ pixel indices. I’m thinking the loop body is like this:

pixmap[i][j][0] = myimage.pixelColor(i,j).redQuantum(void);
pixmap[i][j][1] = myimage.pixelColor(i,j).greenQuantum(void);
pixmap[i][j][2] = myimage.pixelColor(i,j).blueQuantum(void);

But I think the above functions return Quantums where I need GLubytes, so can anyone offer help here?

— OR —

Perhaps I can take care of both the pixmap and texture map by using OpenIL (docs here: http://openil.sourceforge.net/tuts/tut_10/index.htm). Think I could simply call these in sequence?

ilutOglLoadImage(char *FileName);
ilutOglBindTexImage(ILvoid);

Answer 1

You can copy the quantum values returned by pixelColor(x,y) to ColorRGB and you will get normalized (0.0,1.0) color values.

If you don’t have to stick with Magick++ maybe you can try OpenIL, which can load and convert your image to OpenGL texture maps without too much hassle.