Question

Do I have to set up my gl context in a certain way to bind textures. I’m following a tutorial. I start by doing:

#define checkImageWidth 64
#define checkImageHeight 64
static GLubyte checkImage[checkImageHeight][checkImageWidth][4];

static GLuint texName;

void makeCheckImage(void)
{
    int i, j, c;

    for (i = 0; i < checkImageHeight; i++) {
        for (j = 0; j < checkImageWidth; j++) {
            c = ((((i&0x8)==0)^((j&0x8))==0))*255;
            checkImage[i][j][0] = (GLubyte) c;
            checkImage[i][j][1] = (GLubyte) c;
            checkImage[i][j][2] = (GLubyte) c;
            checkImage[i][j][3] = (GLubyte) 255;
        }
    }
}


void initt(void)
{    
    glClearColor (0.0, 0.0, 0.0, 0.0);


    makeCheckImage();
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

    glGenTextures(1, &texName);
    glBindTexture(GL_TEXTURE_2D, texName);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, 
        GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, 
        GL_NEAREST);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, checkImageWidth, 
        checkImageHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, 
        checkImage);
    engineGL.current.tex = texName;
}

In my rendering I do:

PolygonTesselator.Begin_Contour();
            glEnable(GL_TEXTURE_2D);
                glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
                glBindTexture(GL_TEXTURE_2D, current.tex);

        if(layer[currentlayer].Shapes[i].Contour[c].DrawingPoints.size() > 0)
        {
            glColor4f(
                layer[currentlayer].Shapes[i].Color.r,
                layer[currentlayer].Shapes[i].Color.g,
                layer[currentlayer].Shapes[i].Color.b,
                layer[currentlayer].Shapes[i].Color.a);


        }

        for(unsigned int j = 0; j < layer[currentlayer].Shapes[i].Contour[c].DrawingPoints.size(); ++j)
        {
            gluTessVertex(PolygonTesselator.tobj,&layer[currentlayer].Shapes[i].Contour[c].DrawingPoints[j][0],
                &layer[currentlayer].Shapes[i].Contour[c].DrawingPoints[j][0]);
        }

        PolygonTesselator.End_Contour();
            }
            glDisable(GL_TEXTURE_2D);
    }

However it still renders the color and not the texture at all. I’d atleast expect to see black or something but its as if the bind fails. Am I missing something?

Thanks

Answer 1

It looks like from that code that you don’t set any UVs.

Edit: Does it make any difference using GL_MODULATE instead of GL_DECAL? (Am taking guesses here because I suspect the problem lies in code you haven’t provided, or in gluTessVertex itself …