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Fantastic Jason

Display Lists...Aaarrrhhhhh

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Hi everyone, Having a little trouble with creating a display list: The display list should display a tiled map which s 20 tiles wide x 12 tiles the code below feasible as nothing is displayed when the list is called......what am I doing wrong?
    MapList=glGenLists(1); // We are going to start off with one list for map
        // All that goes into our display list goes here
        for(int x=0;x<20;x++)
            for(int y=0;y<12;y++)  
                // Get the tile number from the array
    		int Tile = Maps[(y*MapWidth)+x].Tile;
    		// Calculate the texture coords required
                if(Tile < 16)
                    CellX = Tile;
                    CellY = 0;
                    BLeftX = CellX * (XSize);
                    BLeftY = 1.0f-(1*YSize);
                    CellY= (Tile/16)+1;
                    CellX = Tile -((CellY-1)*16);
                    BLeftX = CellX*XSize;
                    BLeftY = 1.0f-(CellY*YSize);
                glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
                // Draw the quad with the relevant texture position  
                    glTexCoord2f(BLeftX, BLeftY); 
                    glVertex2f(XOffset+ScrStartX, TileSize+YOffset+ScrStartY);
                    glTexCoord2f(BLeftX+XSize, BLeftY); 
                    glVertex2f(TileSize+XOffset+ScrStartX, TileSize+YOffset+ScrStartY);
                    glTexCoord2f(BLeftX+XSize, BLeftY+YSize); 
                    glVertex2f(TileSize+XOffset+ScrStartX, YOffset+ScrStartY);
                    glTexCoord2f(BLeftX, BLeftY+YSize); 
                    glVertex2f(XOffset+ScrStartX, YOffset+ScrStartY);

Help anyone?

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Make sure you create the list after you have a valid rendeing context created. Otherwise your list will contain nothing. If this list is getting created in a constructor of a static object, or you just call the map loader (which calls the list creator) before you have a valid openGl window, that is what will happen.

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In a similar vein I was experiencing similar glErrors regarding glGenTextures. Very frustrating. Anyway, Vamp's suggestion was right on spot with my problem: I was building textures from the constructor of my TextureMGR, which happened to be instantiate before my OpenGL window was constructed.


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