Who already mastered the source code of that "Tetris clone in an hour with C++" thread plz do me a favour. I copied & pasted the source into my computer, and the app runs normally. But I still cannot see the Toolbar and the Preview Block. What should I do? And what does this mean: //mask first BitBlt(bmoMap,x*TILESIZE,y*TILESIZE,TILESIZE,TILESIZE,bmoBlocks,tile*TILESIZE,TILESIZE,SRCAND); //then image BitBlt(bmoMap,x*TILESIZE,y*TILESIZE,TILESIZE,TILESIZE,bmoBlocks,tile*TILESIZE,0,SRCPAINT); Mask?? Why draw twice? -NeoRc

that looks like masking the tile contours before drawing the quad (image)...