B2D and Scroll Routines
BlitzPlus Forums/BlitzPlus Programming/B2D and Scroll Routines
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| I've written a little routine that scrolls a map in all directions. Screen res is at 800 x 600, with my tiles being 64x64 pixels. I've allowed an overlap of a tile in all directions, so its blitting 12 across and 10 down To counter for the scroll, I've got an offset that moves the blit of the tiles over - till its more than 64 pixels, where I can just increase the map value and put the offset back to 0 Works well, but I cant seem to work out a method to get the tile at the screen coords. At the mo I've got this: Function get_tile(xtemp,ytemp) tilex=xtemp/64+(mapx) tiley=ytemp/64+(mapy) tilenum=maze(tilex,tiley) Return End Function But its wrong.. :( (also doesnt allow for the offset - xoff,yoff) Cant seem to work it out ! Also.. I want to have a HUD over the scrolling area, is it best to blit the map, then the HUD over it - or copy the map into a blank space on the HUD. |
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| The funtion returns nothing as it is. Try: Function get_tile(xtemp,ytemp) tilex=xtemp/64+(mapx) tiley=ytemp/64+(mapy) Return maze(tilex,tiley) End Function |
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| Sorry - should have said that 'tilex','tiley' and 'tilenum' are all global vars anyway. |
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| This simple demo should help with the math portion of a 2D pixel-perfect scrolling map (ignore the clunky tiles). http://www.blitzcoder.com/cgi-bin/showcase/showcase_showentry.pl?id=turtle177603142002002034&comments=no |
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| if mapx,mapy is the map location in pixels being drawn at top left of screen the tile the mouse is pointing to will be: (mousex+mapx)/64,(mousey+mapy)/64 |
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