Sprites in GW-BASIC

Simple example that draws some 16x16 sprites in 4 color CGA mode to the screen.

10 SCREEN 1
20 DEFINT A-Z
30 GFXSIZE = 33 ' This value is the size of an array containing one sprite.
31 ' The GFXSIZE value calculated from the bit-depth (4 colors = 2 bit) and
32 ' the dimensions of the graphics.
33 '
34 ' In this case the tile is 16x16x2 which results in the calculation
35 ' looking like this: ((4 + INT((16 * 2 + 7) / 8) * 16) + .5) \ 2
36 ' Let's not get into what all of that means right now.
37 '
38 ' Note: In GW-BASIC you have to store each sprite in separate arrays.
39 ' In QBASIC, on the other hand, you can store several sprites in a single
40 ' array and use an index to specify the one you want to draw when calling
41 ' the PUT command.

50 DIM PLAYERGFX(GFXSIZE)
60 DIM MONSTERGFX(GFXSIZE)
70 GOSUB 800 ' Call to subroutine that reads and draws pixels
80 GET (0, 0)-(15, 15), PLAYERGFX ' Grabs graphics and puts it in an array
90 CLS ' Clear the screen
100 GOSUB 800 ' Read and draw next sprite
110 GET (0, 0)-(15, 15), MONSTERGFX
120 CLS

150 PUT (32, 56), PLAYERGFX, PSET
160 PUT (128, 80), MONSTERGFX, PSET
170 PUT (192, 32), MONSTERGFX, PSET
180 LOCATE 17: PRINT "A simple program for demonstrating
190 PRINT "16x16 tiled graphics in GW-BASIC."

300 END

800 ' Subroutine that read the DATA statement values
801 ' and then draw pixels with PSET
810 FOR y = 0 TO 15
820 FOR x = 0 TO 15
830 READ c
840 PSET (x, y), c
850 NEXT x
860 NEXT y
870 RETURN

890 ' The sprite data follows below.
901 ' Each value represent the color of an individual pixel.
892 ' Since we're in CGA 320x200 we have four colors to work with.
893 ' They are: 0 = black, 1 = cyan, 2 = magenta, 3 = white

900 ' player gfx
901 DATA 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
902 DATA 0,0,0,0,0,2,2,2,2,2,0,0,0,0,0,0
903 DATA 0,0,0,0,2,0,2,2,2,2,2,0,0,0,0,0
904 DATA 0,0,0,2,0,2,2,2,2,2,2,2,0,0,0,0
905 DATA 0,0,0,3,0,3,3,3,3,3,3,3,0,0,0,0
906 DATA 0,0,0,0,0,1,1,1,1,1,1,1,0,0,0,0
907 DATA 0,0,0,0,1,1,1,0,1,1,0,1,0,0,0,0
908 DATA 0,0,0,0,1,3,1,1,2,2,1,1,0,0,0,0
909 DATA 0,0,0,0,0,3,3,3,3,3,3,3,0,0,0,0
910 DATA 0,0,0,0,0,3,3,3,2,2,3,3,0,0,0,0
911 DATA 0,0,0,0,2,2,3,3,3,3,3,3,0,0,0,0
912 DATA 0,0,0,2,2,2,2,3,3,3,3,2,0,0,0,0
913 DATA 0,0,0,1,1,2,2,2,3,3,2,1,1,0,0,0
914 DATA 0,0,0,0,0,2,2,2,2,2,2,0,0,0,0,0
915 DATA 0,0,0,0,0,2,2,0,0,2,2,0,0,0,0,0
916 DATA 0,0,0,0,0,2,2,2,0,2,2,2,0,0,0,0

940 ' snake gfx
941 DATA 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
942 DATA 0,0,0,0,0,0,0,0,0,0,0,1,2,0,0,0
943 DATA 0,0,0,0,0,0,0,0,0,0,0,0,1,2,0,0
944 DATA 0,0,0,0,0,0,0,1,1,1,1,1,1,2,0,0
945 DATA 0,0,0,0,0,0,1,1,2,2,2,2,2,0,0,0
946 DATA 0,0,0,0,0,0,1,2,0,0,0,0,0,0,0,0
947 DATA 0,0,0,0,0,0,1,1,1,1,2,0,0,0,0,0
948 DATA 0,0,0,0,0,0,0,1,1,1,1,2,0,0,0,0
949 DATA 0,0,0,0,0,0,0,0,0,1,1,2,0,0,0,0
950 DATA 0,0,0,0,0,1,1,1,1,1,1,2,0,0,0,0
951 DATA 0,0,1,1,1,1,1,1,1,1,2,2,0,0,0,0
952 DATA 0,1,1,1,1,1,1,2,2,2,2,0,0,0,0,0
953 DATA 0,1,0,1,0,1,2,0,0,0,0,0,0,0,0,0
954 DATA 0,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0
955 DATA 0,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0
956 DATA 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0