In order to get some discussion going again, here's a potentially useful little routine for generating graduated colours under GD2. This is written for QPC2-style MODE 32 (I don't have a Q40 or Q60 to try an equivalent mode 33 or an SMSQ/E to handle 256 colour modes) and generates a gradually changing colour hue from black to the 8 colours of mode 8. The effect is quite nice - the routine generates seven blocks of colour in a 128x64 pixel block:
Black to blue Black to red Black to magenta Black to green Black to cyan Black to yellow Black to white This is but the result of half an hour's tinkering, no doubt someone will take this routine and substantially improve on it. Remember, if using QPC2 for example you have to start in high colour mode. Start the routine with GRAD to see it in action. The routine is reasonably well commented to help explain how it works if you wish to try to write your own routines. (If anyone's unable to save this listing from the email, I can send it provately as an attachment as I didn't want to send attachments to this list) 1000 DEFine PROCedure Grad 1010 REMark #1 allows 8 blocks of 128x64 pixels 1020 WINDOW 256,256,256,0 : CLS : CLS #0 1030 REMark r1,g1,b1 are start colours 1040 REMark r2,g2,b2 are end colours 1050 REMark Mode 32: red=0-31,green=0-63,blue=0-31 1060 r1 = 0 : g1 = 0 : b1 = 0 1070 r2 = 31 : g2 = 63 : b2 = 31 1080 REMark size of colour gradient step per line of pixels down 1090 REMark (end_colour-start_colour+1)/steps 1100 rstep = (r2-r1+1)/64 1110 gstep = (g2-g1+1)/64 1120 bstep = (b2-b1+1)/64 1130 REMark do 64 pixel high clocks of graduated colour 1140 FOR y = 0 TO 63 1150 red = INT((r1+(y*rstep))+.5) : REMark red component 1160 IF red > r2 THEN red = r2 : REMark rounding errors? 1170 green = INT((g1+(y*gstep))+.5) : REMark green component 1180 IF green > g2 THEN green = g2 : REMark rounding errors? 1190 blue = INT((b1+(y*bstep))+.5) : REMark blue component 1200 IF blue > b2 THEN blue = b2 : REMark rounding errors? 1210 nat_col=(2048*red)+(32*green)+blue: REMark combined native colour 1220 BLOCK 128,1,0,y,2048*red : REMark black to red 1230 BLOCK 128,1,128,y,2048*red+blue : REMark black to magenta 1240 BLOCK 128,1,0,y+64,32*green : REMark black to green 1250 BLOCK 128,1,128,y+64,32*green+blue : REMark black to cyan 1260 BLOCK 128,1,0,y+128,blue : REMark black to blue 1270 BLOCK 128,1,128,y+128,2048*red+32*green: REMark black to yellow 1280 BLOCK 128,1,0,y+192,nat_col : REMark black-grey-white 1290 END FOR y 1300 END DEFine Grad -- Dilwyn Jones
