mirror of
https://github.com/sehugg/8bitworkshop.git
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461 lines
10 KiB
C
461 lines
10 KiB
C
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//#resource "astrocade.inc"
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#include "aclib.h"
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//#link "aclib.s"
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#include "acbios.h"
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//#link "acbios.s"
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#include "acfast.h"
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//#link "acfast.s"
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//#link "hdr_autostart.s"
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#include <stdlib.h>
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#include <string.h>
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#pragma opt_code_speed
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// reserve 240 bytes to expand screen RAM to 4eff
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byte UNUSED[0xf0];
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#define SKYH 35
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#define GNDH 45
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#define BOTTOM (35+45)
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#define DASH_Y (BOTTOM+8)
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#define PLAYER_Y (BOTTOM-67)
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#define DASH_HEIGHT 16
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/*{pal:"astrocade",layout:"astrocade"}*/
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const byte palette[8] = {
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0x07, 0xA5, 0x00, 0x03,
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0xE6, 0xE5, 0xE4, 0xE3,
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};
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/*{pal:"astrocade",layout:"astrocade"}*/
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const byte dash_palette[4] = {
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0x05, 0x53, 0x86, 0x00,
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};
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/*{pal:"astrocade"}*/
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const byte ground_colors[8] = {
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0xA5, 0xA4, 0xA3, 0xA2, 0x91, 0x81, 0x80, 0x01,
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};
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/*{pal:"astrocade"}*/
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const byte sky_colors[4*8] = {
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0xE6, 0xE5, 0xE4, 0xE3,
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0xE5, 0xE4, 0xF3, 0x12,
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0xE4, 0xE3, 0x12, 0x22,
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0xE3, 0x12, 0x22, 0x44,
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0x12, 0x22, 0x44, 0x64,
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0x12, 0x22, 0x20, 0xE0,
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0x12, 0x22, 0xE0, 0x00,
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0x11, 0xE0, 0x00, 0x00,
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};
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const byte CURBS[4*16] = {
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/*{w:16,h:16,bpp:2,brev:1}*/
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0xBF, 0xFF, 0xFF, 0xFA,
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0xBF, 0xFF, 0xFF, 0xFA,
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0xAF, 0xFF, 0xFF, 0xEA,
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0xAF, 0xFF, 0xFF, 0xEA,
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0xAB, 0xFF, 0xFF, 0xAA,
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0xAB, 0xFF, 0xFF, 0xAA,
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0xAA, 0xFF, 0xFE, 0xAA,
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0xAA, 0xFF, 0xFE, 0xAA,
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0xAA, 0xBF, 0xFA, 0xAA,
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0xAA, 0xBF, 0xFA, 0xAA,
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0xAA, 0xAF, 0xEA, 0xAA,
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0xAA, 0xAB, 0xAA, 0xAA,
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0xAA, 0xAA, 0xAA, 0xAA,
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0xAA, 0xAA, 0xAA, 0xAA,
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0xAA, 0xAA, 0xAA, 0xAA,
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0xAA, 0xAA, 0xAA, 0xAA,
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};
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const byte CAR_10_MASK[2+4*10] = {
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4,10,
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/*{w:16,h:10,bpp:2,brev:1}*/
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0x03, 0xC0, 0x03, 0xC0,
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0x03, 0xFF, 0xFF, 0xC0,
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0x00, 0x3F, 0xFC, 0x00,
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0x00, 0xFF, 0xFF, 0x00,
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0x3F, 0xFF, 0xFF, 0xFC,
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0xFF, 0xFF, 0xFF, 0xFF,
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0xFF, 0xFF, 0xFF, 0xFF,
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0xFF, 0xFF, 0xFF, 0xFF,
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0xFF, 0xFF, 0xFF, 0xFF,
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0x3F, 0xC0, 0x03, 0xFC,
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};
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const byte CAR_10_INV[2+4*10] = {
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4,10,
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/*{w:16,h:10,bpp:2,brev:1}*/
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0x02, 0x80, 0x02, 0x80,
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0x02, 0x95, 0x56, 0x80,
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0x00, 0x16, 0x94, 0x00,
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0x00, 0x58, 0x25, 0x00,
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0x2A, 0x51, 0x45, 0xA8,
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0x82, 0x6A, 0xA9, 0x82,
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0xAA, 0x96, 0x96, 0xAA,
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0xAA, 0x56, 0x95, 0xAA,
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0xAA, 0x7F, 0xFD, 0xAA,
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0x2A, 0xC0, 0x03, 0xA8,
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};
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const byte CAR_10[2+4*10] = {
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4,10,
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/*{w:16,h:10,bpp:2,brev:1}*/
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0x01, 0x40, 0x01, 0x40,
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0x01, 0x6A, 0xA9, 0x40,
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0x00, 0x29, 0x68, 0x00,
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0x02, 0xA7, 0xDA, 0x80,
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0x15, 0xAC, 0x3A, 0x54,
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0x7D, 0x95, 0x56, 0x7D,
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0x55, 0x69, 0x69, 0x55,
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0x55, 0xA9, 0x6A, 0x55,
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0x55, 0x80, 0x02, 0x55,
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0x15, 0x00, 0x00, 0x54,
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};
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const byte CAR_9[2+4*9] = {
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4,9,
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/*{w:16,h:9,bpp:2,brev:1}*/
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0x00, 0x50, 0x05, 0x00,
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0x00, 0x5A, 0xA5, 0x00,
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0x00, 0x29, 0x68, 0x00,
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0x02, 0xA7, 0xDA, 0x80,
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0x15, 0xAC, 0x3A, 0x54,
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0x1D, 0x95, 0x56, 0x7C,
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0x15, 0x69, 0x69, 0x54,
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0x15, 0xA9, 0x6A, 0x54,
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0x15, 0x80, 0x02, 0x54,
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};
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const byte CAR_8[2+4*8] = {
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4,8,
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/*{w:16,h:8,bpp:2,brev:1}*/
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0x00, 0x14, 0x14, 0x00,
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0x00, 0x1A, 0xA4, 0x00,
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0x00, 0x29, 0x68, 0x00,
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0x02, 0xA7, 0xDA, 0x80,
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0x05, 0xA0, 0x0A, 0x50,
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0x0D, 0x55, 0x55, 0x70,
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0x05, 0xA9, 0x6A, 0x50,
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0x05, 0x00, 0x00, 0x50,
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};
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const byte CAR_7[2+4*7] = {
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4,7,
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/*{w:16,h:7,bpp:2,brev:1}*/
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0x00, 0x04, 0x10, 0x00,
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0x00, 0x06, 0x90, 0x00,
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0x00, 0x29, 0x68, 0x00,
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0x00, 0xA7, 0xDA, 0x00,
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0x03, 0x55, 0x55, 0xC0,
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0x01, 0x6A, 0xA9, 0x40,
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0x01, 0x40, 0x01, 0x40,
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};
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const byte CAR_6[2+4*6] = {
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2,6,
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/*{w:8,h:6,bpp:2,brev:1}*/
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0x04, 0x10,
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0x06, 0x90,
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0x0B, 0xE0,
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0x55, 0x55,
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0x5A, 0xA5,
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0x50, 0x05,
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};
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const byte CAR_5[2+4*5] = {
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2,5,
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/*{w:8,h:5,bpp:2,brev:1}*/
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0x04, 0x10,
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0x0A, 0xA0,
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0x05, 0x50,
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0x16, 0x94,
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0x14, 0x14,
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};
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const byte CAR_4[2+4*4] = {
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2,4,
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/*{w:8,h:4,bpp:2,brev:1}*/
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0x01, 0x40,
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0x0A, 0xA0,
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0x05, 0x50,
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0x04, 0x10,
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};
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const byte CAR_3[2+4*3] = {
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2,3,
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/*{w:8,h:3,bpp:2,brev:1}*/
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0x01, 0x40,
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0x06, 0x90,
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0x04, 0x10,
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};
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const byte CAR_2[2+4*2] = {
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2,2,
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/*{w:8,h:2,bpp:2,brev:1}*/
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0x02, 0x80,
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0x01, 0x40,
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};
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const byte* const CAR_PATTERNS[16] = {
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CAR_10, CAR_10, CAR_10,
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CAR_9, CAR_9, CAR_8,
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CAR_7, CAR_6, CAR_5, CAR_4, CAR_3,
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CAR_2, CAR_2, CAR_2, CAR_2
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};
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// Z-table -- y = 800/(x*0.5+16)
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const byte ZTAB[128] = {
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50,48,47,45,44,43,42,41,40,39,38,37,36,35,34,34,33,32,32,31,30,30,29,29,28,28,27,27,26,26,25,25,25,24,24,23,23,23,22,22,22,21,21,21,21,20,20,20,20,19,19,19,19,18,18,18,18,17,17,17,17,17,17,16,16,16,16,16,16,15,15,15,15,15,15,14,14,14,14,14,14,14,14,13,13,13,13,13,13,13,13,13,12,12,12,12,12,12,12,12,12,12,11,11,11,11,11,11,11,11,11,11,11,11,10,10,10,10,10,10,10,10,10,10,10,10,10,10,
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};
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byte get1z(byte x) __z88dk_fastcall {
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return (x<128) ? ZTAB[x] : (255-x)/16+2;
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}
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#define PAT_ROAD 0x00
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#define PAT_SKY 0x55
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#define PAT_GROUND 0xaa
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byte __at(0xfff) WASTER; // to soak up shifter residue
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byte road_width = 142;
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byte road_cenx = 80;
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int road_inc = 0;
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sbyte road_curve = 0;
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byte curve_dir = 1;
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word track_pos = 0;
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byte speed = 4;
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byte fill_grass = 0;
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// interrupt handler declarations
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void inthandler1() __interrupt;
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void inthandler2() __interrupt;
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void inthandler3() __interrupt;
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void inthandler4() __interrupt;
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void inthandler5() __interrupt;
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// pointers to the interrupt handlers
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const t_interrupt_handler const intvector1 = &inthandler1;
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const t_interrupt_handler const intvector2 = &inthandler2;
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const t_interrupt_handler const intvector3 = &inthandler3;
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const t_interrupt_handler const intvector4 = &inthandler4;
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const t_interrupt_handler const intvector5 = &inthandler5;
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// bottom of screen, set sky palette
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// update track_pos every 1/60 sec
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void inthandler1() __interrupt {
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SET_RIGHT_PALETTE(_palette+4);
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hw_inlin = SKYH*2 - 2;
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track_pos += speed;
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CHANGE_INTERRUPT_VECTOR(_intvector2);
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}
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// horizon, set ground palette
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// next split calculated linearly
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void inthandler2() __interrupt {
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hw_horcb = 40;
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hw_inlin = SKYH*2 + 2 + ((track_pos&0xff)>>4);
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CHANGE_INTERRUPT_VECTOR(_intvector3);
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}
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// far split, change road color
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// next split calculated with Z lookup table
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void inthandler3() __interrupt {
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byte y = (SKYH + ZTAB[((~track_pos&0xff)>>1)]) * 2;
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hw_inlin = y > BOTTOM*2 ? BOTTOM*2 : y;
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hw_col0l = 2 ^ ((track_pos>>8)&1);
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CHANGE_INTERRUPT_VECTOR(_intvector4);
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}
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// near split, change road color until dash
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void inthandler4() __interrupt {
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hw_inlin = (BOTTOM+2)*2;
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hw_col0l = 3 ^ ((track_pos>>8)&1);
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CHANGE_INTERRUPT_VECTOR(_intvector5);
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}
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// set dash palette until bottom of screen
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void inthandler5() __interrupt {
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SET_RIGHT_PALETTE(_dash_palette);
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hw_horcb = 0;
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hw_inlin = 106*2;
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CHANGE_INTERRUPT_VECTOR(_intvector1);
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}
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// get track position, preventing race condition
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// if it changes during interrupt
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word get_track_pos(void) {
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__asm__("di");
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__asm__("ld hl,(_track_pos)");
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__asm__("ei");
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}
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// car record
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typedef struct {
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sbyte x;
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byte y;
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const byte* pattern;
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} Car;
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#define MAX_CARS 2
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Car cars[MAX_CARS];
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void draw_car(byte x1, const Car* car) {
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byte x = x1 + car->x;
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byte* dest = &vmagic[BOTTOM - car->y][x>>2];
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hw_magic = M_SHIFT(x) | M_OR;
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// is this pattern 16 pixels wide?
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if (car->pattern[0] == 4) {
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// special mask mode for cars near the edge
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if (car->pattern == CAR_10 && (x < 40 || x > 120)) {
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hw_magic = M_SHIFT(x) | M_OR;
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fast_sprite_16(CAR_10_MASK, dest);
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hw_magic = M_SHIFT(x) | M_XOR;
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fast_sprite_16(CAR_10_INV, dest);
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fill_grass = 2; // draw over grass next frame
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} else {
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// 16-pixel fast OR with background
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fast_sprite_16(car->pattern, dest);
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}
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} else {
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// 8-pixel fast OR with background
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fast_sprite_8(car->pattern, dest);
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}
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}
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void draw_cars(byte x1, byte y) {
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if (y == cars[0].y) {
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draw_car(x1, &cars[0]);
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}
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if (y == cars[1].y) {
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draw_car(x1, &cars[1]);
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}
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}
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void draw_grass(byte* start, byte* end) {
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hw_magic = 0;
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while (start < end) {
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*start++ = PAT_GROUND;
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}
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}
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void draw_road() {
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byte y,x1,x2,w,j;
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register byte* dest;
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static byte* line;
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static word xx;
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static int inc;
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static const byte* curb;
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curb = CURBS;
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line = &vmagic[BOTTOM][0];
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inc = road_inc;
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w = road_width;
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// 16-bit X coordinate
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xx = road_cenx << 8;
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// loop from bottom to top
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for (y=0; y<GNDH; y++) {
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x1 = (xx >> 8) - w/2;
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x2 = x1 + w;
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// fill in grass?
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if (fill_grass && y <= PLAYER_Y) {
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// TODO: calc redundant expr but keeps our register var
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draw_grass(line, line + x1/4);
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}
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// left side of road
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dest = line + x1/4;
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hw_magic = M_SHIFT(x1);
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WASTER = PAT_GROUND; // fill shifter with ground color
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*dest++ = curb[0];
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*dest++ = curb[1];
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// repave road, unroll loop a bit
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// (causes a little flicker on the right)
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for (j=0; j<w/8; j++) {
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*dest++ = PAT_ROAD;
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*dest++ = PAT_ROAD;
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}
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// right side of road
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dest = line + x2/4;
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hw_magic = M_SHIFT(x2);
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*dest++ = curb[2];
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*dest++ = curb[3];
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*dest = PAT_GROUND;
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// fill in grass?
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if (fill_grass && y <= PLAYER_Y) {
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draw_grass(dest, line+40);
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}
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// draw any cars which start on this line
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draw_cars(xx>>8, y);
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// next line up, update variables
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line -= 40;
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if ((y&3) == 0) curb += 4;
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xx += inc;
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inc += road_curve;
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w -= 3;
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}
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if (fill_grass) fill_grass--;
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}
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void draw_sky() {
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SYS_FILL(0x4000+0*40, 44*40, 0x00);
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SYS_FILL(0x4000+25*40, 10*40, 0x55);
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SYS_FILL(0x4000+30*40, 5*40, 0xaa);
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SYS_FILL(0x4000+33*40, 2*40, 0xff);
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}
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void draw_ground() {
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SYS_FILL(0x4000+35*40, 44*40, 0xaa);
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}
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void draw_dash() {
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SYS_FILL(0x4000+80*40, 16*40, 0x00);
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SYS_FILL(0x4000+80*40, 5*40, 0xff);
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}
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void position_cars() {
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byte x,y,zr;
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// player car
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cars[0].x = hw_p1pot/2 - 64;
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// other cars
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zr = get1z((get_track_pos() & 0xff) ^ 0xff);
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y = GNDH - zr;
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x = zr;
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cars[1].x = x;
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cars[1].y = y;
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cars[1].pattern = CAR_PATTERNS[y/4];
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if (y < 10) cars[1].y = -1; // TODO: clipping
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}
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void main(void) {
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// setup palette
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set_palette(palette);`
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// set screen height
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// set horizontal color split (position / 4)
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// set interrupt status
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set_interrupt_vector(&intvector1);
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SYS_SETOUT(96*2, 0, 0x8);
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// draw initial background
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draw_sky();
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draw_ground();
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draw_dash();
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// place player car
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cars[0].y = PLAYER_Y;
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cars[0].x = 50;
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cars[0].pattern = CAR_10;
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// player other car
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cars[1].y = BOTTOM-60;
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cars[1].x = 20;
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cars[1].pattern = CAR_6;
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// draw score
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display_string(0, DASH_Y, XPAND_COLORS(1,0), " 00:00");
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// infinite loop
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while (1) {
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position_cars();
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draw_road();
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road_curve += curve_dir;
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if (road_curve >= 21) curve_dir = -1;
|
|
if (road_curve <= -20) curve_dir = 1;
|
|
if (hw_p1ctrl & JOY_UP && speed<16) speed++;
|
|
if (hw_p1ctrl & JOY_DOWN && speed>1) speed--;
|
|
}
|
|
}
|