git.mutantstargoat.com Git - gbajam21/blob - src/gamescr.c

   1 #include <stdlib.h>
   2 #include <string.h>
   3 #include "gbaregs.h"
   4 #include "dma.h"
   5 #include "data.h"
   6 #include "util.h"
   7 #include "intr.h"
   8 #include "input.h"
   9 #include "debug.h"
  10
  11 static void draw_tunnel(void);
  12
  13 static int nframes, backbuf;
  14 static uint16_t *vram[] = { (uint16_t*)VRAM_LFB_FB0_ADDR, (uint16_t*)VRAM_LFB_FB1_ADDR };
  15 static unsigned char *tex;
  16 static uint16_t bnstate;
  17
  18 void gamescr(void)
  19 {
  20         int i;
  21         uint16_t *cdst;
  22         unsigned char *csrc;
  23
  24         REG_DISPCNT = 4 | DISPCNT_BG2 | DISPCNT_FB1;
  25
  26         vblperf_setcolor(0xff);
  27
  28         cdst = (uint16_t*)CRAM_BG_ADDR;
  29         csrc = tuncross_cmap;
  30         for(i=0; i<256; i++) {
  31                 *cdst++ = CONV_RGB24_RGB15(csrc[0], csrc[1], csrc[2]);
  32                 csrc += 3;
  33         }
  34
  35         fillblock_16byte(vram[0], 0xffffffff, 240 * 160 / 16);
  36         fillblock_16byte(vram[1], 0xffffffff, 240 * 160 / 16);
  37
  38         tex = iwram_sbrk(32 * 32);
  39         memcpy(tex, tuncross_pixels, 32 * 32);
  40
  41         select_input(BN_DPAD);
  42
  43         nframes = 0;
  44         for(;;) {
  45                 backbuf = ++nframes & 1;
  46
  47                 bnstate = get_input();
  48
  49                 draw_tunnel();
  50
  51                 vblperf_end();
  52                 wait_vblank();
  53                 present(backbuf);
  54                 vblperf_begin();
  55         }
  56 }
  57
  58 __attribute__((noinline, target("arm"), section(".iwram")))
  59 static void draw_tunnel(void)
  60 {
  61         static int uoffs;
  62         int i, j, tx, ty, angle, depth, zoffs;
  63         uint16_t pptop, ppbot;
  64         uint16_t *top, *bot;
  65         uint32_t tun, *tunptr;
  66
  67         zoffs = nframes;
  68
  69         if(bnstate & BN_LEFT) uoffs++;
  70         if(bnstate & BN_RIGHT) uoffs--;
  71
  72         top = vram[backbuf];
  73         bot = vram[backbuf] + 159 * 240 / 2;
  74         tunptr = tunmap;
  75         for(i=0; i<80; i++) {
  76 #ifdef VBLBAR
  77                 top++;
  78                 bot++;
  79                 tunptr++;
  80
  81                 for(j=1; j<240/2; j++) {
  82 #else
  83                 for(j=0; j<240/2; j++) {
  84 #endif
  85                         tun = *tunptr++;
  86
  87                         angle = tun & 0xff;
  88                         depth = (tun >> 8) & 0xff;
  89                         tx = ((angle >> 1) + uoffs) & 0x1f;
  90                         ty = ((depth >> 1) + zoffs) & 0x1f;
  91                         pptop = tex[(ty << 5) + tx];
  92                         tx = ~((angle >> 1) - uoffs) & 0x1f;
  93                         ppbot = tex[(ty << 5) + tx];
  94
  95                         angle = (tun >> 16) & 0xff;
  96                         depth = (tun >> 24) & 0xff;
  97                         tx = ((angle >> 1) + uoffs) & 0x1f;
  98                         ty = ((depth >> 1) + zoffs) & 0x1f;
  99                         pptop |= (uint16_t)tex[(ty << 5) + tx] << 8;
 100                         tx = ~((angle >> 1) - uoffs) & 0x1f;
 101                         ppbot |= (uint16_t)tex[(ty << 5) + tx] << 8;
 102
 103                         *top++ = pptop;
 104                         *bot++ = ppbot;
 105                 }
 106                 bot -= 240;
 107         }
 108 }