software tunnel rotation / lower framerate

[gbajam21] / src / gamescr.c

diff --git a/src/gamescr.c b/src/gamescr.c
index 51df533..9e9d6e1 100644 (file)
--- a/src/gamescr.c
+++ b/src/gamescr.c
@@ -24,9 +24,13 @@ static uint16_t oam[4 * MAX_SPR];
 static short x = 120, y = 80;
 static unsigned char rot;
 
+static int32_t tunrot;
+static int32_t tunmat[4], tunx, tuny;
+
 void gamescr(void)
 {
        int i;
+       int32_t scale;
        uint16_t *cdst;
        unsigned char *csrc;
 
@@ -57,6 +61,14 @@ void gamescr(void)
        tex = iwram_sbrk(32 * 32);
        memcpy(tex, tuncross_pixels, 32 * 32);
 
+       scale = 0x100;//230;
+       REG_BG2PA = scale;
+       REG_BG2PB = 0;
+       REG_BG2PC = 0;
+       REG_BG2PD = scale;
+       REG_BG2X = (120 << 8) - scale * 120;
+       REG_BG2Y = (80 << 8) - scale * 80;
+
        /*select_input(BN_DPAD);*/
 
        mask(INTR_VBLANK);
@@ -81,52 +93,66 @@ void gamescr(void)
 __attribute__((noinline, target("arm"), section(".iwram")))
 static void draw_tunnel(void)
 {
-       static int uoffs;
-       int i, j, tx, ty, angle, depth, zoffs;
-       uint16_t pptop, ppbot;
-       uint16_t *top, *bot;
-       uint32_t tun, *tunptr;
+       int i, j, tx, ty, angle, depth, zoffs, uoffs;
+       uint16_t pptop;
+       uint16_t *top;
+       uint16_t tun;
+       int32_t startx, starty;
+       uint16_t *tmap = (uint16_t*)tunmap;
 
        zoffs = nframes;
 
-       if(bnstate & BN_LT) uoffs++;
-       if(bnstate & BN_RT) uoffs--;
+       /*
+       if(bnstate & KEY_LT) tunrot++;
+       if(bnstate & KEY_RT) tunrot--;
+       */
+       tunrot = nframes;
+
+       tunmat[0] = COS(tunrot);
+       tunmat[1] = -SIN(tunrot);
+       tunmat[2] = SIN(tunrot);
+       tunmat[3] = COS(tunrot);
+       tunx = (128 << 8) - tunmat[0] * 120 + tunmat[1] * -80;
+       tuny = (128 << 8) - tunmat[2] * 120 + tunmat[3] * -80;
+
+       uoffs = tunrot;
 
        top = vram[backbuf];
-       bot = vram[backbuf] + 159 * 240 / 2;
-       tunptr = tunmap;
-       for(i=0; i<80; i++) {
-#ifdef VBLBAR
-               top++;
-               bot++;
-               tunptr++;
-
-               for(j=1; j<240/2; j++) {
-#else
+       for(i=0; i<160; i++) {
+               startx = tunx;
+               starty = tuny;
                for(j=0; j<240/2; j++) {
-#endif
-                       tun = *tunptr++;
+                       tx = (tunx >> 8) & 0xff;
+                       ty = (tuny >> 8) & 0xff;
+                       tun = tmap[(ty << 8) + tx];
+
+                       tunx += tunmat[0];
+                       tuny += tunmat[2];
 
                        angle = tun & 0xff;
                        depth = (tun >> 8) & 0xff;
-                       tx = ((angle >> 1) + uoffs) & 0x1f;
+                       tx = ((angle >> 1) - uoffs) & 0x1f;
                        ty = ((depth >> 1) + zoffs) & 0x1f;
                        pptop = tex[(ty << 5) + tx];
-                       tx = ~((angle >> 1) - uoffs) & 0x1f;
-                       ppbot = tex[(ty << 5) + tx];
 
-                       angle = (tun >> 16) & 0xff;
-                       depth = (tun >> 24) & 0xff;
-                       tx = ((angle >> 1) + uoffs) & 0x1f;
+                       tx = (tunx >> 8) & 0xff;
+                       ty = (tuny >> 8) & 0xff;
+                       tun = tmap[(ty << 8) + tx];
+
+                       tunx += tunmat[0];
+                       tuny += tunmat[2];
+
+                       angle = tun & 0xff;
+                       depth = (tun >> 8) & 0xff;
+                       tx = ((angle >> 1) - uoffs) & 0x1f;
                        ty = ((depth >> 1) + zoffs) & 0x1f;
                        pptop |= (uint16_t)tex[(ty << 5) + tx] << 8;
-                       tx = ~((angle >> 1) - uoffs) & 0x1f;
-                       ppbot |= (uint16_t)tex[(ty << 5) + tx] << 8;
 
                        *top++ = pptop;
-                       *bot++ = ppbot;
                }
-               bot -= 240;
+
+               tunx = startx + tunmat[1];
+               tuny = starty + tunmat[3];
        }
 }
 
@@ -156,16 +182,17 @@ static void vblank(void)
                gate_speed = 0;
        }
 
-       if(bnstate & BN_A) rot--;
-       if(bnstate & BN_B) rot++;
+       if(bnstate & BN_A) rot -= 2;
+       if(bnstate & BN_B) rot += 2;
+
 
        spr_oam(oam, 0, 512 + 256, x - 64, y - 64, SPR_256COL | SPR_SZ64 | SPR_DBLSZ |
                        SPR_ROTSCL | SPR_ROTSCL_SEL(0));
 
-       mat[0] = COS(rot) << 1;
-       mat[1] = -SIN(rot) << 1;
-       mat[2] = SIN(rot) << 1;
-       mat[3] = COS(rot) << 1;
+       mat[0] = COS(rot);
+       mat[1] = -SIN(rot);
+       mat[2] = SIN(rot);
+       mat[3] = COS(rot);
        spr_transform(oam, 0, mat);