wonky sweep

[gbajam21] / src / gamescr.c

diff --git a/src/gamescr.c b/src/gamescr.c
index 39ed733..aef4966 100644 (file)
--- a/src/gamescr.c
+++ b/src/gamescr.c
@@ -24,6 +24,10 @@ static uint16_t oam[4 * MAX_SPR];
 static short x = 120, y = 80;
 static unsigned char rot;
 
+static int32_t bgmat[4];
+static int32_t bgx, bgy;
+static int32_t tunrot;
+
 void gamescr(void)
 {
        int i;
@@ -81,52 +85,59 @@ 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;
+       int i, j, tx, ty, angle, depth, zoffs, uoffs, flip;
+       int tunsweep;
        uint16_t pptop, ppbot;
        uint16_t *top, *bot;
        uint32_t tun, *tunptr;
 
+       tunsweep = (SIN(nframes) >> 2) + 64;
+       if(tunsweep > 127) tunsweep = 127;
+
+       flip = tunsweep >= 64;
+
+       tunsweep = (tunsweep & 0x3f);
+       if(tunsweep >= 32) tunsweep = 63 - tunsweep;
+
        zoffs = nframes;
 
-       if(bnstate & BN_LT) uoffs++;
-       if(bnstate & BN_RT) uoffs--;
+       uoffs = tunrot >> 1;
 
        top = vram[backbuf];
        bot = vram[backbuf] + 159 * 240 / 2;
-       tunptr = tunmap;
+       tunptr = tunmap + tunsweep * 9600;
+       if(flip) tunptr += 240/2;
        for(i=0; i<80; i++) {
-#ifdef VBLBAR
-               top++;
-               bot++;
-               tunptr++;
-
-               for(j=1; j<240/2; j++) {
-#else
                for(j=0; j<240/2; j++) {
-#endif
-                       tun = *tunptr++;
+                       if(flip) {
+                               tun = *--tunptr;
+                               tun = (tun >> 16) | (tun << 16);
+                       } else {
+                               tun = *tunptr++;
+                       }
 
                        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;
+                       tx = ~((angle >> 1) + uoffs) & 0x1f;
                        ppbot = tex[(ty << 5) + tx];
 
                        angle = (tun >> 16) & 0xff;
                        depth = (tun >> 24) & 0xff;
-                       tx = ((angle >> 1) + uoffs) & 0x1f;
+                       tx = ((angle >> 1) - uoffs) & 0x1f;
                        ty = ((depth >> 1) + zoffs) & 0x1f;
                        pptop |= (uint16_t)tex[(ty << 5) + tx] << 8;
-                       tx = ~((angle >> 1) - uoffs) & 0x1f;
+                       tx = ~((angle >> 1) + uoffs) & 0x1f;
                        ppbot |= (uint16_t)tex[(ty << 5) + tx] << 8;
 
                        *top++ = pptop;
                        *bot++ = ppbot;
                }
                bot -= 240;
+
+               if(flip) tunptr += 240;
        }
 }
 
@@ -159,13 +170,14 @@ static void vblank(void)
        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);