+
+__attribute__((noinline, target("arm"), section(".iwram")))
+static void draw_tunnel(void)
+{
+ 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 & 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];
+ for(i=0; i<160; i++) {
+ startx = tunx;
+ starty = tuny;
+ for(j=0; j<240/2; j++) {
+ 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 = tex[(ty << 5) + tx];
+
+ 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;
+
+ *top++ = pptop;
+ }
+
+ tunx = startx + tunmat[1];
+ tuny = starty + tunmat[3];
+ }
+}
+
+__attribute__((noinline, target("arm"), section(".iwram")))
+static void vblank(void)
+{
+ uint16_t bnstate;
+ int16_t mat[4];
+ static short gate_speed;
+
+ bnstate = ~REG_KEYINPUT;
+ if(bnstate & BN_DPAD) {
+ if(gate_speed < 5) {
+ gate_speed++;
+ }
+
+ if(bnstate & BN_LEFT) x -= gate_speed;
+ if(bnstate & BN_RIGHT) x += gate_speed;
+ if(bnstate & BN_UP) y -= gate_speed;
+ if(bnstate & BN_DOWN) y += gate_speed;
+
+ if(x < 0) x = 0;
+ if(x > 239) x = 239;
+ if(y < 0) y = 0;
+ if(y > 159) y = 159;
+ } else {
+ gate_speed = 0;
+ }
+
+ 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);
+ mat[1] = -SIN(rot);
+ mat[2] = SIN(rot);
+ mat[3] = COS(rot);
+ spr_transform(oam, 0, mat);
+
+
+ dma_copy16(3, (void*)OAM_ADDR, oam, sizeof oam / 2, 0);
+}