+
+ tunrot = nframes;
+ bgmat[0] = (COS(tunrot) * 140) >> 8;
+ bgmat[1] = (-SIN(tunrot) * 140) >> 8;
+ bgmat[2] = (SIN(tunrot) * 140) >> 8;
+ bgmat[3] = (COS(tunrot) * 140) >> 8;
+ bgx = (120 << 8) - bgmat[0] * 120 + bgmat[1] * -80;
+ bgy = (80 << 8) - bgmat[2] * 120 + bgmat[3] * -80;
+
+ vblperf_begin();
+ }
+}
+
+__attribute__((noinline, target("arm"), section(".iwram")))
+static void draw_tunnel(void)
+{
+ int i, j, tx, ty, angle, depth, zoffs, uoffs;
+ uint16_t pptop, ppbot;
+ uint16_t *top, *bot;
+ uint32_t tun, *tunptr;
+
+ zoffs = nframes;
+
+ uoffs = tunrot >> 1;
+
+ top = vram[backbuf] + 20;
+ bot = vram[backbuf] + 159 * 240 / 2 + 20;
+ tunptr = tunmap;
+ for(i=0; i<80; i++) {
+ for(j=0; j<160/2; j++) {
+#ifdef VBLBAR
+ if(j == 160/4) {
+ tunptr++;
+ top++;
+ bot++;
+ continue;
+ }
+#endif
+ tun = *tunptr++;
+
+ angle = tun & 0xff;
+ depth = (tun >> 8) & 0xff;
+ 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;
+ 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;
+ }
+ top += 40;
+ bot -= 240 - 40;
+ }
+}
+
+__attribute__((noinline, target("arm"), section(".iwram")))
+static void vblank(void)
+{
+ uint16_t bnstate;
+ int16_t mat[4];
+ static short gate_speed;
+
+ REG_BG2PA = bgmat[0];
+ REG_BG2PB = bgmat[1];
+ REG_BG2PC = bgmat[2];
+ REG_BG2PD = bgmat[3];
+ REG_BG2X = bgx;
+ REG_BG2Y = bgy;
+
+ 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;