From: John Tsiombikas <nuclear@member.fsf.org>
Date: Mon, 19 Apr 2021 17:15:41 +0000 (+0300)
Subject: tunnel rotation with lower-res scaled-up tunnel
X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=gbajam21;a=commitdiff_plain;h=b88c03f1cf5b5f66bec905e5b43e797abf8c18e0

tunnel rotation with lower-res scaled-up tunnel
---

diff --git a/Makefile b/Makefile
index f89cedd..26ffc65 100644
--- a/Makefile
+++ b/Makefile
@@ -73,7 +73,7 @@ data/lut.s: tools/lutgen
 	tools/lutgen >$@
 
 data/tun.map: tools/tungen
-	tools/tungen -s 240x160 >$@
+	tools/tungen -s 160x160 >$@
 
 data/snd.bin: $(audata) tools/mmutil/mmutil
 	tools/mmutil/mmutil -o$@ -hdata/snd.h $(audata)
diff --git a/src/gamescr.c b/src/gamescr.c
index ec4f353..452709c 100644
--- 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;
@@ -74,73 +78,67 @@ void gamescr(void)
 		vblperf_end();
 		wait_vblank();
 		present(backbuf);
+
+		tunrot = nframes;
+		bgmat[0] = (COS(tunrot) * 280) >> 8;
+		bgmat[1] = (-SIN(tunrot) * 280) >> 8;
+		bgmat[2] = (SIN(tunrot) * 280) >> 8;
+		bgmat[3] = (COS(tunrot) * 280) >> 8;
+		bgx = (120 << 8) - bgmat[0] * 120 + bgmat[1] * -80;
+		bgy = (80 << 8) - bgmat[2] * 120 + bgmat[3] * -80;
+
 		vblperf_begin();
 	}
 }
 
-static int32_t bgmat[4];
-static int32_t bgx, bgy;
-
 __attribute__((noinline, target("arm"), section(".iwram")))
 static void draw_tunnel(void)
 {
-	static short uoffs;
-	int i, j, tx, ty, angle, depth, zoffs;
+	int i, j, tx, ty, angle, depth, zoffs, uoffs;
 	uint16_t pptop, ppbot;
 	uint16_t *top, *bot;
 	uint32_t tun, *tunptr;
 
 	zoffs = nframes;
 
-	if(bnstate & BN_LT) uoffs++;
-	if(bnstate & BN_RT) uoffs--;
-
-	bgmat[0] = COS(uoffs) << 1;
-	bgmat[1] = -SIN(uoffs) << 1;
-	bgmat[2] = SIN(uoffs) << 1;
-	bgmat[3] = COS(uoffs) << 1;
-	bgx = (120 << 8) - bgmat[0] * 120 + bgmat[1] * -80;
-	bgy = (80 << 8) - bgmat[2] * 120 + bgmat[3] * -80;
+	uoffs = tunrot;
 
-	top = vram[backbuf];
-	bot = vram[backbuf] + 159 * 240 / 2;
+	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
-		top++;
-		bot++;
-		tunptr++;
-
-		for(j=1; j<240/2; j++) {
-#else
-		for(j=0; j<240/2; j++) {
+			if(j == 160/4) {
+				tunptr++;
+				top++;
+				bot++;
+				continue;
+			}
 #endif
 			tun = *tunptr++;
 
 			angle = tun & 0xff;
 			depth = (tun >> 8) & 0xff;
-//			tx = ((angle >> 1) - uoffs) & 0x1f;
-			tx = (angle >> 1) & 0x1f;
+			tx = ((angle >> 1) - uoffs) & 0x1f;
 			ty = ((depth >> 1) + zoffs) & 0x1f;
 			pptop = tex[(ty << 5) + tx];
-//			tx = ~((angle >> 1) + uoffs) & 0x1f;
-			tx = ~(angle >> 1) & 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) & 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) & 0x1f;
+			tx = ~((angle >> 1) + uoffs) & 0x1f;
 			ppbot |= (uint16_t)tex[(ty << 5) + tx] << 8;
 
 			*top++ = pptop;
 			*bot++ = ppbot;
 		}
-		bot -= 240;
+		top += 40;
+		bot -= 240 - 40;
 	}
 }
 
@@ -180,6 +178,7 @@ 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));
 
diff --git a/tools/tungen.c b/tools/tungen.c
index 62e0d63..ec21217 100644
--- a/tools/tungen.c
+++ b/tools/tungen.c
@@ -52,8 +52,8 @@ invalopt:	fprintf(stderr, "invalid argument: %s\n", argv[i]);
 	prev_r = 0.0f;
 	for(i=0; i<VDIV; i++) {
 		float v = (float)(VDIV - i) / (float)VDIV;
-		float r = 4.0 / v + 16;
-		float z = v * 400.0f;
+		float r = 1.5 / v + 16;
+		float z = v * 200.0f;
 
 		/* don't bother drawing rings < 1 pixel apart */
 		if(fabs(r - prev_r) < 0.05) continue;