shade LUT in iwram

[gbajam21] / src / gamescr.c

diff --git a/src/gamescr.c b/src/gamescr.c
index 6eee713..416e99c 100644 (file)
--- a/src/gamescr.c
+++ b/src/gamescr.c
@@ -15,7 +15,7 @@ static void vblank(void);
 
 static int nframes, num_vbl, backbuf;
 static uint16_t *vram[] = { (uint16_t*)VRAM_LFB_FB0_ADDR, (uint16_t*)VRAM_LFB_FB1_ADDR };
-static unsigned char *tex;
+static unsigned char *tex, *shadelut;
 static uint16_t bnstate;
 
 #define MAX_SPR                4
@@ -36,7 +36,7 @@ void gamescr(void)
 
        REG_DISPCNT = 4 | DISPCNT_BG2 | DISPCNT_OBJ | DISPCNT_FB1;
 
-       vblperf_setcolor(0xff);
+       vblperf_setcolor(0xff);//192);
 
        /* sprite setup */
        spr_setup(16, 16, spr_game_pixels, spr_game_cmap);
@@ -60,6 +60,8 @@ void gamescr(void)
 
        tex = iwram_sbrk(32 * 32);
        memcpy(tex, tuncross_pixels, 32 * 32);
+       shadelut = iwram_sbrk(256 * 8);
+       memcpy(shadelut, tuncross_shade, 256 * 8);
 
        scale = 0x100;//230;
        REG_BG2PA = scale;
@@ -91,12 +93,14 @@ void gamescr(void)
 }
 
 #define TUN_U(x)       ((x) & 0x3f)
-#define TUN_V(x)       (((x) >> 7) & 0x1ff)
+#define TUN_V(x)       (((x) >> 6) & 0x3ff)
+#define TEXEL(x, y, lvl) \
+       shadelut[((int)tex[((y) << 5) + (x)] << 3) + (lvl)]
 
 __attribute__((noinline, target("arm"), section(".iwram")))
 static void draw_tunnel(void)
 {
-       int i, j, tx, ty, u, v, angle, depth, zoffs, uoffs, flip, tunturn;
+       int i, j, tx, ty, u, v, angle, depth, zoffs, uoffs, flip, tunturn, shade;
        static int tunsweep;
        uint16_t pptop, ppbot;
        uint16_t *top, *bot;
@@ -111,7 +115,7 @@ static void draw_tunnel(void)
        tunturn = abs(tunsweep) & 0x1f;
 
        zoffs = num_vbl;
-       uoffs = 0;//(flip ? -num_vbl : num_vbl) >> 2;
+       uoffs = (flip ? -num_vbl : num_vbl) >> 1;
 
        top = vram[backbuf];
        bot = vram[backbuf] + 159 * 240 / 2;
@@ -125,19 +129,21 @@ static void draw_tunnel(void)
 
                                angle = TUN_U(tun >> 16);
                                depth = TUN_V(tun >> 16);
+                               shade = depth >> 7;
                                tx = ~(angle - uoffs) & 0x1f;
-                               ty = (depth + zoffs) & 0x1f;
-                               pptop = tex[(ty << 5) + tx];
+                               ty = ((depth >> 1) + zoffs) & 0x1f;
+                               pptop = TEXEL(tx, ty, shade);
                                tx = (angle + uoffs) & 0x1f;
-                               ppbot = tex[(ty << 5) + tx];
+                               ppbot = TEXEL(tx, ty, shade);
 
                                angle = TUN_U(tun);
                                depth = TUN_V(tun);
+                               shade = depth >> 7;
                                tx = ~(angle - uoffs) & 0x1f;
-                               ty = (depth + zoffs) & 0x1f;
-                               pptop |= (uint16_t)tex[(ty << 5) + tx] << 8;
+                               ty = ((depth >> 1) + zoffs) & 0x1f;
+                               pptop |= (uint16_t)TEXEL(tx, ty, shade) << 8;
                                tx = (angle + uoffs) & 0x1f;
-                               ppbot |= (uint16_t)tex[(ty << 5) + tx] << 8;
+                               ppbot |= (uint16_t)TEXEL(tx, ty, shade) << 8;
 
                                *top++ = pptop;
                                *bot++ = ppbot;
@@ -152,19 +158,21 @@ static void draw_tunnel(void)
 
                                angle = TUN_U(tun);
                                depth = TUN_V(tun);
+                               shade = depth >> 7;
                                tx = (angle - uoffs) & 0x1f;
-                               ty = (depth + zoffs) & 0x1f;
-                               pptop = tex[(ty << 5) + tx];
+                               ty = ((depth >> 1) + zoffs) & 0x1f;
+                               pptop = TEXEL(tx, ty, shade);
                                tx = ~(angle + uoffs) & 0x1f;
-                               ppbot = tex[(ty << 5) + tx];
+                               ppbot = TEXEL(tx, ty, shade);
 
                                angle = TUN_U(tun >> 16);
                                depth = TUN_V(tun >> 16);
+                               shade = depth >> 7;
                                tx = (angle - uoffs) & 0x1f;
-                               ty = (depth + zoffs) & 0x1f;
-                               pptop |= (uint16_t)tex[(ty << 5) + tx] << 8;
+                               ty = ((depth >> 1) + zoffs) & 0x1f;
+                               pptop |= (uint16_t)TEXEL(tx, ty, shade) << 8;
                                tx = ~(angle + uoffs) & 0x1f;
-                               ppbot |= (uint16_t)tex[(ty << 5) + tx] << 8;
+                               ppbot |= (uint16_t)TEXEL(tx, ty, shade) << 8;
 
                                *top++ = pptop;
                                *bot++ = ppbot;