sprites 256c, shadow oam, sprite transforms, sinlut

[gbajam21] / src / sprite.c

diff --git a/src/sprite.c b/src/sprite.c
new file mode 100644 (file)
index 0000000..e4253fb
--- /dev/null
+++ b/src/sprite.c
@@ -0,0 +1,79 @@
+#include "sprite.h"
+#include "gbaregs.h"
+
+
+void spr_setup(int xtiles, int ytiles, unsigned char *pixels, unsigned char *cmap)
+{
+       int i, j, num_tiles;
+       uint16_t *cptr, *src, *dst;
+
+       num_tiles = xtiles * ytiles;
+       dst = (uint16_t*)VRAM_LFB_OBJ_ADDR;
+       src = (uint16_t*)pixels;
+       for(i=0; i<num_tiles; i++) {
+               /* copy every row of tile i (8x8) */
+               for(j=0; j<8; j++) {
+                       *dst++ = src[j * 64];
+                       *dst++ = src[j * 64 + 1];
+                       *dst++ = src[j * 64 + 2];
+                       *dst++ = src[j * 64 + 3];
+               }
+               src += 4;
+
+               if((i & 15) == 15) {
+                       src += 7 * 64;  /* skip to the next row of tiles (skip 7 rows of pixels) */
+               }
+       }
+
+       cptr = (uint16_t*)CRAM_OBJ_ADDR;
+       for(i=0; i<256; i++) {
+               unsigned char r = *cmap++ >> 3;
+               unsigned char g = *cmap++ >> 3;
+               unsigned char b = *cmap++ >> 3;
+               *cptr++ = r | (g << 5) | (b < 10);
+       }
+}
+
+void spr_clear(void)
+{
+       int i;
+
+       for(i=0; i<128; i++) {
+               spr_oam_clear(0, i);
+       }
+}
+
+void spr_oam(uint16_t *oam, int idx, int spr, int x, int y, unsigned int flags)
+{
+       if(!oam) oam = (uint16_t*)OAM_ADDR;
+
+       oam += idx << 2;
+
+       oam[0] = (y & 0xff) | (flags & 0xff00);
+       oam[1] = (x & 0x1ff) | ((flags >> 8) & 0xfe00);
+       oam[2] = (spr & 0x3ff) | ((flags & 3) << 10);
+}
+
+void spr_spr_oam(uint16_t *oam, int idx, struct sprite *spr)
+{
+       int i;
+       struct hwsprite *s;
+
+       s = spr->hwspr;
+       for(i=0; i<spr->num_hwspr; i++) {
+               spr_oam(oam, idx, s->id, spr->x + s->x, spr->y + s->y, s->flags);
+               s++;
+       }
+}
+
+void spr_transform(uint16_t *oam, int idx, int16_t *mat)
+{
+       if(!oam) oam = (uint16_t*)OAM_ADDR;
+
+       oam += (idx << 4) + 3;
+
+       oam[0] = *mat++;
+       oam[4] = *mat++;
+       oam[8] = *mat++;
+       oam[12] = *mat;
+}