optimizations

[gbajam22] / src / util.h

diff --git a/src/util.h b/src/util.h
index 3bbafbd..2e5f013 100644 (file)
--- a/src/util.h
+++ b/src/util.h
@@ -18,10 +18,14 @@
                REG_DISPCNT = DISPCNT_BG2 | DISPCNT_OBJ | 4 | ((x) << 4); \
        } while(0)
 
+#define ARM_IWRAM      __attribute__((noinline, target("arm"), section(".iwram")))
+
 #else  /* non-GBA build */
 #define wait_vblank()
 
 void present(int buf);         /* defined in src/pc/main.c */
+
+#define ARM_IWRAM
 #endif
 
 #define set_bg_color(idx, r, g, b) \
@@ -29,8 +33,14 @@ void present(int buf);               /* defined in src/pc/main.c */
 
 extern int16_t sinlut[];
 
-#define SIN(x) sinlut[(x) & 0xff]
-#define COS(x) sinlut[((x) + 64) & 0xff]
+#define SINLUT_BITS            8
+#define SINLUT_SIZE            (1 << SINLUT_BITS)
+
+#define SIN(angle) \
+       ((int32_t)sinlut[((angle) >> (16 - SINLUT_BITS)) & (SINLUT_SIZE - 1)] << 1)
+
+#define COS(angle) \
+       ((int32_t)sinlut[(((angle) >> (16 - SINLUT_BITS)) + (SINLUT_SIZE / 4)) & (SINLUT_SIZE - 1)] << 1)
 
 int iwram_brk(void *addr);
 void *iwram_sbrk(intptr_t delta);