the sin lut was too small for any kind of reasonable resolution in high

framerates

diff --git a/src/rbench.c b/src/rbench.c
index 7202c1a..8b9e23f 100644 (file)
--- a/src/rbench.c
+++ b/src/rbench.c
@@ -33,7 +33,7 @@ void cleanup(void)
 
 #define XORRGB(x, y, zoom, r, g, b) \
        do { \
-               int xor = (((x) - fb_width/2) * (zoom) >> 10) ^ (((y) - fb_height/2) * (zoom) >> 10); \
+               int xor = (((x) - fb_width/2) * (zoom) >> 16) ^ (((y) - fb_height/2) * (zoom) >> 16); \
                (r) = xor >> 2; \
                (g) = xor >> 1; \
                (b) = xor; \
@@ -46,9 +46,9 @@ void redraw(void)
        uint16_t *fbptr16;
        uint32_t *fbptr32;
 
-       xoffs = COS(time_msec >> 5) * fb_width >> 7;
-       yoffs = SIN(time_msec >> 4) * fb_height >> 8;
-       zoom = ((SIN(time_msec >> 4) + 256) << 1) + 512;
+       xoffs = COS(time_msec >> 3) * fb_width >> 15;
+       yoffs = SIN(time_msec >> 2) * fb_height >> 16;
+       zoom = (SIN(time_msec >> 5) >> 1) + 65536;
 
        switch(fb_bpp) {
        case 15:

diff --git a/src/util.h b/src/util.h
index 9f0eb4d..6880649 100644 (file)
--- a/src/util.h
+++ b/src/util.h
@@ -14,8 +14,8 @@ typedef unsigned int uint32_t;
 
 extern int sinlut[];
 
-#define SIN(x) sinlut[(x) & 0xff]
-#define COS(x) sinlut[((x) + 64) & 0xff]
+#define SIN(x) sinlut[(x) & 0x3ff]
+#define COS(x) sinlut[((x) + 512) & 0x3ff]
 
 int mask_to_shift(unsigned int mask);
 

diff --git a/tools/lutgen.c b/tools/lutgen.c
index a573de1..a2cc1ed 100644 (file)
--- a/tools/lutgen.c
+++ b/tools/lutgen.c
@@ -10,9 +10,9 @@ int main(void)
        puts("\t.globl sinlut");
        puts("_sinlut:");
        puts("sinlut:");
-       for(i=0; i<256; i++) {
-               float x = sin((float)i / 128.0f * M_PI);
-               printf("\t.long %d\n", (int)(x * 256.0f));
+       for(i=0; i<1024; i++) {
+               float x = sin((float)i / 512.0f * M_PI);
+               printf("\t.long %d\n", (int)(x * 65536.0f));
        }
        return 0;
 }