1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/main.c	Sun Jan 28 20:05:26 2018 +0200
     1.3 @@ -0,0 +1,121 @@
     1.4 +#include <stdint.h>
     1.5 +#include <math.h>
     1.6 +#include "dsregs.h"
     1.7 +#include "ds3.h"
     1.8 +
     1.9 +static void xorpat(void *addr, int xsz, int ysz);
    1.10 +
    1.11 +static void *vram = VRAM_LCDC_PTR;
    1.12 +static uint16_t *bgmem = VRAM_BGB_PTR;
    1.13 +
    1.14 +#define SIN_TAB_SZ	256
    1.15 +static int32_t sintab[SIN_TAB_SZ];
    1.16 +static int32_t costab[SIN_TAB_SZ];
    1.17 +
    1.18 +int main(void)
    1.19 +{
    1.20 +	int i;
    1.21 +	uint32_t frame;
    1.22 +	int32_t m[16] = {
    1.23 +		0x10000, 0, 0, 0,
    1.24 +		0, 0x10000, 0, 0,
    1.25 +		0, 0, 0x10000, 0,
    1.26 +		0, 0, 0, 0x10000
    1.27 +	};
    1.28 +
    1.29 +	REG_POWCNT1 = POWCNT1_LCD | POWCNT1_3DREND | POWCNT1_3DGEOM | POWCNT1_2DA | POWCNT1_2DB | POWCNT1_DSWAP;
    1.30 +
    1.31 +	REG_DISPCNT = DISPCNT_MODE(1) | DISPCNT_BG0 | DISPCNT_BG0_3D;
    1.32 +	REG_B_DISPCNT = DISPCNT_MODE(1) | DISPCNT_BG2 | 5;
    1.33 +
    1.34 +	REG_B_BG2CNT = BGXCNT_BM_256X256 | BGXCNT_BM16 | BGXCNT_OVF_WRAP;
    1.35 +	REG_B_BG2PA = 0x100;
    1.36 +	REG_B_BG2PB = 0;
    1.37 +	REG_B_BG2PC = 0;
    1.38 +	REG_B_BG2PD = 0x100;
    1.39 +
    1.40 +	REG_VRAMCNT_A = VRAM_ENABLE;
    1.41 +	REG_VRAMCNT_C = VRAM_ENABLE | 4;
    1.42 +
    1.43 +	xorpat(bgmem, 256, 256);
    1.44 +
    1.45 +	for(i=0; i<SIN_TAB_SZ; i++) {
    1.46 +		float theta = (float)i * M_PI * 2.0 / (float)SIN_TAB_SZ;
    1.47 +		float s = sin(theta);
    1.48 +		float c = cos(theta);
    1.49 +		sintab[i] = (int32_t)(s * 65536.0);
    1.50 +		costab[i] = (int32_t)(c * 65536.0);
    1.51 +	}
    1.52 +
    1.53 +	ds3_clear_color(RGB15(4, 4, 4), 31);
    1.54 +	ds3_clear_depth(0x7fff);
    1.55 +	ds3_viewport(0, 0, 256, 192);
    1.56 +
    1.57 +	ds3_enable(DS3_ANTIALIAS);
    1.58 +
    1.59 +	REG_POLYGON_ATTR = 0x001f00c0;	/* alpha = 31, cull none */
    1.60 +
    1.61 +	ds3_matrix_mode(DS3_PROJECTION);
    1.62 +	ds3_load_identity();
    1.63 +	ds3_scale(49152, 65536, 65536);
    1.64 +
    1.65 +	for(;;) {
    1.66 +		int idx = frame & 0xff;
    1.67 +		int32_t scale = (sintab[(frame >> 1) & 0xff] >> 9) + 204;
    1.68 +		int32_t sa = ((sintab[idx] >> 8) * scale) >> 8;
    1.69 +		int32_t ca = ((costab[idx] >> 8) * scale) >> 8;
    1.70 +		/*float scale = 0.5 * sin(t * 0.8) + 0.8;
    1.71 +		int32_t sa = (int16_t)(sin(t) * 256 * scale);
    1.72 +		int32_t ca = (int16_t)(cos(t) * 256 * scale);
    1.73 +		*/
    1.74 +
    1.75 +		int32_t x = ca * -128 + sa * -96 + (128 << 8);
    1.76 +		int32_t y = -sa * -128 + ca * -96 + (96 << 8);
    1.77 +
    1.78 +		m[0] = ca << 8; m[1] = sa << 8;
    1.79 +		m[4] = -sa << 8; m[5] = ca << 8;
    1.80 +
    1.81 +		ds3_matrix_mode(DS3_MODELVIEW);
    1.82 +		ds3_load_matrix(m);
    1.83 +
    1.84 +		ds3_begin(DS3_QUADS);
    1.85 +		ds3_color(RGB15(31, 0, 0));
    1.86 +		ds3_vertex3(-0x8000, -0x8000, 0);
    1.87 +		ds3_color(RGB15(0, 31, 0));
    1.88 +		ds3_vertex3(0x8000, -0x8000, 0);
    1.89 +		ds3_color(RGB15(0, 0, 31));
    1.90 +		ds3_vertex3(0x8000, 0x8000, 0);
    1.91 +		ds3_color(RGB15(31, 0, 31));
    1.92 +		ds3_vertex3(-0x8000, 0x8000, 0);
    1.93 +		ds3_end();
    1.94 +
    1.95 +		ds3_swap_buffers();
    1.96 +		while(REG_VCOUNT < 192);
    1.97 +
    1.98 +		REG_B_BG2PA = ca;
    1.99 +		REG_B_BG2PB = sa;
   1.100 +		REG_B_BG2PC = -sa;
   1.101 +		REG_B_BG2PD = ca;
   1.102 +		REG_B_BG2X = x;
   1.103 +		REG_B_BG2Y = y;
   1.104 +
   1.105 +		++frame;
   1.106 +	}
   1.107 +	return 0;
   1.108 +}
   1.109 +
   1.110 +static void xorpat(void *addr, int xsz, int ysz)
   1.111 +{
   1.112 +	int i, j;
   1.113 +	uint16_t *p = addr;
   1.114 +
   1.115 +	for(i=0; i<ysz; i++) {
   1.116 +		for(j=0; j<xsz; j++) {
   1.117 +			int xor = i^j;
   1.118 +			uint16_t red = xor >> 2;
   1.119 +			uint16_t green = xor >> 1;
   1.120 +			uint16_t blue = xor;
   1.121 +			*p++ = 0x8000 | red | ((green & 0x1f) << 5) | ((blue & 0x1f) << 10);
   1.122 +		}
   1.123 +	}
   1.124 +}