correct tunnel curving
[gbajam21] / src / gamescr.c
1 #include <stdlib.h>
2 #include <string.h>
3 #include "gbaregs.h"
4 #include "game.h"
5 #include "dma.h"
6 #include "data.h"
7 #include "util.h"
8 #include "intr.h"
9 #include "input.h"
10 #include "sprite.h"
11 #include "debug.h"
12
13 static void draw_tunnel(void);
14 static void vblank(void);
15
16 static int nframes, backbuf;
17 static uint16_t *vram[] = { (uint16_t*)VRAM_LFB_FB0_ADDR, (uint16_t*)VRAM_LFB_FB1_ADDR };
18 static unsigned char *tex;
19 static uint16_t bnstate;
20
21 #define MAX_SPR         4
22 static uint16_t oam[4 * MAX_SPR];
23
24 static short x = 120, y = 80;
25 static unsigned char rot;
26
27 static int32_t bgmat[4];
28 static int32_t bgx, bgy;
29 static int32_t tunrot;
30
31 void gamescr(void)
32 {
33         int i;
34         uint16_t *cdst;
35         unsigned char *csrc;
36
37         REG_DISPCNT = 4 | DISPCNT_BG2 | DISPCNT_OBJ | DISPCNT_FB1;
38
39         vblperf_setcolor(0xff);
40
41         /* sprite setup */
42         spr_setup(16, 16, spr_game_pixels, spr_game_cmap);
43
44         wait_vblank();
45         spr_clear();
46         spr_oam_clear(oam, 0);
47         spr_oam_clear(oam, 1);
48         spr_oam_clear(oam, 2);
49         spr_oam_clear(oam, 3);
50
51         cdst = (uint16_t*)CRAM_BG_ADDR;
52         csrc = tuncross_cmap;
53         for(i=0; i<256; i++) {
54                 *cdst++ = CONV_RGB24_RGB15(csrc[0], csrc[1], csrc[2]);
55                 csrc += 3;
56         }
57
58         fillblock_16byte(vram[0], 0xffffffff, 240 * 160 / 16);
59         fillblock_16byte(vram[1], 0xffffffff, 240 * 160 / 16);
60
61         tex = iwram_sbrk(32 * 32);
62         memcpy(tex, tuncross_pixels, 32 * 32);
63
64         /*select_input(BN_DPAD);*/
65
66         mask(INTR_VBLANK);
67         screen_vblank = vblank;
68         unmask(INTR_VBLANK);
69
70         nframes = 0;
71         for(;;) {
72                 backbuf = ++nframes & 1;
73
74                 bnstate = ~REG_KEYINPUT;
75
76                 draw_tunnel();
77
78                 vblperf_end();
79                 wait_vblank();
80                 present(backbuf);
81                 vblperf_begin();
82         }
83 }
84
85 __attribute__((noinline, target("arm"), section(".iwram")))
86 static void draw_tunnel(void)
87 {
88         int i, j, tx, ty, angle, depth, zoffs, uoffs, flip, tunturn;
89         static int tunsweep;
90         uint16_t pptop, ppbot;
91         uint16_t *top, *bot;
92         uint32_t tun, *tunptr;
93
94         //tunsweep = SIN(nframes) >> 4;
95
96         if((bnstate & BN_RT) && tunsweep > -31) tunsweep--;
97         if((bnstate & BN_LT) && tunsweep < 31) tunsweep++;
98
99         flip = tunsweep < 0;
100         tunturn = abs(tunsweep) & 0x1f;
101
102         zoffs = nframes;
103
104         uoffs = flip ? -nframes : nframes;
105
106         top = vram[backbuf];
107         bot = vram[backbuf] + 159 * 240 / 2;
108         tunptr = tunmap + tunturn * 9600;
109
110         if(flip) {
111                 tunptr += 240/2;
112                 for(i=0; i<80; i++) {
113                         for(j=0; j<240/2; j++) {
114                                 tun = *--tunptr;
115                                 tun = (tun >> 16) | (tun << 16);
116
117                                 angle = tun & 0xff;
118                                 depth = (tun >> 8) & 0xff;
119                                 tx = ~((angle >> 1) - uoffs) & 0x1f;
120                                 ty = ((depth >> 1) + zoffs) & 0x1f;
121                                 pptop = tex[(ty << 5) + tx];
122                                 tx = ((angle >> 1) + uoffs) & 0x1f;
123                                 ppbot = tex[(ty << 5) + tx];
124
125                                 angle = (tun >> 16) & 0xff;
126                                 depth = (tun >> 24) & 0xff;
127                                 tx = ~((angle >> 1) - uoffs) & 0x1f;
128                                 ty = ((depth >> 1) + zoffs) & 0x1f;
129                                 pptop |= (uint16_t)tex[(ty << 5) + tx] << 8;
130                                 tx = ((angle >> 1) + uoffs) & 0x1f;
131                                 ppbot |= (uint16_t)tex[(ty << 5) + tx] << 8;
132
133                                 *top++ = pptop;
134                                 *bot++ = ppbot;
135                         }
136                         bot -= 240;
137                         tunptr += 240;
138                 }
139         } else {
140                 for(i=0; i<80; i++) {
141                         for(j=0; j<240/2; j++) {
142                                 tun = *tunptr++;
143
144                                 angle = tun & 0xff;
145                                 depth = (tun >> 8) & 0xff;
146                                 tx = ((angle >> 1) - uoffs) & 0x1f;
147                                 ty = ((depth >> 1) + zoffs) & 0x1f;
148                                 pptop = tex[(ty << 5) + tx];
149                                 tx = ~((angle >> 1) + uoffs) & 0x1f;
150                                 ppbot = tex[(ty << 5) + tx];
151
152                                 angle = (tun >> 16) & 0xff;
153                                 depth = (tun >> 24) & 0xff;
154                                 tx = ((angle >> 1) - uoffs) & 0x1f;
155                                 ty = ((depth >> 1) + zoffs) & 0x1f;
156                                 pptop |= (uint16_t)tex[(ty << 5) + tx] << 8;
157                                 tx = ~((angle >> 1) + uoffs) & 0x1f;
158                                 ppbot |= (uint16_t)tex[(ty << 5) + tx] << 8;
159
160                                 *top++ = pptop;
161                                 *bot++ = ppbot;
162                         }
163                         bot -= 240;
164                 }
165         }
166 }
167
168 __attribute__((noinline, target("arm"), section(".iwram")))
169 static void vblank(void)
170 {
171         uint16_t bnstate;
172         int16_t mat[4];
173         static short gate_speed;
174
175         bnstate = ~REG_KEYINPUT;
176         if(bnstate & BN_DPAD) {
177                 if(gate_speed < 5) {
178                         gate_speed++;
179                 }
180
181                 if(bnstate & BN_LEFT) x -= gate_speed;
182                 if(bnstate & BN_RIGHT) x += gate_speed;
183                 if(bnstate & BN_UP) y -= gate_speed;
184                 if(bnstate & BN_DOWN) y += gate_speed;
185
186                 if(x < 0) x = 0;
187                 if(x > 239) x = 239;
188                 if(y < 0) y = 0;
189                 if(y > 159) y = 159;
190         } else {
191                 gate_speed = 0;
192         }
193
194         if(bnstate & BN_A) rot -= 2;
195         if(bnstate & BN_B) rot += 2;
196
197
198         spr_oam(oam, 0, 512 + 256, x - 64, y - 64, SPR_256COL | SPR_SZ64 | SPR_DBLSZ |
199                         SPR_ROTSCL | SPR_ROTSCL_SEL(0));
200
201         mat[0] = COS(rot);
202         mat[1] = -SIN(rot);
203         mat[2] = SIN(rot);
204         mat[3] = COS(rot);
205         spr_transform(oam, 0, mat);
206
207
208         dma_copy16(3, (void*)OAM_ADDR, oam, sizeof oam / 2, 0);
209 }