[673] | 1 | #include "disp.h" |
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| 2 | #include "game.h" |
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| 3 | #include <stdio.h> |
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| 4 | #include <stdlib.h> |
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[676] | 5 | #include <malloc.h> |
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[673] | 6 | #include <math.h> |
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| 7 | #include <hard_config.h> |
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| 8 | |
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| 9 | #define FIELD_OF_VIEW (70.f * M_PI / 180.f) // Camera field of view |
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| 10 | #define TEX_SIZE (32) // Texture size in pixels |
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| 11 | #define CEILING_COLOR (0xBB) // lite gray |
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| 12 | #define FLOOR_COLOR (0x33) // dark gray |
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| 13 | |
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| 14 | // Globals |
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| 15 | |
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[679] | 16 | static unsigned char* buf[2]; |
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| 17 | static void * sts[2]; |
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| 18 | static unsigned int cur_buf; |
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[673] | 19 | |
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| 20 | // Textures indexed by block number |
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[676] | 21 | static unsigned char *g_tex[] = |
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[673] | 22 | { |
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| 23 | NULL, // 0 |
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[676] | 24 | NULL, // rock |
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| 25 | NULL, // door |
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| 26 | NULL, // handle |
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| 27 | NULL, // wood |
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[673] | 28 | }; |
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| 29 | |
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| 30 | // Local functions |
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| 31 | |
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[677] | 32 | static void dispDrawColumnTex(int x, int y0, int y1, unsigned char *tex, int tx) |
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[673] | 33 | { |
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[677] | 34 | int y; |
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[673] | 35 | |
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[677] | 36 | if (x < 0 || x >= FBUF_X_SIZE) |
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| 37 | return; |
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[673] | 38 | |
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[677] | 39 | for (y = y0; y < y1 && y < FBUF_Y_SIZE; y++) { |
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| 40 | if (y < 0) |
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| 41 | y = 0; |
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[673] | 42 | |
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[677] | 43 | int ty = (y - y0) * TEX_SIZE / (y1 - y0); |
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| 44 | |
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[679] | 45 | buf[cur_buf][y * FBUF_X_SIZE + x] = tex[ty * TEX_SIZE + tx]; |
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[677] | 46 | } |
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[673] | 47 | } |
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| 48 | |
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[677] | 49 | static void dispDrawColumnSolid(int x, int y0, int y1, unsigned char color) |
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[673] | 50 | { |
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[677] | 51 | int y; |
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| 52 | |
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| 53 | if (x < 0 || x >= FBUF_X_SIZE) |
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| 54 | return; |
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| 55 | |
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| 56 | for (y = y0; y < y1 && y < FBUF_Y_SIZE; y++) { |
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| 57 | if (y < 0) |
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| 58 | y = 0; |
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| 59 | |
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[679] | 60 | buf[cur_buf][y * FBUF_X_SIZE + x] = color; |
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[677] | 61 | } |
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| 62 | } |
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| 63 | |
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| 64 | static void dispDrawSlice(Game *game, int x, int height, int type, float tx) |
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| 65 | { |
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[673] | 66 | // Ceiling |
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[677] | 67 | dispDrawColumnSolid(x, |
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| 68 | 0, |
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| 69 | (FBUF_Y_SIZE - height) / 2, |
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| 70 | CEILING_COLOR); |
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[673] | 71 | |
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| 72 | // Wall |
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[676] | 73 | unsigned char *tex = g_tex[type]; |
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[673] | 74 | |
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| 75 | if (tex) { |
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| 76 | // Draw a texture slice |
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[677] | 77 | dispDrawColumnTex(x, |
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| 78 | (FBUF_Y_SIZE - height) / 2, |
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| 79 | (FBUF_Y_SIZE + height) / 2, |
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| 80 | tex, |
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| 81 | (int)(tx * TEX_SIZE)); |
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[673] | 82 | } |
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| 83 | else { |
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| 84 | // Draw a solid color slice |
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[677] | 85 | dispDrawColumnSolid(x, |
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| 86 | (FBUF_Y_SIZE - height) / 2, |
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| 87 | (FBUF_Y_SIZE + height) / 2, |
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| 88 | 0xFF); |
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[673] | 89 | } |
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| 90 | |
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| 91 | // Floor |
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[677] | 92 | dispDrawColumnSolid(x, |
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| 93 | (FBUF_Y_SIZE + height) / 2, |
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| 94 | FBUF_Y_SIZE, |
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| 95 | FLOOR_COLOR); |
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[673] | 96 | } |
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| 97 | |
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| 98 | static float dispRaycast(Game *game, int *type, float *tx, float angle) |
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| 99 | { |
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| 100 | float x = game->player.x; |
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| 101 | float y = game->player.y; |
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| 102 | |
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| 103 | // Camera is inside a block. |
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| 104 | // Return a minimal distance to avoid a division by zero. |
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| 105 | if ((gameLocate(floor(x), floor(y))) != 0) { |
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| 106 | *type = 0; |
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| 107 | *tx = 0.f; |
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| 108 | return 0.0001f; |
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| 109 | } |
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| 110 | |
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| 111 | // Precompute |
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| 112 | float vsin = sin(angle); |
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| 113 | float vcos = cos(angle); |
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| 114 | float vtan = vsin / vcos; |
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| 115 | |
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| 116 | // Calculate increments |
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| 117 | int incix = (vcos > 0.f) - (vcos < 0.f); |
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| 118 | int inciy = (vsin > 0.f) - (vsin < 0.f); |
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| 119 | float incfx = inciy / vtan; |
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| 120 | float incfy = incix * vtan; |
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| 121 | |
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| 122 | // Calculate start position |
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| 123 | int ix = floor(x) + (incix > 0); |
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| 124 | int iy = floor(y) + (inciy > 0); |
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| 125 | float fx = x + incfx * fabs(floor(y) + (inciy > 0) - y); |
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| 126 | float fy = y + incfy * fabs(floor(x) + (incix > 0) - x); |
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| 127 | |
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| 128 | // Find the first colliding tile in each direction |
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| 129 | while (incix && gameLocate(ix - (incix < 0), fy) == 0) |
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| 130 | { |
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| 131 | ix += incix; |
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| 132 | fy += incfy; |
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| 133 | } |
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| 134 | while (inciy && gameLocate(fx, iy - (inciy < 0)) == 0) |
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| 135 | { |
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| 136 | fx += incfx; |
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| 137 | iy += inciy; |
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| 138 | } |
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| 139 | |
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| 140 | // Find the shortest ray |
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| 141 | float dx = (incix) ? ((ix - x) / vcos) : 0xFFFF; |
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| 142 | float dy = (inciy) ? ((iy - y) / vsin) : 0xFFFF; |
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| 143 | |
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| 144 | if (dx < dy) |
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| 145 | { |
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| 146 | // Get block type |
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| 147 | *type = gameLocate(ix - (incix < 0), floor(fy)); |
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| 148 | |
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| 149 | // Get wall texture coordinate [0;1] |
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| 150 | *tx = fy - floor(fy); |
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| 151 | if (incix < 0) |
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| 152 | *tx = 1 - *tx; |
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| 153 | |
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| 154 | return dx; |
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| 155 | } |
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| 156 | else |
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| 157 | { |
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| 158 | // Get block type |
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| 159 | *type = gameLocate(floor(fx), iy - (inciy < 0)); |
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| 160 | |
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| 161 | // Get wall texture coordinate [0;1] |
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| 162 | *tx = fx - floor(fx); |
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| 163 | if (inciy > 0) |
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| 164 | *tx = 1 - *tx; |
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| 165 | |
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| 166 | return dy; |
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| 167 | } |
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| 168 | } |
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| 169 | |
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[677] | 170 | static unsigned char *loadTexture(char *path) |
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[676] | 171 | { |
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| 172 | int fd; |
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| 173 | unsigned char *tex; |
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| 174 | |
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| 175 | tex = malloc(TEX_SIZE * TEX_SIZE); |
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| 176 | fd = giet_fat_open(path, O_RDONLY); |
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| 177 | if (fd < 0) { |
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| 178 | free(tex); |
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| 179 | return NULL; |
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| 180 | } |
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| 181 | |
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[677] | 182 | giet_fat_read(fd, tex, TEX_SIZE * TEX_SIZE); |
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[676] | 183 | giet_fat_close(fd); |
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| 184 | giet_tty_printf("[RAYCAST] loaded tex %s\n", path); |
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| 185 | |
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| 186 | return tex; |
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| 187 | } |
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| 188 | |
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[673] | 189 | // Exported functions |
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| 190 | |
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| 191 | void dispInit() |
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| 192 | { |
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[679] | 193 | // allocate framebuffer |
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| 194 | buf[0] = almalloc(64, FBUF_X_SIZE * FBUF_Y_SIZE); |
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| 195 | buf[1] = almalloc(64, FBUF_X_SIZE * FBUF_Y_SIZE); |
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| 196 | sts[0] = almalloc(64, 64); |
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| 197 | sts[1] = almalloc(64, 64); |
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| 198 | |
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[676] | 199 | // initialize framebuffer |
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[673] | 200 | giet_fbf_cma_alloc(); |
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[679] | 201 | giet_fbf_cma_init_buf(buf[0], buf[1], sts[0], sts[1]); |
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[673] | 202 | giet_fbf_cma_start(FBUF_X_SIZE * FBUF_Y_SIZE); |
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| 203 | |
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[676] | 204 | // load textures |
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| 205 | g_tex[1] = loadTexture("misc/rock_32.raw"); |
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| 206 | g_tex[2] = loadTexture("misc/door_32.raw"); |
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| 207 | g_tex[3] = loadTexture("misc/handle_32.raw"); |
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| 208 | g_tex[4] = loadTexture("misc/wood_32.raw"); |
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| 209 | |
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[677] | 210 | cur_buf = 0; |
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[673] | 211 | } |
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| 212 | |
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| 213 | void dispRender(Game *game) |
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| 214 | { |
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[677] | 215 | int start = giet_proctime(); |
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[673] | 216 | float angle = game->player.dir - FIELD_OF_VIEW / 2.f; |
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| 217 | |
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| 218 | // Cast a ray for each pixel column and draw a colored wall slice |
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| 219 | for (int i = 0; i < FBUF_X_SIZE; i++) |
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| 220 | { |
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| 221 | float dist; |
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| 222 | int type; |
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| 223 | float tx; |
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| 224 | |
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| 225 | // Cast a ray to get wall distance |
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| 226 | dist = dispRaycast(game, &type, &tx, angle); |
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| 227 | |
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| 228 | // Perspective correction |
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| 229 | dist *= cos(game->player.dir - angle); |
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| 230 | |
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| 231 | // Draw ceiling, wall and floor |
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[677] | 232 | dispDrawSlice(game, i, FBUF_Y_SIZE / dist, type, tx); |
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[673] | 233 | |
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| 234 | angle += FIELD_OF_VIEW / FBUF_X_SIZE; |
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| 235 | } |
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| 236 | |
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[677] | 237 | giet_fbf_cma_display(cur_buf); |
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| 238 | cur_buf = !cur_buf; |
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| 239 | giet_tty_printf("[RAYCAST] flip (took %d cycles)\n", giet_proctime() - start); |
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[673] | 240 | } |
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