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All rights reserved. 5 | // 6 | // ================================================================================================ 7 | 8 | #include 9 | #include 10 | 11 | #pragma warning(disable: 4244) 12 | 13 | 14 | typedef unsigned long uint32; 15 | typedef long int32; 16 | typedef float real32; 17 | typedef unsigned char uint8; 18 | 19 | // Globals (ack) 20 | uint32 bg = 0xFFFFFF; 21 | real32 srad = 5.1f; 22 | uint32 opac = 153; 23 | uint8 *sprof = NULL; 24 | uint8 *rgbbuf = NULL; 25 | uint32 sprofsize = 0; 26 | 27 | // shadow offsets in bitmap space 28 | int32 xoff = 2; 29 | int32 yoff = 3; 30 | 31 | // offsets from bitmap to output space 32 | int32 xbitmap = 0, ybitmap = 0; 33 | 34 | // size of bitmap 35 | int32 width, height; 36 | 37 | // size of output 38 | int32 outwidth, outheight; 39 | 40 | // output state 41 | int32 outputY = 0; 42 | 43 | int32 topql, topqt, topqr, topqb; 44 | 45 | FILE *in = stdin; 46 | 47 | // ================================================================================================ 48 | // approximation to the gaussian integral [x, infty] 49 | // ================================================================================================ 50 | static inline real32 gi(real32 x) 51 | { 52 | const real32 i6 = 1.f / 6.0f; 53 | const real32 i4 = 1.f / 4.0f; 54 | const real32 i3 = 1.f / 3.0f; 55 | 56 | if (x > 1.5f) return 0.0f; 57 | if (x < -1.5f) return 1.0f; 58 | 59 | real32 x2 = x * x; 60 | real32 x3 = x2 * x; 61 | 62 | if (x > 0.5) return .5625 - ( x3 * i6 - 3 * x2 * i4 + 1.125 * x); 63 | if (x > -0.5) return 0.5 - (0.75 * x - x3 * i3); 64 | return 0.4375 + (-x3 * i6 - 3 * x2 * i4 - 1.125 * x); 65 | } 66 | 67 | static int32 UpdateProfile() 68 | { 69 | int32 size = srad * 3 + 1; 70 | int32 c = size >> 1; 71 | 72 | sprof = new uint8[size]; 73 | sprofsize = size; 74 | if (sprof == NULL) return -1; 75 | 76 | real32 invr = 1.f / srad; 77 | for (int32 x = 1; x < size; x ++) { 78 | real32 xp = (c - x) * invr; 79 | real32 gint = gi(xp); 80 | sprof[x] = 255 - int32(255.f * gint); 81 | } 82 | // unstable here! 83 | sprof[0] = 255; 84 | 85 | return 0; 86 | } 87 | 88 | char line[2048]; 89 | static char GetLine() { 90 | if (fgets(line, 2048, in)) { 91 | return line[0]; 92 | } else { 93 | return 0; 94 | } 95 | } 96 | 97 | static int32 Initialize() 98 | { 99 | uint32 ignoreme; 100 | 101 | // try to parse PPM 102 | GetLine(); if (line[0] != 'P' || line[1] != '6') return -1; 103 | while (GetLine() == '#') {} 104 | if (sscanf(line, "%d %d\n", &width, &height) != 2) return -1; 105 | while (GetLine() == '#') {} 106 | if (sscanf(line, "%d\n", &ignoreme) != 1) return -1; 107 | if (ignoreme != 255) return -1; 108 | 109 | rgbbuf = new uint8[width * 3]; 110 | if (!rgbbuf) return -1; 111 | 112 | // setup shadow based on width, height 113 | int32 sl = int(-srad * 1.5) + xoff; 114 | int32 sr = int( srad * 1.5 + width + 0.9999) + xoff; 115 | int32 st = int(-srad * 1.5) + yoff; 116 | int32 sb = int( srad * 1.5 + height + 0.9999) + yoff; 117 | 118 | if (sl < 0) { 119 | xbitmap = -sl; 120 | sr += xbitmap; 121 | sl = 0; 122 | } 123 | if (st < 0) { 124 | ybitmap = -st; 125 | sb += ybitmap; 126 | st = 0; 127 | } 128 | 129 | int32 maxx = sr - sl; 130 | int32 maxy = sb - st; 131 | int32 bitx = width + xbitmap; 132 | int32 bity = height + ybitmap; 133 | 134 | if (bitx > maxx) maxx = bitx; 135 | if (bity > maxy) maxy = bity; 136 | 137 | outwidth = maxx; 138 | outheight = maxy; 139 | 140 | printf("P6\n# Not created by the GIMP\n%d %d\n255\n", outwidth, outheight); 141 | 142 | // find top quadrant of shadow * 2 (.1 fixed point) 143 | topql = xoff + xbitmap; 144 | topqr = width + xoff + xbitmap; 145 | topqt = yoff + ybitmap; 146 | topqb = height + yoff + ybitmap; 147 | 148 | topqb = topqt + topqb; 149 | topqt += topqt; 150 | 151 | topqr = topql + topqr; 152 | topql += topql; 153 | 154 | // we've computed xbitmap, ybitmap, outwidth, outheight 155 | return UpdateProfile(); 156 | } 157 | 158 | // ================================================================================================ 159 | // multiply with black 160 | // ================================================================================================ 161 | static inline void PixelDarken(uint32 &d, const uint32 amt) 162 | { 163 | uint32 rb = d & 0xFF00FF; 164 | uint32 g = d & 0x00FF00; 165 | d &= 0xFF000000; 166 | 167 | rb = rb * amt & 0xFF00FF00; 168 | g = g * amt & 0x00FF0000; 169 | 170 | rb |= g; 171 | d |= (rb >> 8); 172 | } 173 | 174 | // scan from x0 to x1 using outputY as the scanline 175 | int32 ScanAbs(int32 x0, int32 x1) 176 | { 177 | if (x1 <= x0) return 0; 178 | 179 | int32 maxi = sprofsize - 1; 180 | 181 | int32 filll2 = x0 * 2; 182 | int32 fillr2 = x1 * 2; 183 | 184 | int32 center = (sprofsize & ~1) - 1;//(sprof.Used() & ~1) - 1; 185 | 186 | int32 w = topqr - topql - center; 187 | int32 h = topqb - topqt - center; 188 | 189 | // scan 190 | int32 y = outputY; 191 | 192 | int32 dy = abs(y * 2 - topqb) - h; 193 | int32 oy = dy >> 1; 194 | if (oy < 0) oy = 0; 195 | 196 | uint32 sh0 = sprof[oy]; 197 | 198 | sh0 = sh0 * opac >> 8; 199 | 200 | //uint32 *dp0 = dst.Pixel(x0, y); 201 | for (int32 x = filll2; x < fillr2; x += 2) { 202 | 203 | int32 dx = abs(x - topqr) - w; 204 | int32 ox = dx >> 1; 205 | if (ox < 0) ox = 0; 206 | 207 | uint32 sh = 256 - ((sprof[ox]) * sh0 >> 8); 208 | //uint32 sh = (sprof[ox]) * sh0 >> 8; 209 | 210 | uint32 dst = bg; 211 | PixelDarken(dst, sh); 212 | putchar(dst >> 16 & 0xFF); 213 | putchar(dst >> 8 & 0xFF); 214 | putchar(dst & 0xFF); 215 | } 216 | 217 | return 0; 218 | } 219 | 220 | static int32 ProcessLine() 221 | { 222 | // write a line for "outputY" 223 | if (outputY < ybitmap || outputY >= (ybitmap + height)) { 224 | // "write" 225 | // write a whole line of shadow 226 | ScanAbs(0, outwidth); 227 | } else { 228 | // "read-write" 229 | // clip and write a line of the input bitmap 230 | ScanAbs(0, xbitmap); 231 | 232 | // in case read fails, fill buffer with bg color 233 | uint8 *rgb = rgbbuf; 234 | for (int32 i = 0; i < width; i++) { 235 | rgb[0] = bg >> 16 & 0xFF; 236 | rgb[1] = bg >> 8 & 0xFF; 237 | rgb[2] = bg & 0xFF; 238 | rgb += 3; 239 | } 240 | fread(rgbbuf, 3, width, in); 241 | fwrite(rgbbuf, 3, width, stdout); 242 | ScanAbs(xbitmap + width, outwidth); 243 | } 244 | 245 | outputY ++; 246 | 247 | return 0; 248 | } 249 | 250 | 251 | // shadowrect main: 252 | // give a background color ("#FFFFFF") 253 | // give a shadow radius (5.1) 254 | // give a shadow X offset (2) 255 | // give a shadow Y offset (3) 256 | // give an opacity (0.6) 257 | 258 | int main(int argc, char **argv) 259 | { 260 | in = fopen("test.ppm", "rb"); 261 | 262 | if (argc < 1) { 263 | printf("Usage: %s [background] [radius] [xoffset] [yoffset] [%opacity]\x13", argv[0]); 264 | return -1; 265 | } 266 | 267 | switch (argc) { 268 | case 6: 269 | opac = uint32(2.56 * atof(argv[5])); 270 | case 5: 271 | yoff = atoi(argv[4]); 272 | case 4: 273 | xoff = atoi(argv[3]); 274 | case 3: 275 | srad = atof(argv[2]); 276 | case 2: 277 | if (argv[1][0] == '#') argv[1]++; 278 | bg = strtol(argv[1], NULL, 16); 279 | } 280 | 281 | if (Initialize() != 0) { 282 | fprintf(stderr, "Input is not a valid PPM\n"); 283 | return -1; // format problem 284 | } 285 | 286 | while (outputY < outheight) { 287 | ProcessLine(); 288 | } 289 | 290 | if (rgbbuf) delete rgbbuf; rgbbuf = NULL; 291 | if (sprof) delete sprof; sprof = NULL; 292 | 293 | return 0; 294 | } 295 | 296 | --------------------------------------------------------------------------------