s_linetemp.h revision 22ae633d1ea636e0e07ba044a0f8fa2195c83bc6
1 2/* 3 * Mesa 3-D graphics library 4 * Version: 5.1 5 * 6 * Copyright (C) 1999-2002 Brian Paul All Rights Reserved. 7 * 8 * Permission is hereby granted, free of charge, to any person obtaining a 9 * copy of this software and associated documentation files (the "Software"), 10 * to deal in the Software without restriction, including without limitation 11 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 12 * and/or sell copies of the Software, and to permit persons to whom the 13 * Software is furnished to do so, subject to the following conditions: 14 * 15 * The above copyright notice and this permission notice shall be included 16 * in all copies or substantial portions of the Software. 17 * 18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 21 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN 22 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 23 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 24 */ 25 26 27/* 28 * Line Rasterizer Template 29 * 30 * This file is #include'd to generate custom line rasterizers. 31 * 32 * The following macros may be defined to indicate what auxillary information 33 * must be interplated along the line: 34 * INTERP_Z - if defined, interpolate Z values 35 * INTERP_FOG - if defined, interpolate FOG values 36 * INTERP_RGBA - if defined, interpolate RGBA values 37 * INTERP_SPEC - if defined, interpolate specular RGB values 38 * INTERP_INDEX - if defined, interpolate color index values 39 * INTERP_TEX - if defined, interpolate unit 0 texcoords 40 * INTERP_MULTITEX - if defined, interpolate multi-texcoords 41 * 42 * When one can directly address pixels in the color buffer the following 43 * macros can be defined and used to directly compute pixel addresses during 44 * rasterization (see pixelPtr): 45 * PIXEL_TYPE - the datatype of a pixel (GLubyte, GLushort, GLuint) 46 * BYTES_PER_ROW - number of bytes per row in the color buffer 47 * PIXEL_ADDRESS(X,Y) - returns the address of pixel at (X,Y) where 48 * Y==0 at bottom of screen and increases upward. 49 * 50 * Similarly, for direct depth buffer access, this type is used for depth 51 * buffer addressing: 52 * DEPTH_TYPE - either GLushort or GLuint 53 * 54 * Optionally, one may provide one-time setup code 55 * SETUP_CODE - code which is to be executed once per line 56 * 57 * To actually "plot" each pixel the PLOT macro must be defined... 58 * PLOT(X,Y) - code to plot a pixel. Example: 59 * if (Z < *zPtr) { 60 * *zPtr = Z; 61 * color = pack_rgb( FixedToInt(r0), FixedToInt(g0), 62 * FixedToInt(b0) ); 63 * put_pixel( X, Y, color ); 64 * } 65 * 66 * This code was designed for the origin to be in the lower-left corner. 67 * 68 */ 69 70 71static void 72NAME( GLcontext *ctx, const SWvertex *vert0, const SWvertex *vert1 ) 73{ 74 struct sw_span span; 75 GLuint interpFlags = 0; 76 GLint x0 = (GLint) vert0->win[0]; 77 GLint x1 = (GLint) vert1->win[0]; 78 GLint y0 = (GLint) vert0->win[1]; 79 GLint y1 = (GLint) vert1->win[1]; 80 GLint dx, dy; 81 GLint numPixels; 82 GLint xstep, ystep; 83#if defined(DEPTH_TYPE) 84 const GLint depthBits = ctx->Visual.depthBits; 85 const GLint fixedToDepthShift = depthBits <= 16 ? FIXED_SHIFT : 0; 86#define FixedToDepth(F) ((F) >> fixedToDepthShift) 87 GLint zPtrXstep, zPtrYstep; 88 DEPTH_TYPE *zPtr; 89#elif defined(INTERP_Z) 90 const GLint depthBits = ctx->Visual.depthBits; 91#endif 92#ifdef PIXEL_ADDRESS 93 PIXEL_TYPE *pixelPtr; 94 GLint pixelXstep, pixelYstep; 95#endif 96 97#ifdef SETUP_CODE 98 SETUP_CODE 99#endif 100 101 /* Cull primitives with malformed coordinates. 102 */ 103 { 104 GLfloat tmp = vert0->win[0] + vert0->win[1] 105 + vert1->win[0] + vert1->win[1]; 106 if (IS_INF_OR_NAN(tmp)) 107 return; 108 } 109 110 /* 111 printf("%s():\n", __FUNCTION__); 112 printf(" (%f, %f, %f) -> (%f, %f, %f)\n", 113 vert0->win[0], vert0->win[1], vert0->win[2], 114 vert1->win[0], vert1->win[1], vert1->win[2]); 115 printf(" (%d, %d, %d) -> (%d, %d, %d)\n", 116 vert0->color[0], vert0->color[1], vert0->color[2], 117 vert1->color[0], vert1->color[1], vert1->color[2]); 118 printf(" (%d, %d, %d) -> (%d, %d, %d)\n", 119 vert0->specular[0], vert0->specular[1], vert0->specular[2], 120 vert1->specular[0], vert1->specular[1], vert1->specular[2]); 121 */ 122 123/* 124 * Despite being clipped to the view volume, the line's window coordinates 125 * may just lie outside the window bounds. That is, if the legal window 126 * coordinates are [0,W-1][0,H-1], it's possible for x==W and/or y==H. 127 * This quick and dirty code nudges the endpoints inside the window if 128 * necessary. 129 */ 130#ifdef CLIP_HACK 131 { 132 GLint w = ctx->DrawBuffer->Width; 133 GLint h = ctx->DrawBuffer->Height; 134 if ((x0==w) | (x1==w)) { 135 if ((x0==w) & (x1==w)) 136 return; 137 x0 -= x0==w; 138 x1 -= x1==w; 139 } 140 if ((y0==h) | (y1==h)) { 141 if ((y0==h) & (y1==h)) 142 return; 143 y0 -= y0==h; 144 y1 -= y1==h; 145 } 146 } 147#endif 148 149 dx = x1 - x0; 150 dy = y1 - y0; 151 if (dx == 0 && dy == 0) 152 return; 153 154#ifdef DEPTH_TYPE 155 zPtr = (DEPTH_TYPE *) _swrast_zbuffer_address(ctx, x0, y0); 156#endif 157#ifdef PIXEL_ADDRESS 158 pixelPtr = (PIXEL_TYPE *) PIXEL_ADDRESS(x0,y0); 159#endif 160 161 if (dx<0) { 162 dx = -dx; /* make positive */ 163 xstep = -1; 164#ifdef DEPTH_TYPE 165 zPtrXstep = -((GLint)sizeof(DEPTH_TYPE)); 166#endif 167#ifdef PIXEL_ADDRESS 168 pixelXstep = -((GLint)sizeof(PIXEL_TYPE)); 169#endif 170 } 171 else { 172 xstep = 1; 173#ifdef DEPTH_TYPE 174 zPtrXstep = ((GLint)sizeof(DEPTH_TYPE)); 175#endif 176#ifdef PIXEL_ADDRESS 177 pixelXstep = ((GLint)sizeof(PIXEL_TYPE)); 178#endif 179 } 180 181 if (dy<0) { 182 dy = -dy; /* make positive */ 183 ystep = -1; 184#ifdef DEPTH_TYPE 185 zPtrYstep = -((GLint) (ctx->DrawBuffer->Width * sizeof(DEPTH_TYPE))); 186#endif 187#ifdef PIXEL_ADDRESS 188 pixelYstep = BYTES_PER_ROW; 189#endif 190 } 191 else { 192 ystep = 1; 193#ifdef DEPTH_TYPE 194 zPtrYstep = (GLint) (ctx->DrawBuffer->Width * sizeof(DEPTH_TYPE)); 195#endif 196#ifdef PIXEL_ADDRESS 197 pixelYstep = -(BYTES_PER_ROW); 198#endif 199 } 200 201 ASSERT(dx >= 0); 202 ASSERT(dy >= 0); 203 204 numPixels = MAX2(dx, dy); 205 206 /* 207 * Span setup: compute start and step values for all interpolated values. 208 */ 209#ifdef INTERP_RGBA 210 interpFlags |= SPAN_RGBA; 211 if (ctx->Light.ShadeModel == GL_SMOOTH) { 212 span.red = ChanToFixed(vert0->color[0]); 213 span.green = ChanToFixed(vert0->color[1]); 214 span.blue = ChanToFixed(vert0->color[2]); 215 span.alpha = ChanToFixed(vert0->color[3]); 216 span.redStep = (ChanToFixed(vert1->color[0]) - span.red ) / numPixels; 217 span.greenStep = (ChanToFixed(vert1->color[1]) - span.green) / numPixels; 218 span.blueStep = (ChanToFixed(vert1->color[2]) - span.blue ) / numPixels; 219 span.alphaStep = (ChanToFixed(vert1->color[3]) - span.alpha) / numPixels; 220 } 221 else { 222 span.red = ChanToFixed(vert1->color[0]); 223 span.green = ChanToFixed(vert1->color[1]); 224 span.blue = ChanToFixed(vert1->color[2]); 225 span.alpha = ChanToFixed(vert1->color[3]); 226 span.redStep = 0; 227 span.greenStep = 0; 228 span.blueStep = 0; 229 span.alphaStep = 0; 230 } 231#endif 232#ifdef INTERP_SPEC 233 interpFlags |= SPAN_SPEC; 234 if (ctx->Light.ShadeModel == GL_SMOOTH) { 235 span.specRed = ChanToFixed(vert0->specular[0]); 236 span.specGreen = ChanToFixed(vert0->specular[1]); 237 span.specBlue = ChanToFixed(vert0->specular[2]); 238 span.specRedStep = (ChanToFixed(vert1->specular[0]) - span.specRed) / numPixels; 239 span.specGreenStep = (ChanToFixed(vert1->specular[1]) - span.specBlue) / numPixels; 240 span.specBlueStep = (ChanToFixed(vert1->specular[2]) - span.specGreen) / numPixels; 241 } 242 else { 243 span.specRed = ChanToFixed(vert1->specular[0]); 244 span.specGreen = ChanToFixed(vert1->specular[1]); 245 span.specBlue = ChanToFixed(vert1->specular[2]); 246 span.specRedStep = 0; 247 span.specGreenStep = 0; 248 span.specBlueStep = 0; 249 } 250#endif 251#ifdef INTERP_INDEX 252 interpFlags |= SPAN_INDEX; 253 if (ctx->Light.ShadeModel == GL_SMOOTH) { 254 span.index = FloatToFixed(vert0->index); 255 span.indexStep = FloatToFixed(vert1->index - vert0->index) / numPixels; 256 } 257 else { 258 span.index = FloatToFixed(vert1->index); 259 span.indexStep = 0; 260 } 261#endif 262#if defined(INTERP_Z) || defined(DEPTH_TYPE) 263 interpFlags |= SPAN_Z; 264 { 265 if (depthBits <= 16) { 266 span.z = FloatToFixed(vert0->win[2]) + FIXED_HALF; 267 span.zStep = FloatToFixed(vert1->win[2] - vert0->win[2]) / numPixels; 268 } 269 else { 270 /* don't use fixed point */ 271 span.z = (GLint) vert0->win[2]; 272 span.zStep = (GLint) ((vert1->win[2] - vert0->win[2]) / numPixels); 273 } 274 } 275#endif 276#ifdef INTERP_FOG 277 interpFlags |= SPAN_FOG; 278 span.fog = vert0->fog; 279 span.fogStep = (vert1->fog - vert0->fog) / numPixels; 280#endif 281#ifdef INTERP_TEX 282 interpFlags |= SPAN_TEXTURE; 283 { 284 const GLfloat invw0 = vert0->win[3]; 285 const GLfloat invw1 = vert1->win[3]; 286 const GLfloat invLen = 1.0F / numPixels; 287 GLfloat ds, dt, dr, dq; 288 span.tex[0][0] = invw0 * vert0->texcoord[0][0]; 289 span.tex[0][1] = invw0 * vert0->texcoord[0][1]; 290 span.tex[0][2] = invw0 * vert0->texcoord[0][2]; 291 span.tex[0][3] = invw0 * vert0->texcoord[0][3]; 292 ds = (invw1 * vert1->texcoord[0][0]) - span.tex[0][0]; 293 dt = (invw1 * vert1->texcoord[0][1]) - span.tex[0][1]; 294 dr = (invw1 * vert1->texcoord[0][2]) - span.tex[0][2]; 295 dq = (invw1 * vert1->texcoord[0][3]) - span.tex[0][3]; 296 span.texStepX[0][0] = ds * invLen; 297 span.texStepX[0][1] = dt * invLen; 298 span.texStepX[0][2] = dr * invLen; 299 span.texStepX[0][3] = dq * invLen; 300 span.texStepY[0][0] = 0.0F; 301 span.texStepY[0][1] = 0.0F; 302 span.texStepY[0][2] = 0.0F; 303 span.texStepY[0][3] = 0.0F; 304 } 305#endif 306#ifdef INTERP_MULTITEX 307 interpFlags |= SPAN_TEXTURE; 308 { 309 const GLfloat invLen = 1.0F / numPixels; 310 GLuint u; 311 for (u = 0; u < ctx->Const.MaxTextureUnits; u++) { 312 if (ctx->Texture.Unit[u]._ReallyEnabled) { 313 const GLfloat invw0 = vert0->win[3]; 314 const GLfloat invw1 = vert1->win[3]; 315 GLfloat ds, dt, dr, dq; 316 span.tex[u][0] = invw0 * vert0->texcoord[u][0]; 317 span.tex[u][1] = invw0 * vert0->texcoord[u][1]; 318 span.tex[u][2] = invw0 * vert0->texcoord[u][2]; 319 span.tex[u][3] = invw0 * vert0->texcoord[u][3]; 320 ds = (invw1 * vert1->texcoord[u][0]) - span.tex[u][0]; 321 dt = (invw1 * vert1->texcoord[u][1]) - span.tex[u][1]; 322 dr = (invw1 * vert1->texcoord[u][2]) - span.tex[u][2]; 323 dq = (invw1 * vert1->texcoord[u][3]) - span.tex[u][3]; 324 span.texStepX[u][0] = ds * invLen; 325 span.texStepX[u][1] = dt * invLen; 326 span.texStepX[u][2] = dr * invLen; 327 span.texStepX[u][3] = dq * invLen; 328 span.texStepY[u][0] = 0.0F; 329 span.texStepY[u][1] = 0.0F; 330 span.texStepY[u][2] = 0.0F; 331 span.texStepY[u][3] = 0.0F; 332 } 333 } 334 } 335#endif 336 337 INIT_SPAN(span, GL_LINE, numPixels, interpFlags, SPAN_XY); 338 339 /* 340 * Draw 341 */ 342 343 if (dx > dy) { 344 /*** X-major line ***/ 345 GLint i; 346 GLint errorInc = dy+dy; 347 GLint error = errorInc-dx; 348 GLint errorDec = error-dx; 349 350 for (i = 0; i < dx; i++) { 351#ifdef DEPTH_TYPE 352 GLdepth Z = FixedToDepth(span.z); 353#endif 354#ifdef PLOT 355 PLOT( x0, y0 ); 356#else 357 span.array->x[i] = x0; 358 span.array->y[i] = y0; 359#endif 360 x0 += xstep; 361#ifdef DEPTH_TYPE 362 zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrXstep); 363 span.z += span.zStep; 364#endif 365#ifdef PIXEL_ADDRESS 366 pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelXstep); 367#endif 368 if (error<0) { 369 error += errorInc; 370 } 371 else { 372 error += errorDec; 373 y0 += ystep; 374#ifdef DEPTH_TYPE 375 zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrYstep); 376#endif 377#ifdef PIXEL_ADDRESS 378 pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelYstep); 379#endif 380 } 381 } 382 } 383 else { 384 /*** Y-major line ***/ 385 GLint i; 386 GLint errorInc = dx+dx; 387 GLint error = errorInc-dy; 388 GLint errorDec = error-dy; 389 390 for (i=0;i<dy;i++) { 391#ifdef DEPTH_TYPE 392 GLdepth Z = FixedToDepth(span.z); 393#endif 394#ifdef PLOT 395 PLOT( x0, y0 ); 396#else 397 span.array->x[i] = x0; 398 span.array->y[i] = y0; 399#endif 400 y0 += ystep; 401#ifdef DEPTH_TYPE 402 zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrYstep); 403 span.z += span.zStep; 404#endif 405#ifdef PIXEL_ADDRESS 406 pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelYstep); 407#endif 408 if (error<0) { 409 error += errorInc; 410 } 411 else { 412 error += errorDec; 413 x0 += xstep; 414#ifdef DEPTH_TYPE 415 zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrXstep); 416#endif 417#ifdef PIXEL_ADDRESS 418 pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelXstep); 419#endif 420 } 421 } 422 } 423 424#ifdef RENDER_SPAN 425 RENDER_SPAN( span ); 426#endif 427 428 (void)span; 429 430} 431 432 433#undef NAME 434#undef INTERP_Z 435#undef INTERP_FOG 436#undef INTERP_RGBA 437#undef INTERP_SPEC 438#undef INTERP_TEX 439#undef INTERP_MULTITEX 440#undef INTERP_INDEX 441#undef PIXEL_ADDRESS 442#undef PIXEL_TYPE 443#undef DEPTH_TYPE 444#undef BYTES_PER_ROW 445#undef SETUP_CODE 446#undef PLOT 447#undef CLIP_HACK 448#undef FixedToDepth 449#undef RENDER_SPAN 450