s_linetemp.h revision 69a5896238c3553422fcf80feebe5fa39e636006
1/* 2 * Mesa 3-D graphics library 3 * Version: 6.3 4 * 5 * Copyright (C) 1999-2004 Brian Paul All Rights Reserved. 6 * 7 * Permission is hereby granted, free of charge, to any person obtaining a 8 * copy of this software and associated documentation files (the "Software"), 9 * to deal in the Software without restriction, including without limitation 10 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 11 * and/or sell copies of the Software, and to permit persons to whom the 12 * Software is furnished to do so, subject to the following conditions: 13 * 14 * The above copyright notice and this permission notice shall be included 15 * in all copies or substantial portions of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 20 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN 21 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 23 */ 24 25 26/* 27 * Line Rasterizer Template 28 * 29 * This file is #include'd to generate custom line rasterizers. 30 * 31 * The following macros may be defined to indicate what auxillary information 32 * must be interplated along the line: 33 * INTERP_Z - if defined, interpolate Z values 34 * INTERP_FOG - if defined, interpolate FOG values 35 * INTERP_RGBA - if defined, interpolate RGBA values 36 * INTERP_SPEC - if defined, interpolate specular RGB values 37 * INTERP_INDEX - if defined, interpolate color index values 38 * INTERP_TEX - if defined, interpolate unit 0 texcoords 39 * INTERP_MULTITEX - if defined, interpolate multi-texcoords 40 * 41 * When one can directly address pixels in the color buffer the following 42 * macros can be defined and used to directly compute pixel addresses during 43 * rasterization (see pixelPtr): 44 * PIXEL_TYPE - the datatype of a pixel (GLubyte, GLushort, GLuint) 45 * BYTES_PER_ROW - number of bytes per row in the color buffer 46 * PIXEL_ADDRESS(X,Y) - returns the address of pixel at (X,Y) where 47 * Y==0 at bottom of screen and increases upward. 48 * 49 * Similarly, for direct depth buffer access, this type is used for depth 50 * buffer addressing: 51 * DEPTH_TYPE - either GLushort or GLuint 52 * 53 * Optionally, one may provide one-time setup code 54 * SETUP_CODE - code which is to be executed once per line 55 * 56 * To actually "plot" each pixel the PLOT macro must be defined... 57 * PLOT(X,Y) - code to plot a pixel. Example: 58 * if (Z < *zPtr) { 59 * *zPtr = Z; 60 * color = pack_rgb( FixedToInt(r0), FixedToInt(g0), 61 * FixedToInt(b0) ); 62 * put_pixel( X, Y, color ); 63 * } 64 * 65 * This code was designed for the origin to be in the lower-left corner. 66 * 67 */ 68 69 70static void 71NAME( GLcontext *ctx, const SWvertex *vert0, const SWvertex *vert1 ) 72{ 73 struct sw_span span; 74 GLuint interpFlags = 0; 75 GLint x0 = (GLint) vert0->win[0]; 76 GLint x1 = (GLint) vert1->win[0]; 77 GLint y0 = (GLint) vert0->win[1]; 78 GLint y1 = (GLint) vert1->win[1]; 79 GLint dx, dy; 80 GLint numPixels; 81 GLint xstep, ystep; 82#if defined(DEPTH_TYPE) 83 const GLint depthBits = ctx->Visual.depthBits; 84 const GLint fixedToDepthShift = depthBits <= 16 ? FIXED_SHIFT : 0; 85#define FixedToDepth(F) ((F) >> fixedToDepthShift) 86 GLint zPtrXstep, zPtrYstep; 87 DEPTH_TYPE *zPtr; 88#elif defined(INTERP_Z) 89 const GLint depthBits = ctx->Visual.depthBits; 90#endif 91#ifdef PIXEL_ADDRESS 92 PIXEL_TYPE *pixelPtr; 93 GLint pixelXstep, pixelYstep; 94#endif 95 96#ifdef SETUP_CODE 97 SETUP_CODE 98#endif 99 100 /* Cull primitives with malformed coordinates. 101 */ 102 { 103 GLfloat tmp = vert0->win[0] + vert0->win[1] 104 + vert1->win[0] + vert1->win[1]; 105 if (IS_INF_OR_NAN(tmp)) 106 return; 107 } 108 109 /* 110 printf("%s():\n", __FUNCTION__); 111 printf(" (%f, %f, %f) -> (%f, %f, %f)\n", 112 vert0->win[0], vert0->win[1], vert0->win[2], 113 vert1->win[0], vert1->win[1], vert1->win[2]); 114 printf(" (%d, %d, %d) -> (%d, %d, %d)\n", 115 vert0->color[0], vert0->color[1], vert0->color[2], 116 vert1->color[0], vert1->color[1], vert1->color[2]); 117 printf(" (%d, %d, %d) -> (%d, %d, %d)\n", 118 vert0->specular[0], vert0->specular[1], vert0->specular[2], 119 vert1->specular[0], vert1->specular[1], vert1->specular[2]); 120 */ 121 122/* 123 * Despite being clipped to the view volume, the line's window coordinates 124 * may just lie outside the window bounds. That is, if the legal window 125 * coordinates are [0,W-1][0,H-1], it's possible for x==W and/or y==H. 126 * This quick and dirty code nudges the endpoints inside the window if 127 * necessary. 128 */ 129#ifdef CLIP_HACK 130 { 131 GLint w = ctx->DrawBuffer->Width; 132 GLint h = ctx->DrawBuffer->Height; 133 if ((x0==w) | (x1==w)) { 134 if ((x0==w) & (x1==w)) 135 return; 136 x0 -= x0==w; 137 x1 -= x1==w; 138 } 139 if ((y0==h) | (y1==h)) { 140 if ((y0==h) & (y1==h)) 141 return; 142 y0 -= y0==h; 143 y1 -= y1==h; 144 } 145 } 146#endif 147 148 dx = x1 - x0; 149 dy = y1 - y0; 150 if (dx == 0 && dy == 0) 151 return; 152 153#ifdef DEPTH_TYPE 154 zPtr = (DEPTH_TYPE *) _swrast_zbuffer_address(ctx, x0, y0); 155#endif 156#ifdef PIXEL_ADDRESS 157 pixelPtr = (PIXEL_TYPE *) PIXEL_ADDRESS(x0,y0); 158#endif 159 160 if (dx<0) { 161 dx = -dx; /* make positive */ 162 xstep = -1; 163#ifdef DEPTH_TYPE 164 zPtrXstep = -((GLint)sizeof(DEPTH_TYPE)); 165#endif 166#ifdef PIXEL_ADDRESS 167 pixelXstep = -((GLint)sizeof(PIXEL_TYPE)); 168#endif 169 } 170 else { 171 xstep = 1; 172#ifdef DEPTH_TYPE 173 zPtrXstep = ((GLint)sizeof(DEPTH_TYPE)); 174#endif 175#ifdef PIXEL_ADDRESS 176 pixelXstep = ((GLint)sizeof(PIXEL_TYPE)); 177#endif 178 } 179 180 if (dy<0) { 181 dy = -dy; /* make positive */ 182 ystep = -1; 183#ifdef DEPTH_TYPE 184 zPtrYstep = -((GLint) (ctx->DrawBuffer->Width * sizeof(DEPTH_TYPE))); 185#endif 186#ifdef PIXEL_ADDRESS 187 pixelYstep = BYTES_PER_ROW; 188#endif 189 } 190 else { 191 ystep = 1; 192#ifdef DEPTH_TYPE 193 zPtrYstep = (GLint) (ctx->DrawBuffer->Width * sizeof(DEPTH_TYPE)); 194#endif 195#ifdef PIXEL_ADDRESS 196 pixelYstep = -(BYTES_PER_ROW); 197#endif 198 } 199 200 ASSERT(dx >= 0); 201 ASSERT(dy >= 0); 202 203 numPixels = MAX2(dx, dy); 204 205 /* 206 * Span setup: compute start and step values for all interpolated values. 207 */ 208#ifdef INTERP_RGBA 209 interpFlags |= SPAN_RGBA; 210 if (ctx->Light.ShadeModel == GL_SMOOTH) { 211 span.red = ChanToFixed(vert0->color[0]); 212 span.green = ChanToFixed(vert0->color[1]); 213 span.blue = ChanToFixed(vert0->color[2]); 214 span.alpha = ChanToFixed(vert0->color[3]); 215 span.redStep = (ChanToFixed(vert1->color[0]) - span.red ) / numPixels; 216 span.greenStep = (ChanToFixed(vert1->color[1]) - span.green) / numPixels; 217 span.blueStep = (ChanToFixed(vert1->color[2]) - span.blue ) / numPixels; 218 span.alphaStep = (ChanToFixed(vert1->color[3]) - span.alpha) / numPixels; 219 } 220 else { 221 span.red = ChanToFixed(vert1->color[0]); 222 span.green = ChanToFixed(vert1->color[1]); 223 span.blue = ChanToFixed(vert1->color[2]); 224 span.alpha = ChanToFixed(vert1->color[3]); 225 span.redStep = 0; 226 span.greenStep = 0; 227 span.blueStep = 0; 228 span.alphaStep = 0; 229 } 230#endif 231#ifdef INTERP_SPEC 232 interpFlags |= SPAN_SPEC; 233 if (ctx->Light.ShadeModel == GL_SMOOTH) { 234 span.specRed = ChanToFixed(vert0->specular[0]); 235 span.specGreen = ChanToFixed(vert0->specular[1]); 236 span.specBlue = ChanToFixed(vert0->specular[2]); 237 span.specRedStep = (ChanToFixed(vert1->specular[0]) - span.specRed) / numPixels; 238 span.specGreenStep = (ChanToFixed(vert1->specular[1]) - span.specBlue) / numPixels; 239 span.specBlueStep = (ChanToFixed(vert1->specular[2]) - span.specGreen) / numPixels; 240 } 241 else { 242 span.specRed = ChanToFixed(vert1->specular[0]); 243 span.specGreen = ChanToFixed(vert1->specular[1]); 244 span.specBlue = ChanToFixed(vert1->specular[2]); 245 span.specRedStep = 0; 246 span.specGreenStep = 0; 247 span.specBlueStep = 0; 248 } 249#endif 250#ifdef INTERP_INDEX 251 interpFlags |= SPAN_INDEX; 252 if (ctx->Light.ShadeModel == GL_SMOOTH) { 253 span.index = FloatToFixed(vert0->index); 254 span.indexStep = FloatToFixed(vert1->index - vert0->index) / numPixels; 255 } 256 else { 257 span.index = FloatToFixed(vert1->index); 258 span.indexStep = 0; 259 } 260#endif 261#if defined(INTERP_Z) || defined(DEPTH_TYPE) 262 interpFlags |= SPAN_Z; 263 { 264 if (depthBits <= 16) { 265 span.z = FloatToFixed(vert0->win[2]) + FIXED_HALF; 266 span.zStep = FloatToFixed(vert1->win[2] - vert0->win[2]) / numPixels; 267 } 268 else { 269 /* don't use fixed point */ 270 span.z = (GLint) vert0->win[2]; 271 span.zStep = (GLint) ((vert1->win[2] - vert0->win[2]) / numPixels); 272 } 273 } 274#endif 275#ifdef INTERP_FOG 276 interpFlags |= SPAN_FOG; 277 span.fog = vert0->fog; 278 span.fogStep = (vert1->fog - vert0->fog) / numPixels; 279#endif 280#ifdef INTERP_TEX 281 interpFlags |= SPAN_TEXTURE; 282 { 283 const GLfloat invw0 = vert0->win[3]; 284 const GLfloat invw1 = vert1->win[3]; 285 const GLfloat invLen = 1.0F / numPixels; 286 GLfloat ds, dt, dr, dq; 287 span.tex[0][0] = invw0 * vert0->texcoord[0][0]; 288 span.tex[0][1] = invw0 * vert0->texcoord[0][1]; 289 span.tex[0][2] = invw0 * vert0->texcoord[0][2]; 290 span.tex[0][3] = invw0 * vert0->texcoord[0][3]; 291 ds = (invw1 * vert1->texcoord[0][0]) - span.tex[0][0]; 292 dt = (invw1 * vert1->texcoord[0][1]) - span.tex[0][1]; 293 dr = (invw1 * vert1->texcoord[0][2]) - span.tex[0][2]; 294 dq = (invw1 * vert1->texcoord[0][3]) - span.tex[0][3]; 295 span.texStepX[0][0] = ds * invLen; 296 span.texStepX[0][1] = dt * invLen; 297 span.texStepX[0][2] = dr * invLen; 298 span.texStepX[0][3] = dq * invLen; 299 span.texStepY[0][0] = 0.0F; 300 span.texStepY[0][1] = 0.0F; 301 span.texStepY[0][2] = 0.0F; 302 span.texStepY[0][3] = 0.0F; 303 } 304#endif 305#ifdef INTERP_MULTITEX 306 interpFlags |= SPAN_TEXTURE; 307 { 308 const GLfloat invLen = 1.0F / numPixels; 309 GLuint u; 310 for (u = 0; u < ctx->Const.MaxTextureUnits; u++) { 311 if (ctx->Texture.Unit[u]._ReallyEnabled) { 312 const GLfloat invw0 = vert0->win[3]; 313 const GLfloat invw1 = vert1->win[3]; 314 GLfloat ds, dt, dr, dq; 315 span.tex[u][0] = invw0 * vert0->texcoord[u][0]; 316 span.tex[u][1] = invw0 * vert0->texcoord[u][1]; 317 span.tex[u][2] = invw0 * vert0->texcoord[u][2]; 318 span.tex[u][3] = invw0 * vert0->texcoord[u][3]; 319 ds = (invw1 * vert1->texcoord[u][0]) - span.tex[u][0]; 320 dt = (invw1 * vert1->texcoord[u][1]) - span.tex[u][1]; 321 dr = (invw1 * vert1->texcoord[u][2]) - span.tex[u][2]; 322 dq = (invw1 * vert1->texcoord[u][3]) - span.tex[u][3]; 323 span.texStepX[u][0] = ds * invLen; 324 span.texStepX[u][1] = dt * invLen; 325 span.texStepX[u][2] = dr * invLen; 326 span.texStepX[u][3] = dq * invLen; 327 span.texStepY[u][0] = 0.0F; 328 span.texStepY[u][1] = 0.0F; 329 span.texStepY[u][2] = 0.0F; 330 span.texStepY[u][3] = 0.0F; 331 } 332 } 333 } 334#endif 335 336 INIT_SPAN(span, GL_LINE, numPixels, interpFlags, SPAN_XY); 337 338 /* Need these for fragment prog texcoord interpolation */ 339 span.w = 1.0F; 340 span.dwdx = 0.0F; 341 span.dwdy = 0.0F; 342 343 /* 344 * Draw 345 */ 346 347 if (dx > dy) { 348 /*** X-major line ***/ 349 GLint i; 350 GLint errorInc = dy+dy; 351 GLint error = errorInc-dx; 352 GLint errorDec = error-dx; 353 354 for (i = 0; i < dx; i++) { 355#ifdef DEPTH_TYPE 356 GLdepth Z = FixedToDepth(span.z); 357#endif 358#ifdef PLOT 359 PLOT( x0, y0 ); 360#else 361 span.array->x[i] = x0; 362 span.array->y[i] = y0; 363#endif 364 x0 += xstep; 365#ifdef DEPTH_TYPE 366 zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrXstep); 367 span.z += span.zStep; 368#endif 369#ifdef PIXEL_ADDRESS 370 pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelXstep); 371#endif 372 if (error<0) { 373 error += errorInc; 374 } 375 else { 376 error += errorDec; 377 y0 += ystep; 378#ifdef DEPTH_TYPE 379 zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrYstep); 380#endif 381#ifdef PIXEL_ADDRESS 382 pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelYstep); 383#endif 384 } 385 } 386 } 387 else { 388 /*** Y-major line ***/ 389 GLint i; 390 GLint errorInc = dx+dx; 391 GLint error = errorInc-dy; 392 GLint errorDec = error-dy; 393 394 for (i=0;i<dy;i++) { 395#ifdef DEPTH_TYPE 396 GLdepth Z = FixedToDepth(span.z); 397#endif 398#ifdef PLOT 399 PLOT( x0, y0 ); 400#else 401 span.array->x[i] = x0; 402 span.array->y[i] = y0; 403#endif 404 y0 += ystep; 405#ifdef DEPTH_TYPE 406 zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrYstep); 407 span.z += span.zStep; 408#endif 409#ifdef PIXEL_ADDRESS 410 pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelYstep); 411#endif 412 if (error<0) { 413 error += errorInc; 414 } 415 else { 416 error += errorDec; 417 x0 += xstep; 418#ifdef DEPTH_TYPE 419 zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrXstep); 420#endif 421#ifdef PIXEL_ADDRESS 422 pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelXstep); 423#endif 424 } 425 } 426 } 427 428#ifdef RENDER_SPAN 429 RENDER_SPAN( span ); 430#endif 431 432 (void)span; 433 434} 435 436 437#undef NAME 438#undef INTERP_Z 439#undef INTERP_FOG 440#undef INTERP_RGBA 441#undef INTERP_SPEC 442#undef INTERP_TEX 443#undef INTERP_MULTITEX 444#undef INTERP_INDEX 445#undef PIXEL_ADDRESS 446#undef PIXEL_TYPE 447#undef DEPTH_TYPE 448#undef BYTES_PER_ROW 449#undef SETUP_CODE 450#undef PLOT 451#undef CLIP_HACK 452#undef FixedToDepth 453#undef RENDER_SPAN 454