Details | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 5564 | serge | 1 | /* |
| 2 | * Mesa 3-D graphics library |
||
| 3 | * |
||
| 4 | * Copyright (C) 1999-2007 Brian Paul All Rights Reserved. |
||
| 5 | * |
||
| 6 | * Permission is hereby granted, free of charge, to any person obtaining a |
||
| 7 | * copy of this software and associated documentation files (the "Software"), |
||
| 8 | * to deal in the Software without restriction, including without limitation |
||
| 9 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
||
| 10 | * and/or sell copies of the Software, and to permit persons to whom the |
||
| 11 | * Software is furnished to do so, subject to the following conditions: |
||
| 12 | * |
||
| 13 | * The above copyright notice and this permission notice shall be included |
||
| 14 | * in all copies or substantial portions of the Software. |
||
| 15 | * |
||
| 16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
||
| 17 | * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
||
| 18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
||
| 19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR |
||
| 20 | * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, |
||
| 21 | * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
||
| 22 | * 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_ATTRIBS - if defined, interpolate attribs (texcoords, varying, etc) |
||
| 35 | * |
||
| 36 | * When one can directly address pixels in the color buffer the following |
||
| 37 | * macros can be defined and used to directly compute pixel addresses during |
||
| 38 | * rasterization (see pixelPtr): |
||
| 39 | * PIXEL_TYPE - the datatype of a pixel (GLubyte, GLushort, GLuint) |
||
| 40 | * BYTES_PER_ROW - number of bytes per row in the color buffer |
||
| 41 | * PIXEL_ADDRESS(X,Y) - returns the address of pixel at (X,Y) where |
||
| 42 | * Y==0 at bottom of screen and increases upward. |
||
| 43 | * |
||
| 44 | * Similarly, for direct depth buffer access, this type is used for depth |
||
| 45 | * buffer addressing: |
||
| 46 | * DEPTH_TYPE - either GLushort or GLuint |
||
| 47 | * |
||
| 48 | * Optionally, one may provide one-time setup code |
||
| 49 | * SETUP_CODE - code which is to be executed once per line |
||
| 50 | * |
||
| 51 | * To actually "plot" each pixel the PLOT macro must be defined... |
||
| 52 | * PLOT(X,Y) - code to plot a pixel. Example: |
||
| 53 | * if (Z < *zPtr) { |
||
| 54 | * *zPtr = Z; |
||
| 55 | * color = pack_rgb( FixedToInt(r0), FixedToInt(g0), |
||
| 56 | * FixedToInt(b0) ); |
||
| 57 | * put_pixel( X, Y, color ); |
||
| 58 | * } |
||
| 59 | * |
||
| 60 | * This code was designed for the origin to be in the lower-left corner. |
||
| 61 | * |
||
| 62 | */ |
||
| 63 | |||
| 64 | |||
| 65 | static void |
||
| 66 | NAME( struct gl_context *ctx, const SWvertex *vert0, const SWvertex *vert1 ) |
||
| 67 | { |
||
| 68 | const SWcontext *swrast = SWRAST_CONTEXT(ctx); |
||
| 69 | SWspan span; |
||
| 70 | GLuint interpFlags = 0; |
||
| 71 | GLint x0 = (GLint) vert0->attrib[VARYING_SLOT_POS][0]; |
||
| 72 | GLint x1 = (GLint) vert1->attrib[VARYING_SLOT_POS][0]; |
||
| 73 | GLint y0 = (GLint) vert0->attrib[VARYING_SLOT_POS][1]; |
||
| 74 | GLint y1 = (GLint) vert1->attrib[VARYING_SLOT_POS][1]; |
||
| 75 | GLint dx, dy; |
||
| 76 | GLint numPixels; |
||
| 77 | GLint xstep, ystep; |
||
| 78 | #if defined(DEPTH_TYPE) |
||
| 79 | const GLint depthBits = ctx->DrawBuffer->Visual.depthBits; |
||
| 80 | const GLint fixedToDepthShift = depthBits <= 16 ? FIXED_SHIFT : 0; |
||
| 81 | struct gl_renderbuffer *zrb = ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer; |
||
| 82 | #define FixedToDepth(F) ((F) >> fixedToDepthShift) |
||
| 83 | GLint zPtrXstep, zPtrYstep; |
||
| 84 | DEPTH_TYPE *zPtr; |
||
| 85 | #elif defined(INTERP_Z) |
||
| 86 | const GLint depthBits = ctx->DrawBuffer->Visual.depthBits; |
||
| 87 | #endif |
||
| 88 | #ifdef PIXEL_ADDRESS |
||
| 89 | PIXEL_TYPE *pixelPtr; |
||
| 90 | GLint pixelXstep, pixelYstep; |
||
| 91 | #endif |
||
| 92 | |||
| 93 | #ifdef SETUP_CODE |
||
| 94 | SETUP_CODE |
||
| 95 | #endif |
||
| 96 | |||
| 97 | (void) swrast; |
||
| 98 | |||
| 99 | /* Cull primitives with malformed coordinates. |
||
| 100 | */ |
||
| 101 | { |
||
| 102 | GLfloat tmp = vert0->attrib[VARYING_SLOT_POS][0] + vert0->attrib[VARYING_SLOT_POS][1] |
||
| 103 | + vert1->attrib[VARYING_SLOT_POS][0] + vert1->attrib[VARYING_SLOT_POS][1]; |
||
| 104 | if (IS_INF_OR_NAN(tmp)) |
||
| 105 | return; |
||
| 106 | } |
||
| 107 | |||
| 108 | /* |
||
| 109 | printf("%s():\n", __func__); |
||
| 110 | printf(" (%f, %f, %f) -> (%f, %f, %f)\n", |
||
| 111 | vert0->attrib[VARYING_SLOT_POS][0], |
||
| 112 | vert0->attrib[VARYING_SLOT_POS][1], |
||
| 113 | vert0->attrib[VARYING_SLOT_POS][2], |
||
| 114 | vert1->attrib[VARYING_SLOT_POS][0], |
||
| 115 | vert1->attrib[VARYING_SLOT_POS][1], |
||
| 116 | vert1->attrib[VARYING_SLOT_POS][2]); |
||
| 117 | printf(" (%d, %d, %d) -> (%d, %d, %d)\n", |
||
| 118 | vert0->color[0], vert0->color[1], vert0->color[2], |
||
| 119 | vert1->color[0], vert1->color[1], vert1->color[2]); |
||
| 120 | printf(" (%d, %d, %d) -> (%d, %d, %d)\n", |
||
| 121 | vert0->specular[0], vert0->specular[1], vert0->specular[2], |
||
| 122 | vert1->specular[0], vert1->specular[1], vert1->specular[2]); |
||
| 123 | */ |
||
| 124 | |||
| 125 | /* |
||
| 126 | * Despite being clipped to the view volume, the line's window coordinates |
||
| 127 | * may just lie outside the window bounds. That is, if the legal window |
||
| 128 | * coordinates are [0,W-1][0,H-1], it's possible for x==W and/or y==H. |
||
| 129 | * This quick and dirty code nudges the endpoints inside the window if |
||
| 130 | * necessary. |
||
| 131 | */ |
||
| 132 | #ifdef CLIP_HACK |
||
| 133 | { |
||
| 134 | GLint w = ctx->DrawBuffer->Width; |
||
| 135 | GLint h = ctx->DrawBuffer->Height; |
||
| 136 | if ((x0==w) | (x1==w)) { |
||
| 137 | if ((x0==w) & (x1==w)) |
||
| 138 | return; |
||
| 139 | x0 -= x0==w; |
||
| 140 | x1 -= x1==w; |
||
| 141 | } |
||
| 142 | if ((y0==h) | (y1==h)) { |
||
| 143 | if ((y0==h) & (y1==h)) |
||
| 144 | return; |
||
| 145 | y0 -= y0==h; |
||
| 146 | y1 -= y1==h; |
||
| 147 | } |
||
| 148 | } |
||
| 149 | #endif |
||
| 150 | |||
| 151 | dx = x1 - x0; |
||
| 152 | dy = y1 - y0; |
||
| 153 | if (dx == 0 && dy == 0) |
||
| 154 | return; |
||
| 155 | |||
| 156 | /* |
||
| 157 | printf("%s %d,%d %g %g %g %g %g %g %g %g\n", __func__, dx, dy, |
||
| 158 | vert0->attrib[VARYING_SLOT_COL1][0], |
||
| 159 | vert0->attrib[VARYING_SLOT_COL1][1], |
||
| 160 | vert0->attrib[VARYING_SLOT_COL1][2], |
||
| 161 | vert0->attrib[VARYING_SLOT_COL1][3], |
||
| 162 | vert1->attrib[VARYING_SLOT_COL1][0], |
||
| 163 | vert1->attrib[VARYING_SLOT_COL1][1], |
||
| 164 | vert1->attrib[VARYING_SLOT_COL1][2], |
||
| 165 | vert1->attrib[VARYING_SLOT_COL1][3]); |
||
| 166 | */ |
||
| 167 | |||
| 168 | #ifdef DEPTH_TYPE |
||
| 169 | zPtr = (DEPTH_TYPE *) _swrast_pixel_address(zrb, x0, y0); |
||
| 170 | #endif |
||
| 171 | #ifdef PIXEL_ADDRESS |
||
| 172 | pixelPtr = (PIXEL_TYPE *) PIXEL_ADDRESS(x0,y0); |
||
| 173 | #endif |
||
| 174 | |||
| 175 | if (dx<0) { |
||
| 176 | dx = -dx; /* make positive */ |
||
| 177 | xstep = -1; |
||
| 178 | #ifdef DEPTH_TYPE |
||
| 179 | zPtrXstep = -((GLint)sizeof(DEPTH_TYPE)); |
||
| 180 | #endif |
||
| 181 | #ifdef PIXEL_ADDRESS |
||
| 182 | pixelXstep = -((GLint)sizeof(PIXEL_TYPE)); |
||
| 183 | #endif |
||
| 184 | } |
||
| 185 | else { |
||
| 186 | xstep = 1; |
||
| 187 | #ifdef DEPTH_TYPE |
||
| 188 | zPtrXstep = ((GLint)sizeof(DEPTH_TYPE)); |
||
| 189 | #endif |
||
| 190 | #ifdef PIXEL_ADDRESS |
||
| 191 | pixelXstep = ((GLint)sizeof(PIXEL_TYPE)); |
||
| 192 | #endif |
||
| 193 | } |
||
| 194 | |||
| 195 | if (dy<0) { |
||
| 196 | dy = -dy; /* make positive */ |
||
| 197 | ystep = -1; |
||
| 198 | #ifdef DEPTH_TYPE |
||
| 199 | zPtrYstep = -((GLint) (ctx->DrawBuffer->Width * sizeof(DEPTH_TYPE))); |
||
| 200 | #endif |
||
| 201 | #ifdef PIXEL_ADDRESS |
||
| 202 | pixelYstep = BYTES_PER_ROW; |
||
| 203 | #endif |
||
| 204 | } |
||
| 205 | else { |
||
| 206 | ystep = 1; |
||
| 207 | #ifdef DEPTH_TYPE |
||
| 208 | zPtrYstep = (GLint) (ctx->DrawBuffer->Width * sizeof(DEPTH_TYPE)); |
||
| 209 | #endif |
||
| 210 | #ifdef PIXEL_ADDRESS |
||
| 211 | pixelYstep = -(BYTES_PER_ROW); |
||
| 212 | #endif |
||
| 213 | } |
||
| 214 | |||
| 215 | assert(dx >= 0); |
||
| 216 | assert(dy >= 0); |
||
| 217 | |||
| 218 | numPixels = MAX2(dx, dy); |
||
| 219 | |||
| 220 | /* |
||
| 221 | * Span setup: compute start and step values for all interpolated values. |
||
| 222 | */ |
||
| 223 | interpFlags |= SPAN_RGBA; |
||
| 224 | if (ctx->Light.ShadeModel == GL_SMOOTH) { |
||
| 225 | span.red = ChanToFixed(vert0->color[0]); |
||
| 226 | span.green = ChanToFixed(vert0->color[1]); |
||
| 227 | span.blue = ChanToFixed(vert0->color[2]); |
||
| 228 | span.alpha = ChanToFixed(vert0->color[3]); |
||
| 229 | span.redStep = (ChanToFixed(vert1->color[0]) - span.red ) / numPixels; |
||
| 230 | span.greenStep = (ChanToFixed(vert1->color[1]) - span.green) / numPixels; |
||
| 231 | span.blueStep = (ChanToFixed(vert1->color[2]) - span.blue ) / numPixels; |
||
| 232 | span.alphaStep = (ChanToFixed(vert1->color[3]) - span.alpha) / numPixels; |
||
| 233 | } |
||
| 234 | else { |
||
| 235 | span.red = ChanToFixed(vert1->color[0]); |
||
| 236 | span.green = ChanToFixed(vert1->color[1]); |
||
| 237 | span.blue = ChanToFixed(vert1->color[2]); |
||
| 238 | span.alpha = ChanToFixed(vert1->color[3]); |
||
| 239 | span.redStep = 0; |
||
| 240 | span.greenStep = 0; |
||
| 241 | span.blueStep = 0; |
||
| 242 | span.alphaStep = 0; |
||
| 243 | } |
||
| 244 | #if defined(INTERP_Z) || defined(DEPTH_TYPE) |
||
| 245 | interpFlags |= SPAN_Z; |
||
| 246 | { |
||
| 247 | if (depthBits <= 16) { |
||
| 248 | span.z = FloatToFixed(vert0->attrib[VARYING_SLOT_POS][2]) + FIXED_HALF; |
||
| 249 | span.zStep = FloatToFixed( vert1->attrib[VARYING_SLOT_POS][2] |
||
| 250 | - vert0->attrib[VARYING_SLOT_POS][2]) / numPixels; |
||
| 251 | } |
||
| 252 | else { |
||
| 253 | /* don't use fixed point */ |
||
| 254 | span.z = (GLuint) vert0->attrib[VARYING_SLOT_POS][2]; |
||
| 255 | span.zStep = (GLint) (( vert1->attrib[VARYING_SLOT_POS][2] |
||
| 256 | - vert0->attrib[VARYING_SLOT_POS][2]) / numPixels); |
||
| 257 | } |
||
| 258 | } |
||
| 259 | #endif |
||
| 260 | #if defined(INTERP_ATTRIBS) |
||
| 261 | { |
||
| 262 | const GLfloat invLen = 1.0F / numPixels; |
||
| 263 | const GLfloat invw0 = vert0->attrib[VARYING_SLOT_POS][3]; |
||
| 264 | const GLfloat invw1 = vert1->attrib[VARYING_SLOT_POS][3]; |
||
| 265 | |||
| 266 | span.attrStart[VARYING_SLOT_POS][3] = invw0; |
||
| 267 | span.attrStepX[VARYING_SLOT_POS][3] = (invw1 - invw0) * invLen; |
||
| 268 | span.attrStepY[VARYING_SLOT_POS][3] = 0.0; |
||
| 269 | |||
| 270 | ATTRIB_LOOP_BEGIN |
||
| 271 | if (swrast->_InterpMode[attr] == GL_FLAT) { |
||
| 272 | COPY_4V(span.attrStart[attr], vert1->attrib[attr]); |
||
| 273 | ASSIGN_4V(span.attrStepX[attr], 0.0, 0.0, 0.0, 0.0); |
||
| 274 | } |
||
| 275 | else { |
||
| 276 | GLuint c; |
||
| 277 | for (c = 0; c < 4; c++) { |
||
| 278 | float da; |
||
| 279 | span.attrStart[attr][c] = invw0 * vert0->attrib[attr][c]; |
||
| 280 | da = (invw1 * vert1->attrib[attr][c]) - span.attrStart[attr][c]; |
||
| 281 | span.attrStepX[attr][c] = da * invLen; |
||
| 282 | } |
||
| 283 | } |
||
| 284 | ASSIGN_4V(span.attrStepY[attr], 0.0, 0.0, 0.0, 0.0); |
||
| 285 | ATTRIB_LOOP_END |
||
| 286 | } |
||
| 287 | #endif |
||
| 288 | |||
| 289 | INIT_SPAN(span, GL_LINE); |
||
| 290 | span.end = numPixels; |
||
| 291 | span.interpMask = interpFlags; |
||
| 292 | span.arrayMask = SPAN_XY; |
||
| 293 | |||
| 294 | span.facing = swrast->PointLineFacing; |
||
| 295 | |||
| 296 | |||
| 297 | /* |
||
| 298 | * Draw |
||
| 299 | */ |
||
| 300 | |||
| 301 | if (dx > dy) { |
||
| 302 | /*** X-major line ***/ |
||
| 303 | GLint i; |
||
| 304 | GLint errorInc = dy+dy; |
||
| 305 | GLint error = errorInc-dx; |
||
| 306 | GLint errorDec = error-dx; |
||
| 307 | |||
| 308 | for (i = 0; i < dx; i++) { |
||
| 309 | #ifdef DEPTH_TYPE |
||
| 310 | GLuint Z = FixedToDepth(span.z); |
||
| 311 | #endif |
||
| 312 | #ifdef PLOT |
||
| 313 | PLOT( x0, y0 ); |
||
| 314 | #else |
||
| 315 | span.array->x[i] = x0; |
||
| 316 | span.array->y[i] = y0; |
||
| 317 | #endif |
||
| 318 | x0 += xstep; |
||
| 319 | #ifdef DEPTH_TYPE |
||
| 320 | zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrXstep); |
||
| 321 | span.z += span.zStep; |
||
| 322 | #endif |
||
| 323 | #ifdef PIXEL_ADDRESS |
||
| 324 | pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelXstep); |
||
| 325 | #endif |
||
| 326 | if (error < 0) { |
||
| 327 | error += errorInc; |
||
| 328 | } |
||
| 329 | else { |
||
| 330 | error += errorDec; |
||
| 331 | y0 += ystep; |
||
| 332 | #ifdef DEPTH_TYPE |
||
| 333 | zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrYstep); |
||
| 334 | #endif |
||
| 335 | #ifdef PIXEL_ADDRESS |
||
| 336 | pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelYstep); |
||
| 337 | #endif |
||
| 338 | } |
||
| 339 | } |
||
| 340 | } |
||
| 341 | else { |
||
| 342 | /*** Y-major line ***/ |
||
| 343 | GLint i; |
||
| 344 | GLint errorInc = dx+dx; |
||
| 345 | GLint error = errorInc-dy; |
||
| 346 | GLint errorDec = error-dy; |
||
| 347 | |||
| 348 | for (i=0;i |
||
| 349 | #ifdef DEPTH_TYPE |
||
| 350 | GLuint Z = FixedToDepth(span.z); |
||
| 351 | #endif |
||
| 352 | #ifdef PLOT |
||
| 353 | PLOT( x0, y0 ); |
||
| 354 | #else |
||
| 355 | span.array->x[i] = x0; |
||
| 356 | span.array->y[i] = y0; |
||
| 357 | #endif |
||
| 358 | y0 += ystep; |
||
| 359 | #ifdef DEPTH_TYPE |
||
| 360 | zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrYstep); |
||
| 361 | span.z += span.zStep; |
||
| 362 | #endif |
||
| 363 | #ifdef PIXEL_ADDRESS |
||
| 364 | pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelYstep); |
||
| 365 | #endif |
||
| 366 | if (error<0) { |
||
| 367 | error += errorInc; |
||
| 368 | } |
||
| 369 | else { |
||
| 370 | error += errorDec; |
||
| 371 | x0 += xstep; |
||
| 372 | #ifdef DEPTH_TYPE |
||
| 373 | zPtr = (DEPTH_TYPE *) ((GLubyte*) zPtr + zPtrXstep); |
||
| 374 | #endif |
||
| 375 | #ifdef PIXEL_ADDRESS |
||
| 376 | pixelPtr = (PIXEL_TYPE*) ((GLubyte*) pixelPtr + pixelXstep); |
||
| 377 | #endif |
||
| 378 | } |
||
| 379 | } |
||
| 380 | } |
||
| 381 | |||
| 382 | #ifdef RENDER_SPAN |
||
| 383 | RENDER_SPAN( span ); |
||
| 384 | #endif |
||
| 385 | |||
| 386 | (void)span; |
||
| 387 | |||
| 388 | } |
||
| 389 | |||
| 390 | |||
| 391 | #undef NAME |
||
| 392 | #undef INTERP_Z |
||
| 393 | #undef INTERP_ATTRIBS |
||
| 394 | #undef PIXEL_ADDRESS |
||
| 395 | #undef PIXEL_TYPE |
||
| 396 | #undef DEPTH_TYPE |
||
| 397 | #undef BYTES_PER_ROW |
||
| 398 | #undef SETUP_CODE |
||
| 399 | #undef PLOT |
||
| 400 | #undef CLIP_HACK |
||
| 401 | #undef FixedToDepth |
||
| 402 | #undef RENDER_SPAN |