1 /* 2 * Mesa 3-D graphics library 3 * 4 * Copyright (C) 1999-2006 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 #include "c99_math.h" 27 #include "main/glheader.h" 28 #include "main/light.h" 29 #include "main/macros.h" 30 #include "main/imports.h" 31 #include "util/simple_list.h" 32 #include "main/mtypes.h" 33 34 #include "math/m_translate.h" 35 36 #include "util/bitscan.h" 37 38 #include "t_context.h" 39 #include "t_pipeline.h" 40 #include "tnl.h" 41 42 #define LIGHT_TWOSIDE 0x1 43 #define LIGHT_MATERIAL 0x2 44 #define MAX_LIGHT_FUNC 0x4 45 46 typedef void (*light_func)( struct gl_context *ctx, 47 struct vertex_buffer *VB, 48 struct tnl_pipeline_stage *stage, 49 GLvector4f *input ); 50 51 /** 52 * Information for updating current material attributes from vertex color, 53 * for GL_COLOR_MATERIAL. 54 */ 55 struct material_cursor { 56 const GLfloat *ptr; /* points to src vertex color (in VB array) */ 57 GLuint stride; /* stride to next vertex color (bytes) */ 58 GLfloat *current; /* points to material attribute to update */ 59 GLuint size; /* vertex/color size: 1, 2, 3 or 4 */ 60 }; 61 62 /** 63 * Data private to this pipeline stage. 64 */ 65 struct light_stage_data { 66 GLvector4f Input; 67 GLvector4f LitColor[2]; 68 GLvector4f LitSecondary[2]; 69 light_func *light_func_tab; 70 71 struct material_cursor mat[MAT_ATTRIB_MAX]; 72 GLuint mat_count; 73 GLuint mat_bitmask; 74 }; 75 76 77 #define LIGHT_STAGE_DATA(stage) ((struct light_stage_data *)(stage->privatePtr)) 78 79 80 81 /**********************************************************************/ 82 /***** Lighting computation *****/ 83 /**********************************************************************/ 84 85 86 /* 87 * Notes: 88 * When two-sided lighting is enabled we compute the color (or index) 89 * for both the front and back side of the primitive. Then, when the 90 * orientation of the facet is later learned, we can determine which 91 * color (or index) to use for rendering. 92 * 93 * KW: We now know orientation in advance and only shade for 94 * the side or sides which are actually required. 95 * 96 * Variables: 97 * n = normal vector 98 * V = vertex position 99 * P = light source position 100 * Pe = (0,0,0,1) 101 * 102 * Precomputed: 103 * IF P[3]==0 THEN 104 * // light at infinity 105 * IF local_viewer THEN 106 * _VP_inf_norm = unit vector from V to P // Precompute 107 * ELSE 108 * // eye at infinity 109 * _h_inf_norm = Normalize( VP + <0,0,1> ) // Precompute 110 * ENDIF 111 * ENDIF 112 * 113 * Functions: 114 * Normalize( v ) = normalized vector v 115 * Magnitude( v ) = length of vector v 116 */ 117 118 119 120 static void 121 validate_shine_table( struct gl_context *ctx, GLuint side, GLfloat shininess ) 122 { 123 TNLcontext *tnl = TNL_CONTEXT(ctx); 124 struct tnl_shine_tab *list = tnl->_ShineTabList; 125 struct tnl_shine_tab *s; 126 127 assert(side < 2); 128 129 foreach(s, list) 130 if ( s->shininess == shininess ) 131 break; 132 133 if (s == list) { 134 GLint j; 135 GLfloat *m; 136 137 foreach(s, list) 138 if (s->refcount == 0) 139 break; 140 141 m = s->tab; 142 m[0] = 0.0F; 143 if (shininess == 0.0F) { 144 for (j = 1 ; j <= SHINE_TABLE_SIZE ; j++) 145 m[j] = 1.0F; 146 } 147 else { 148 for (j = 1 ; j < SHINE_TABLE_SIZE ; j++) { 149 GLfloat t, x = j / (GLfloat) (SHINE_TABLE_SIZE - 1); 150 if (x < 0.005F) /* underflow check */ 151 x = 0.005F; 152 t = powf(x, shininess); 153 if (t > 1e-20F) 154 m[j] = t; 155 else 156 m[j] = 0.0F; 157 } 158 m[SHINE_TABLE_SIZE] = 1.0F; 159 } 160 161 s->shininess = shininess; 162 } 163 164 if (tnl->_ShineTable[side]) 165 tnl->_ShineTable[side]->refcount--; 166 167 tnl->_ShineTable[side] = s; 168 move_to_tail( list, s ); 169 s->refcount++; 170 } 171 172 173 void 174 _tnl_validate_shine_tables( struct gl_context *ctx ) 175 { 176 TNLcontext *tnl = TNL_CONTEXT(ctx); 177 GLfloat shininess; 178 179 shininess = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_SHININESS][0]; 180 if (!tnl->_ShineTable[0] || tnl->_ShineTable[0]->shininess != shininess) 181 validate_shine_table( ctx, 0, shininess ); 182 183 shininess = ctx->Light.Material.Attrib[MAT_ATTRIB_BACK_SHININESS][0]; 184 if (!tnl->_ShineTable[1] || tnl->_ShineTable[1]->shininess != shininess) 185 validate_shine_table( ctx, 1, shininess ); 186 } 187 188 189 /** 190 * In the case of colormaterial, the effected material attributes 191 * should already have been bound to point to the incoming color data, 192 * prior to running the pipeline. 193 * This function copies the vertex's color to the material attributes 194 * which are tracking glColor. 195 * It's called per-vertex in the lighting loop. 196 */ 197 static void 198 update_materials(struct gl_context *ctx, struct light_stage_data *store) 199 { 200 GLuint i; 201 202 for (i = 0 ; i < store->mat_count ; i++) { 203 /* update the material */ 204 COPY_CLEAN_4V(store->mat[i].current, store->mat[i].size, store->mat[i].ptr); 205 /* increment src vertex color pointer */ 206 STRIDE_F(store->mat[i].ptr, store->mat[i].stride); 207 } 208 209 /* recompute derived light/material values */ 210 _mesa_update_material( ctx, store->mat_bitmask ); 211 /* XXX we should only call this if we're tracking/changing the specular 212 * exponent. 213 */ 214 _tnl_validate_shine_tables( ctx ); 215 } 216 217 218 /** 219 * Prepare things prior to running the lighting stage. 220 * Return number of material attributes which will track vertex color. 221 */ 222 static GLuint 223 prepare_materials(struct gl_context *ctx, 224 struct vertex_buffer *VB, struct light_stage_data *store) 225 { 226 GLuint i; 227 228 store->mat_count = 0; 229 store->mat_bitmask = 0; 230 231 /* Examine the _ColorMaterialBitmask to determine which materials 232 * track vertex color. Override the material attribute's pointer 233 * with the color pointer for each one. 234 */ 235 if (ctx->Light.ColorMaterialEnabled) { 236 GLbitfield bitmask = ctx->Light._ColorMaterialBitmask; 237 while (bitmask) { 238 const int i = u_bit_scan(&bitmask); 239 VB->AttribPtr[_TNL_ATTRIB_MAT_FRONT_AMBIENT + i] = 240 VB->AttribPtr[_TNL_ATTRIB_COLOR0]; 241 } 242 } 243 244 /* Now, for each material attribute that's tracking vertex color, save 245 * some values (ptr, stride, size, current) that we'll need in 246 * update_materials(), above, that'll actually copy the vertex color to 247 * the material attribute(s). 248 */ 249 for (i = _TNL_FIRST_MAT; i <= _TNL_LAST_MAT; i++) { 250 if (VB->AttribPtr[i]->stride) { 251 const GLuint j = store->mat_count++; 252 const GLuint attr = i - _TNL_ATTRIB_MAT_FRONT_AMBIENT; 253 store->mat[j].ptr = VB->AttribPtr[i]->start; 254 store->mat[j].stride = VB->AttribPtr[i]->stride; 255 store->mat[j].size = VB->AttribPtr[i]->size; 256 store->mat[j].current = ctx->Light.Material.Attrib[attr]; 257 store->mat_bitmask |= (1<<attr); 258 } 259 } 260 261 /* FIXME: Is this already done? 262 */ 263 _mesa_update_material( ctx, ~0 ); 264 265 _tnl_validate_shine_tables( ctx ); 266 267 return store->mat_count; 268 } 269 270 /* 271 * Compute dp ^ SpecularExponent. 272 * Lerp between adjacent values in the f(x) lookup table, giving a 273 * continuous function, with adequate overall accuracy. (Though still 274 * pretty good compared to a straight lookup). 275 */ 276 static inline GLfloat 277 lookup_shininess(const struct gl_context *ctx, GLuint face, GLfloat dp) 278 { 279 TNLcontext *tnl = TNL_CONTEXT(ctx); 280 const struct tnl_shine_tab *tab = tnl->_ShineTable[face]; 281 float f = dp * (SHINE_TABLE_SIZE - 1); 282 int k = (int) f; 283 if (k < 0 /* gcc may cast an overflow float value to negative int value */ 284 || k > SHINE_TABLE_SIZE - 2) 285 return powf(dp, tab->shininess); 286 else 287 return tab->tab[k] + (f - k) * (tab->tab[k+1] - tab->tab[k]); 288 } 289 290 /* Tables for all the shading functions. 291 */ 292 static light_func _tnl_light_tab[MAX_LIGHT_FUNC]; 293 static light_func _tnl_light_fast_tab[MAX_LIGHT_FUNC]; 294 static light_func _tnl_light_fast_single_tab[MAX_LIGHT_FUNC]; 295 static light_func _tnl_light_spec_tab[MAX_LIGHT_FUNC]; 296 297 #define TAG(x) x 298 #define IDX (0) 299 #include "t_vb_lighttmp.h" 300 301 #define TAG(x) x##_twoside 302 #define IDX (LIGHT_TWOSIDE) 303 #include "t_vb_lighttmp.h" 304 305 #define TAG(x) x##_material 306 #define IDX (LIGHT_MATERIAL) 307 #include "t_vb_lighttmp.h" 308 309 #define TAG(x) x##_twoside_material 310 #define IDX (LIGHT_TWOSIDE|LIGHT_MATERIAL) 311 #include "t_vb_lighttmp.h" 312 313 314 static void init_lighting_tables( void ) 315 { 316 static int done; 317 318 if (!done) { 319 init_light_tab(); 320 init_light_tab_twoside(); 321 init_light_tab_material(); 322 init_light_tab_twoside_material(); 323 done = 1; 324 } 325 } 326 327 328 static GLboolean run_lighting( struct gl_context *ctx, 329 struct tnl_pipeline_stage *stage ) 330 { 331 struct light_stage_data *store = LIGHT_STAGE_DATA(stage); 332 TNLcontext *tnl = TNL_CONTEXT(ctx); 333 struct vertex_buffer *VB = &tnl->vb; 334 GLvector4f *input = ctx->_NeedEyeCoords ? VB->EyePtr : VB->AttribPtr[_TNL_ATTRIB_POS]; 335 GLuint idx; 336 337 if (!ctx->Light.Enabled || ctx->VertexProgram._Current) 338 return GL_TRUE; 339 340 /* Make sure we can talk about position x,y and z: 341 */ 342 if (input->size <= 2 && input == VB->AttribPtr[_TNL_ATTRIB_POS]) { 343 344 _math_trans_4f( store->Input.data, 345 VB->AttribPtr[_TNL_ATTRIB_POS]->data, 346 VB->AttribPtr[_TNL_ATTRIB_POS]->stride, 347 GL_FLOAT, 348 VB->AttribPtr[_TNL_ATTRIB_POS]->size, 349 0, 350 VB->Count ); 351 352 if (input->size <= 2) { 353 /* Clean z. 354 */ 355 _mesa_vector4f_clean_elem(&store->Input, VB->Count, 2); 356 } 357 358 if (input->size <= 1) { 359 /* Clean y. 360 */ 361 _mesa_vector4f_clean_elem(&store->Input, VB->Count, 1); 362 } 363 364 input = &store->Input; 365 } 366 367 idx = 0; 368 369 if (prepare_materials( ctx, VB, store )) 370 idx |= LIGHT_MATERIAL; 371 372 if (ctx->Light.Model.TwoSide) 373 idx |= LIGHT_TWOSIDE; 374 375 /* The individual functions know about replaying side-effects 376 * vs. full re-execution. 377 */ 378 store->light_func_tab[idx]( ctx, VB, stage, input ); 379 380 return GL_TRUE; 381 } 382 383 384 /* Called in place of do_lighting when the light table may have changed. 385 */ 386 static void validate_lighting( struct gl_context *ctx, 387 struct tnl_pipeline_stage *stage ) 388 { 389 light_func *tab; 390 391 if (!ctx->Light.Enabled || ctx->VertexProgram._Current) 392 return; 393 394 if (ctx->Light._NeedVertices) { 395 if (ctx->Light.Model.ColorControl == GL_SEPARATE_SPECULAR_COLOR) 396 tab = _tnl_light_spec_tab; 397 else 398 tab = _tnl_light_tab; 399 } 400 else { 401 /* Power of two means only a single active light. */ 402 if (_mesa_is_pow_two(ctx->Light._EnabledLights)) 403 tab = _tnl_light_fast_single_tab; 404 else 405 tab = _tnl_light_fast_tab; 406 } 407 408 409 LIGHT_STAGE_DATA(stage)->light_func_tab = tab; 410 411 /* This and the above should only be done on _NEW_LIGHT: 412 */ 413 TNL_CONTEXT(ctx)->Driver.NotifyMaterialChange( ctx ); 414 } 415 416 417 418 /* Called the first time stage->run is called. In effect, don't 419 * allocate data until the first time the stage is run. 420 */ 421 static GLboolean init_lighting( struct gl_context *ctx, 422 struct tnl_pipeline_stage *stage ) 423 { 424 TNLcontext *tnl = TNL_CONTEXT(ctx); 425 struct light_stage_data *store; 426 GLuint size = tnl->vb.Size; 427 428 stage->privatePtr = malloc(sizeof(*store)); 429 store = LIGHT_STAGE_DATA(stage); 430 if (!store) 431 return GL_FALSE; 432 433 /* Do onetime init. 434 */ 435 init_lighting_tables(); 436 437 _mesa_vector4f_alloc( &store->Input, 0, size, 32 ); 438 _mesa_vector4f_alloc( &store->LitColor[0], 0, size, 32 ); 439 _mesa_vector4f_alloc( &store->LitColor[1], 0, size, 32 ); 440 _mesa_vector4f_alloc( &store->LitSecondary[0], 0, size, 32 ); 441 _mesa_vector4f_alloc( &store->LitSecondary[1], 0, size, 32 ); 442 443 store->LitColor[0].size = 4; 444 store->LitColor[1].size = 4; 445 store->LitSecondary[0].size = 3; 446 store->LitSecondary[1].size = 3; 447 448 return GL_TRUE; 449 } 450 451 452 453 454 static void dtr( struct tnl_pipeline_stage *stage ) 455 { 456 struct light_stage_data *store = LIGHT_STAGE_DATA(stage); 457 458 if (store) { 459 _mesa_vector4f_free( &store->Input ); 460 _mesa_vector4f_free( &store->LitColor[0] ); 461 _mesa_vector4f_free( &store->LitColor[1] ); 462 _mesa_vector4f_free( &store->LitSecondary[0] ); 463 _mesa_vector4f_free( &store->LitSecondary[1] ); 464 free( store ); 465 stage->privatePtr = NULL; 466 } 467 } 468 469 const struct tnl_pipeline_stage _tnl_lighting_stage = 470 { 471 "lighting", /* name */ 472 NULL, /* private_data */ 473 init_lighting, 474 dtr, /* destroy */ 475 validate_lighting, 476 run_lighting 477 }; 478
