1 /*
2 * Mesa 3-D graphics library
3 * Version: 7.1
4 *
5 * Copyright (C) 1999-2007 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 #include "main/glheader.h"
27 #include "main/colormac.h"
28 #include "main/feedback.h"
29 #include "main/light.h"
30 #include "main/macros.h"
31 #include "main/simple_list.h"
32 #include "main/mtypes.h"
33
34 #include "math/m_matrix.h"
35 #include "tnl/tnl.h"
36
37
38
39 /**
40 * Clip a point against the view volume.
41 *
42 * \param v vertex vector describing the point to clip.
43 *
44 * \return zero if outside view volume, or one if inside.
45 */
46 static GLuint
viewclip_point_xy(const GLfloat v[])47 viewclip_point_xy( const GLfloat v[] )
48 {
49 if ( v[0] > v[3] || v[0] < -v[3]
50 || v[1] > v[3] || v[1] < -v[3] ) {
51 return 0;
52 }
53 else {
54 return 1;
55 }
56 }
57
58
59 /**
60 * Clip a point against the far/near Z clipping planes.
61 *
62 * \param v vertex vector describing the point to clip.
63 *
64 * \return zero if outside view volume, or one if inside.
65 */
66 static GLuint
viewclip_point_z(const GLfloat v[])67 viewclip_point_z( const GLfloat v[] )
68 {
69 if (v[2] > v[3] || v[2] < -v[3] ) {
70 return 0;
71 }
72 else {
73 return 1;
74 }
75 }
76
77
78 /**
79 * Clip a point against the user clipping planes.
80 *
81 * \param ctx GL context.
82 * \param v vertex vector describing the point to clip.
83 *
84 * \return zero if the point was clipped, or one otherwise.
85 */
86 static GLuint
userclip_point(struct gl_context * ctx,const GLfloat v[])87 userclip_point( struct gl_context *ctx, const GLfloat v[] )
88 {
89 GLuint p;
90
91 for (p = 0; p < ctx->Const.MaxClipPlanes; p++) {
92 if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {
93 GLfloat dot = v[0] * ctx->Transform._ClipUserPlane[p][0]
94 + v[1] * ctx->Transform._ClipUserPlane[p][1]
95 + v[2] * ctx->Transform._ClipUserPlane[p][2]
96 + v[3] * ctx->Transform._ClipUserPlane[p][3];
97 if (dot < 0.0F) {
98 return 0;
99 }
100 }
101 }
102
103 return 1;
104 }
105
106
107 /**
108 * Compute lighting for the raster position. RGB modes computed.
109 * \param ctx the context
110 * \param vertex vertex location
111 * \param normal normal vector
112 * \param Rcolor returned color
113 * \param Rspec returned specular color (if separate specular enabled)
114 */
115 static void
shade_rastpos(struct gl_context * ctx,const GLfloat vertex[4],const GLfloat normal[3],GLfloat Rcolor[4],GLfloat Rspec[4])116 shade_rastpos(struct gl_context *ctx,
117 const GLfloat vertex[4],
118 const GLfloat normal[3],
119 GLfloat Rcolor[4],
120 GLfloat Rspec[4])
121 {
122 /*const*/ GLfloat (*base)[3] = ctx->Light._BaseColor;
123 const struct gl_light *light;
124 GLfloat diffuseColor[4], specularColor[4]; /* for RGB mode only */
125
126 COPY_3V(diffuseColor, base[0]);
127 diffuseColor[3] = CLAMP(
128 ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_DIFFUSE][3], 0.0F, 1.0F );
129 ASSIGN_4V(specularColor, 0.0, 0.0, 0.0, 1.0);
130
131 foreach (light, &ctx->Light.EnabledList) {
132 GLfloat attenuation = 1.0;
133 GLfloat VP[3]; /* vector from vertex to light pos */
134 GLfloat n_dot_VP;
135 GLfloat diffuseContrib[3], specularContrib[3];
136
137 if (!(light->_Flags & LIGHT_POSITIONAL)) {
138 /* light at infinity */
139 COPY_3V(VP, light->_VP_inf_norm);
140 attenuation = light->_VP_inf_spot_attenuation;
141 }
142 else {
143 /* local/positional light */
144 GLfloat d;
145
146 /* VP = vector from vertex pos to light[i].pos */
147 SUB_3V(VP, light->_Position, vertex);
148 /* d = length(VP) */
149 d = (GLfloat) LEN_3FV( VP );
150 if (d > 1.0e-6) {
151 /* normalize VP */
152 GLfloat invd = 1.0F / d;
153 SELF_SCALE_SCALAR_3V(VP, invd);
154 }
155
156 /* atti */
157 attenuation = 1.0F / (light->ConstantAttenuation + d *
158 (light->LinearAttenuation + d *
159 light->QuadraticAttenuation));
160
161 if (light->_Flags & LIGHT_SPOT) {
162 GLfloat PV_dot_dir = - DOT3(VP, light->_NormSpotDirection);
163
164 if (PV_dot_dir<light->_CosCutoff) {
165 continue;
166 }
167 else {
168 GLfloat spot = powf(PV_dot_dir, light->SpotExponent);
169 attenuation *= spot;
170 }
171 }
172 }
173
174 if (attenuation < 1e-3)
175 continue;
176
177 n_dot_VP = DOT3( normal, VP );
178
179 if (n_dot_VP < 0.0F) {
180 ACC_SCALE_SCALAR_3V(diffuseColor, attenuation, light->_MatAmbient[0]);
181 continue;
182 }
183
184 /* Ambient + diffuse */
185 COPY_3V(diffuseContrib, light->_MatAmbient[0]);
186 ACC_SCALE_SCALAR_3V(diffuseContrib, n_dot_VP, light->_MatDiffuse[0]);
187
188 /* Specular */
189 {
190 const GLfloat *h;
191 GLfloat n_dot_h;
192
193 ASSIGN_3V(specularContrib, 0.0, 0.0, 0.0);
194
195 if (ctx->Light.Model.LocalViewer) {
196 GLfloat v[3];
197 COPY_3V(v, vertex);
198 NORMALIZE_3FV(v);
199 SUB_3V(VP, VP, v);
200 NORMALIZE_3FV(VP);
201 h = VP;
202 }
203 else if (light->_Flags & LIGHT_POSITIONAL) {
204 ACC_3V(VP, ctx->_EyeZDir);
205 NORMALIZE_3FV(VP);
206 h = VP;
207 }
208 else {
209 h = light->_h_inf_norm;
210 }
211
212 n_dot_h = DOT3(normal, h);
213
214 if (n_dot_h > 0.0F) {
215 GLfloat shine;
216 GLfloat spec_coef;
217
218 shine = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_SHININESS][0];
219 spec_coef = powf(n_dot_h, shine);
220
221 if (spec_coef > 1.0e-10) {
222 if (ctx->Light.Model.ColorControl==GL_SEPARATE_SPECULAR_COLOR) {
223 ACC_SCALE_SCALAR_3V( specularContrib, spec_coef,
224 light->_MatSpecular[0]);
225 }
226 else {
227 ACC_SCALE_SCALAR_3V( diffuseContrib, spec_coef,
228 light->_MatSpecular[0]);
229 }
230 }
231 }
232 }
233
234 ACC_SCALE_SCALAR_3V( diffuseColor, attenuation, diffuseContrib );
235 ACC_SCALE_SCALAR_3V( specularColor, attenuation, specularContrib );
236 }
237
238 Rcolor[0] = CLAMP(diffuseColor[0], 0.0F, 1.0F);
239 Rcolor[1] = CLAMP(diffuseColor[1], 0.0F, 1.0F);
240 Rcolor[2] = CLAMP(diffuseColor[2], 0.0F, 1.0F);
241 Rcolor[3] = CLAMP(diffuseColor[3], 0.0F, 1.0F);
242 Rspec[0] = CLAMP(specularColor[0], 0.0F, 1.0F);
243 Rspec[1] = CLAMP(specularColor[1], 0.0F, 1.0F);
244 Rspec[2] = CLAMP(specularColor[2], 0.0F, 1.0F);
245 Rspec[3] = CLAMP(specularColor[3], 0.0F, 1.0F);
246 }
247
248
249 /**
250 * Do texgen needed for glRasterPos.
251 * \param ctx rendering context
252 * \param vObj object-space vertex coordinate
253 * \param vEye eye-space vertex coordinate
254 * \param normal vertex normal
255 * \param unit texture unit number
256 * \param texcoord incoming texcoord and resulting texcoord
257 */
258 static void
compute_texgen(struct gl_context * ctx,const GLfloat vObj[4],const GLfloat vEye[4],const GLfloat normal[3],GLuint unit,GLfloat texcoord[4])259 compute_texgen(struct gl_context *ctx, const GLfloat vObj[4], const GLfloat vEye[4],
260 const GLfloat normal[3], GLuint unit, GLfloat texcoord[4])
261 {
262 const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
263
264 /* always compute sphere map terms, just in case */
265 GLfloat u[3], two_nu, rx, ry, rz, m, mInv;
266 COPY_3V(u, vEye);
267 NORMALIZE_3FV(u);
268 two_nu = 2.0F * DOT3(normal, u);
269 rx = u[0] - normal[0] * two_nu;
270 ry = u[1] - normal[1] * two_nu;
271 rz = u[2] - normal[2] * two_nu;
272 m = rx * rx + ry * ry + (rz + 1.0F) * (rz + 1.0F);
273 if (m > 0.0F)
274 mInv = 0.5F * INV_SQRTF(m);
275 else
276 mInv = 0.0F;
277
278 if (texUnit->TexGenEnabled & S_BIT) {
279 switch (texUnit->GenS.Mode) {
280 case GL_OBJECT_LINEAR:
281 texcoord[0] = DOT4(vObj, texUnit->GenS.ObjectPlane);
282 break;
283 case GL_EYE_LINEAR:
284 texcoord[0] = DOT4(vEye, texUnit->GenS.EyePlane);
285 break;
286 case GL_SPHERE_MAP:
287 texcoord[0] = rx * mInv + 0.5F;
288 break;
289 case GL_REFLECTION_MAP:
290 texcoord[0] = rx;
291 break;
292 case GL_NORMAL_MAP:
293 texcoord[0] = normal[0];
294 break;
295 default:
296 _mesa_problem(ctx, "Bad S texgen in compute_texgen()");
297 return;
298 }
299 }
300
301 if (texUnit->TexGenEnabled & T_BIT) {
302 switch (texUnit->GenT.Mode) {
303 case GL_OBJECT_LINEAR:
304 texcoord[1] = DOT4(vObj, texUnit->GenT.ObjectPlane);
305 break;
306 case GL_EYE_LINEAR:
307 texcoord[1] = DOT4(vEye, texUnit->GenT.EyePlane);
308 break;
309 case GL_SPHERE_MAP:
310 texcoord[1] = ry * mInv + 0.5F;
311 break;
312 case GL_REFLECTION_MAP:
313 texcoord[1] = ry;
314 break;
315 case GL_NORMAL_MAP:
316 texcoord[1] = normal[1];
317 break;
318 default:
319 _mesa_problem(ctx, "Bad T texgen in compute_texgen()");
320 return;
321 }
322 }
323
324 if (texUnit->TexGenEnabled & R_BIT) {
325 switch (texUnit->GenR.Mode) {
326 case GL_OBJECT_LINEAR:
327 texcoord[2] = DOT4(vObj, texUnit->GenR.ObjectPlane);
328 break;
329 case GL_EYE_LINEAR:
330 texcoord[2] = DOT4(vEye, texUnit->GenR.EyePlane);
331 break;
332 case GL_REFLECTION_MAP:
333 texcoord[2] = rz;
334 break;
335 case GL_NORMAL_MAP:
336 texcoord[2] = normal[2];
337 break;
338 default:
339 _mesa_problem(ctx, "Bad R texgen in compute_texgen()");
340 return;
341 }
342 }
343
344 if (texUnit->TexGenEnabled & Q_BIT) {
345 switch (texUnit->GenQ.Mode) {
346 case GL_OBJECT_LINEAR:
347 texcoord[3] = DOT4(vObj, texUnit->GenQ.ObjectPlane);
348 break;
349 case GL_EYE_LINEAR:
350 texcoord[3] = DOT4(vEye, texUnit->GenQ.EyePlane);
351 break;
352 default:
353 _mesa_problem(ctx, "Bad Q texgen in compute_texgen()");
354 return;
355 }
356 }
357 }
358
359
360 /**
361 * glRasterPos transformation. Typically called via ctx->Driver.RasterPos().
362 * XXX some of this code (such as viewport xform, clip testing and setting
363 * of ctx->Current.Raster* fields) could get lifted up into the
364 * main/rasterpos.c code.
365 *
366 * \param vObj vertex position in object space
367 */
368 void
_tnl_RasterPos(struct gl_context * ctx,const GLfloat vObj[4])369 _tnl_RasterPos(struct gl_context *ctx, const GLfloat vObj[4])
370 {
371 if (ctx->VertexProgram._Enabled) {
372 /* XXX implement this */
373 _mesa_problem(ctx, "Vertex programs not implemented for glRasterPos");
374 return;
375 }
376 else {
377 GLfloat eye[4], clip[4], ndc[3], d;
378 GLfloat *norm, eyenorm[3];
379 GLfloat *objnorm = ctx->Current.Attrib[VERT_ATTRIB_NORMAL];
380
381 /* apply modelview matrix: eye = MV * obj */
382 TRANSFORM_POINT( eye, ctx->ModelviewMatrixStack.Top->m, vObj );
383 /* apply projection matrix: clip = Proj * eye */
384 TRANSFORM_POINT( clip, ctx->ProjectionMatrixStack.Top->m, eye );
385
386 /* clip to view volume. */
387 if (!ctx->Transform.DepthClamp) {
388 if (viewclip_point_z(clip) == 0) {
389 ctx->Current.RasterPosValid = GL_FALSE;
390 return;
391 }
392 }
393 if (!ctx->Transform.RasterPositionUnclipped) {
394 if (viewclip_point_xy(clip) == 0) {
395 ctx->Current.RasterPosValid = GL_FALSE;
396 return;
397 }
398 }
399
400 /* clip to user clipping planes */
401 if (ctx->Transform.ClipPlanesEnabled && !userclip_point(ctx, clip)) {
402 ctx->Current.RasterPosValid = GL_FALSE;
403 return;
404 }
405
406 /* ndc = clip / W */
407 d = (clip[3] == 0.0F) ? 1.0F : 1.0F / clip[3];
408 ndc[0] = clip[0] * d;
409 ndc[1] = clip[1] * d;
410 ndc[2] = clip[2] * d;
411 /* wincoord = viewport_mapping(ndc) */
412 ctx->Current.RasterPos[0] = (ndc[0] * ctx->Viewport._WindowMap.m[MAT_SX]
413 + ctx->Viewport._WindowMap.m[MAT_TX]);
414 ctx->Current.RasterPos[1] = (ndc[1] * ctx->Viewport._WindowMap.m[MAT_SY]
415 + ctx->Viewport._WindowMap.m[MAT_TY]);
416 ctx->Current.RasterPos[2] = (ndc[2] * ctx->Viewport._WindowMap.m[MAT_SZ]
417 + ctx->Viewport._WindowMap.m[MAT_TZ])
418 / ctx->DrawBuffer->_DepthMaxF;
419 ctx->Current.RasterPos[3] = clip[3];
420
421 if (ctx->Transform.DepthClamp) {
422 ctx->Current.RasterPos[3] = CLAMP(ctx->Current.RasterPos[3],
423 ctx->Viewport.Near,
424 ctx->Viewport.Far);
425 }
426
427 /* compute raster distance */
428 if (ctx->Fog.FogCoordinateSource == GL_FOG_COORDINATE_EXT)
429 ctx->Current.RasterDistance = ctx->Current.Attrib[VERT_ATTRIB_FOG][0];
430 else
431 ctx->Current.RasterDistance =
432 SQRTF( eye[0]*eye[0] + eye[1]*eye[1] + eye[2]*eye[2] );
433
434 /* compute transformed normal vector (for lighting or texgen) */
435 if (ctx->_NeedEyeCoords) {
436 const GLfloat *inv = ctx->ModelviewMatrixStack.Top->inv;
437 TRANSFORM_NORMAL( eyenorm, objnorm, inv );
438 norm = eyenorm;
439 }
440 else {
441 norm = objnorm;
442 }
443
444 /* update raster color */
445 if (ctx->Light.Enabled) {
446 /* lighting */
447 shade_rastpos( ctx, vObj, norm,
448 ctx->Current.RasterColor,
449 ctx->Current.RasterSecondaryColor );
450 }
451 else {
452 /* use current color */
453 COPY_4FV(ctx->Current.RasterColor,
454 ctx->Current.Attrib[VERT_ATTRIB_COLOR0]);
455 COPY_4FV(ctx->Current.RasterSecondaryColor,
456 ctx->Current.Attrib[VERT_ATTRIB_COLOR1]);
457 }
458
459 /* texture coords */
460 {
461 GLuint u;
462 for (u = 0; u < ctx->Const.MaxTextureCoordUnits; u++) {
463 GLfloat tc[4];
464 COPY_4V(tc, ctx->Current.Attrib[VERT_ATTRIB_TEX0 + u]);
465 if (ctx->Texture.Unit[u].TexGenEnabled) {
466 compute_texgen(ctx, vObj, eye, norm, u, tc);
467 }
468 TRANSFORM_POINT(ctx->Current.RasterTexCoords[u],
469 ctx->TextureMatrixStack[u].Top->m, tc);
470 }
471 }
472
473 ctx->Current.RasterPosValid = GL_TRUE;
474 }
475
476 if (ctx->RenderMode == GL_SELECT) {
477 _mesa_update_hitflag( ctx, ctx->Current.RasterPos[2] );
478 }
479 }
480