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1 /**
2  * \file blend.c
3  * Blending operations.
4  */
5 
6 /*
7  * Mesa 3-D graphics library
8  *
9  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
10  *
11  * Permission is hereby granted, free of charge, to any person obtaining a
12  * copy of this software and associated documentation files (the "Software"),
13  * to deal in the Software without restriction, including without limitation
14  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
15  * and/or sell copies of the Software, and to permit persons to whom the
16  * Software is furnished to do so, subject to the following conditions:
17  *
18  * The above copyright notice and this permission notice shall be included
19  * in all copies or substantial portions of the Software.
20  *
21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
22  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
23  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
24  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
25  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
26  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
27  * OTHER DEALINGS IN THE SOFTWARE.
28  */
29 
30 
31 
32 #include "glheader.h"
33 #include "blend.h"
34 #include "context.h"
35 #include "enums.h"
36 #include "macros.h"
37 #include "mtypes.h"
38 
39 
40 
41 /**
42  * Check if given blend source factor is legal.
43  * \return GL_TRUE if legal, GL_FALSE otherwise.
44  */
45 static GLboolean
legal_src_factor(const struct gl_context * ctx,GLenum factor)46 legal_src_factor(const struct gl_context *ctx, GLenum factor)
47 {
48    switch (factor) {
49    case GL_SRC_COLOR:
50    case GL_ONE_MINUS_SRC_COLOR:
51    case GL_ZERO:
52    case GL_ONE:
53    case GL_DST_COLOR:
54    case GL_ONE_MINUS_DST_COLOR:
55    case GL_SRC_ALPHA:
56    case GL_ONE_MINUS_SRC_ALPHA:
57    case GL_DST_ALPHA:
58    case GL_ONE_MINUS_DST_ALPHA:
59    case GL_SRC_ALPHA_SATURATE:
60       return GL_TRUE;
61    case GL_CONSTANT_COLOR:
62    case GL_ONE_MINUS_CONSTANT_COLOR:
63    case GL_CONSTANT_ALPHA:
64    case GL_ONE_MINUS_CONSTANT_ALPHA:
65       return _mesa_is_desktop_gl(ctx) || ctx->API == API_OPENGLES2;
66    case GL_SRC1_COLOR:
67    case GL_SRC1_ALPHA:
68    case GL_ONE_MINUS_SRC1_COLOR:
69    case GL_ONE_MINUS_SRC1_ALPHA:
70       return ctx->API != API_OPENGLES
71          && ctx->Extensions.ARB_blend_func_extended;
72    default:
73       return GL_FALSE;
74    }
75 }
76 
77 
78 /**
79  * Check if given blend destination factor is legal.
80  * \return GL_TRUE if legal, GL_FALSE otherwise.
81  */
82 static GLboolean
legal_dst_factor(const struct gl_context * ctx,GLenum factor)83 legal_dst_factor(const struct gl_context *ctx, GLenum factor)
84 {
85    switch (factor) {
86    case GL_DST_COLOR:
87    case GL_ONE_MINUS_DST_COLOR:
88    case GL_ZERO:
89    case GL_ONE:
90    case GL_SRC_COLOR:
91    case GL_ONE_MINUS_SRC_COLOR:
92    case GL_SRC_ALPHA:
93    case GL_ONE_MINUS_SRC_ALPHA:
94    case GL_DST_ALPHA:
95    case GL_ONE_MINUS_DST_ALPHA:
96       return GL_TRUE;
97    case GL_CONSTANT_COLOR:
98    case GL_ONE_MINUS_CONSTANT_COLOR:
99    case GL_CONSTANT_ALPHA:
100    case GL_ONE_MINUS_CONSTANT_ALPHA:
101       return _mesa_is_desktop_gl(ctx) || ctx->API == API_OPENGLES2;
102    case GL_SRC_ALPHA_SATURATE:
103       return (ctx->API != API_OPENGLES
104               && ctx->Extensions.ARB_blend_func_extended)
105          || _mesa_is_gles3(ctx);
106    case GL_SRC1_COLOR:
107    case GL_SRC1_ALPHA:
108    case GL_ONE_MINUS_SRC1_COLOR:
109    case GL_ONE_MINUS_SRC1_ALPHA:
110       return ctx->API != API_OPENGLES
111          && ctx->Extensions.ARB_blend_func_extended;
112    default:
113       return GL_FALSE;
114    }
115 }
116 
117 
118 /**
119  * Check if src/dest RGB/A blend factors are legal.  If not generate
120  * a GL error.
121  * \return GL_TRUE if factors are legal, GL_FALSE otherwise.
122  */
123 static GLboolean
validate_blend_factors(struct gl_context * ctx,const char * func,GLenum sfactorRGB,GLenum dfactorRGB,GLenum sfactorA,GLenum dfactorA)124 validate_blend_factors(struct gl_context *ctx, const char *func,
125                        GLenum sfactorRGB, GLenum dfactorRGB,
126                        GLenum sfactorA, GLenum dfactorA)
127 {
128    if (!legal_src_factor(ctx, sfactorRGB)) {
129       _mesa_error(ctx, GL_INVALID_ENUM,
130                   "%s(sfactorRGB = %s)", func,
131                   _mesa_enum_to_string(sfactorRGB));
132       return GL_FALSE;
133    }
134 
135    if (!legal_dst_factor(ctx, dfactorRGB)) {
136       _mesa_error(ctx, GL_INVALID_ENUM,
137                   "%s(dfactorRGB = %s)", func,
138                   _mesa_enum_to_string(dfactorRGB));
139       return GL_FALSE;
140    }
141 
142    if (sfactorA != sfactorRGB && !legal_src_factor(ctx, sfactorA)) {
143       _mesa_error(ctx, GL_INVALID_ENUM,
144                   "%s(sfactorA = %s)", func,
145                   _mesa_enum_to_string(sfactorA));
146       return GL_FALSE;
147    }
148 
149    if (dfactorA != dfactorRGB && !legal_dst_factor(ctx, dfactorA)) {
150       _mesa_error(ctx, GL_INVALID_ENUM,
151                   "%s(dfactorA = %s)", func,
152                   _mesa_enum_to_string(dfactorA));
153       return GL_FALSE;
154    }
155 
156    return GL_TRUE;
157 }
158 
159 
160 /**
161  * Specify the blending operation.
162  *
163  * \param sfactor source factor operator.
164  * \param dfactor destination factor operator.
165  *
166  * \sa glBlendFunc, glBlendFuncSeparateEXT
167  */
168 void GLAPIENTRY
_mesa_BlendFunc(GLenum sfactor,GLenum dfactor)169 _mesa_BlendFunc( GLenum sfactor, GLenum dfactor )
170 {
171    _mesa_BlendFuncSeparate(sfactor, dfactor, sfactor, dfactor);
172 }
173 
174 static GLboolean
blend_factor_is_dual_src(GLenum factor)175 blend_factor_is_dual_src(GLenum factor)
176 {
177    return (factor == GL_SRC1_COLOR ||
178 	   factor == GL_SRC1_ALPHA ||
179 	   factor == GL_ONE_MINUS_SRC1_COLOR ||
180 	   factor == GL_ONE_MINUS_SRC1_ALPHA);
181 }
182 
183 static void
update_uses_dual_src(struct gl_context * ctx,int buf)184 update_uses_dual_src(struct gl_context *ctx, int buf)
185 {
186    ctx->Color.Blend[buf]._UsesDualSrc =
187       (blend_factor_is_dual_src(ctx->Color.Blend[buf].SrcRGB) ||
188        blend_factor_is_dual_src(ctx->Color.Blend[buf].DstRGB) ||
189        blend_factor_is_dual_src(ctx->Color.Blend[buf].SrcA) ||
190        blend_factor_is_dual_src(ctx->Color.Blend[buf].DstA));
191 }
192 
193 
194 /**
195  * Return the number of per-buffer blend states to update in
196  * glBlendFunc, glBlendFuncSeparate, glBlendEquation, etc.
197  */
198 static inline unsigned
num_buffers(const struct gl_context * ctx)199 num_buffers(const struct gl_context *ctx)
200 {
201    return ctx->Extensions.ARB_draw_buffers_blend
202       ? ctx->Const.MaxDrawBuffers : 1;
203 }
204 
205 
206 /**
207  * Set the separate blend source/dest factors for all draw buffers.
208  *
209  * \param sfactorRGB RGB source factor operator.
210  * \param dfactorRGB RGB destination factor operator.
211  * \param sfactorA alpha source factor operator.
212  * \param dfactorA alpha destination factor operator.
213  */
214 void GLAPIENTRY
_mesa_BlendFuncSeparate(GLenum sfactorRGB,GLenum dfactorRGB,GLenum sfactorA,GLenum dfactorA)215 _mesa_BlendFuncSeparate( GLenum sfactorRGB, GLenum dfactorRGB,
216                             GLenum sfactorA, GLenum dfactorA )
217 {
218    GET_CURRENT_CONTEXT(ctx);
219    const unsigned numBuffers = num_buffers(ctx);
220    unsigned buf;
221    bool changed = false;
222 
223    if (MESA_VERBOSE & VERBOSE_API)
224       _mesa_debug(ctx, "glBlendFuncSeparate %s %s %s %s\n",
225                   _mesa_enum_to_string(sfactorRGB),
226                   _mesa_enum_to_string(dfactorRGB),
227                   _mesa_enum_to_string(sfactorA),
228                   _mesa_enum_to_string(dfactorA));
229 
230    /* Check if we're really changing any state.  If not, return early. */
231    if (ctx->Color._BlendFuncPerBuffer) {
232       /* Check all per-buffer states */
233       for (buf = 0; buf < numBuffers; buf++) {
234          if (ctx->Color.Blend[buf].SrcRGB != sfactorRGB ||
235              ctx->Color.Blend[buf].DstRGB != dfactorRGB ||
236              ctx->Color.Blend[buf].SrcA != sfactorA ||
237              ctx->Color.Blend[buf].DstA != dfactorA) {
238             changed = true;
239             break;
240          }
241       }
242    }
243    else {
244       /* only need to check 0th per-buffer state */
245       if (ctx->Color.Blend[0].SrcRGB != sfactorRGB ||
246           ctx->Color.Blend[0].DstRGB != dfactorRGB ||
247           ctx->Color.Blend[0].SrcA != sfactorA ||
248           ctx->Color.Blend[0].DstA != dfactorA) {
249          changed = true;
250       }
251    }
252 
253    if (!changed)
254       return;
255 
256    if (!validate_blend_factors(ctx, "glBlendFuncSeparate",
257                                sfactorRGB, dfactorRGB,
258                                sfactorA, dfactorA)) {
259       return;
260    }
261 
262    FLUSH_VERTICES(ctx, _NEW_COLOR);
263 
264    for (buf = 0; buf < numBuffers; buf++) {
265       ctx->Color.Blend[buf].SrcRGB = sfactorRGB;
266       ctx->Color.Blend[buf].DstRGB = dfactorRGB;
267       ctx->Color.Blend[buf].SrcA = sfactorA;
268       ctx->Color.Blend[buf].DstA = dfactorA;
269    }
270 
271    update_uses_dual_src(ctx, 0);
272    for (buf = 1; buf < numBuffers; buf++) {
273       ctx->Color.Blend[buf]._UsesDualSrc = ctx->Color.Blend[0]._UsesDualSrc;
274    }
275 
276    ctx->Color._BlendFuncPerBuffer = GL_FALSE;
277 
278    if (ctx->Driver.BlendFuncSeparate) {
279       ctx->Driver.BlendFuncSeparate(ctx, sfactorRGB, dfactorRGB,
280                                     sfactorA, dfactorA);
281    }
282 }
283 
284 
285 /**
286  * Set blend source/dest factors for one color buffer/target.
287  */
288 void GLAPIENTRY
_mesa_BlendFunciARB(GLuint buf,GLenum sfactor,GLenum dfactor)289 _mesa_BlendFunciARB(GLuint buf, GLenum sfactor, GLenum dfactor)
290 {
291    _mesa_BlendFuncSeparateiARB(buf, sfactor, dfactor, sfactor, dfactor);
292 }
293 
294 
295 /**
296  * Set separate blend source/dest factors for one color buffer/target.
297  */
298 void GLAPIENTRY
_mesa_BlendFuncSeparateiARB(GLuint buf,GLenum sfactorRGB,GLenum dfactorRGB,GLenum sfactorA,GLenum dfactorA)299 _mesa_BlendFuncSeparateiARB(GLuint buf, GLenum sfactorRGB, GLenum dfactorRGB,
300                          GLenum sfactorA, GLenum dfactorA)
301 {
302    GET_CURRENT_CONTEXT(ctx);
303 
304    if (!ctx->Extensions.ARB_draw_buffers_blend) {
305       _mesa_error(ctx, GL_INVALID_OPERATION, "glBlendFunc[Separate]i()");
306       return;
307    }
308 
309    if (buf >= ctx->Const.MaxDrawBuffers) {
310       _mesa_error(ctx, GL_INVALID_VALUE, "glBlendFuncSeparatei(buffer=%u)",
311                   buf);
312       return;
313    }
314 
315    if (ctx->Color.Blend[buf].SrcRGB == sfactorRGB &&
316        ctx->Color.Blend[buf].DstRGB == dfactorRGB &&
317        ctx->Color.Blend[buf].SrcA == sfactorA &&
318        ctx->Color.Blend[buf].DstA == dfactorA)
319       return; /* no change */
320 
321    if (!validate_blend_factors(ctx, "glBlendFuncSeparatei",
322                                sfactorRGB, dfactorRGB,
323                                sfactorA, dfactorA)) {
324       return;
325    }
326 
327    FLUSH_VERTICES(ctx, _NEW_COLOR);
328 
329    ctx->Color.Blend[buf].SrcRGB = sfactorRGB;
330    ctx->Color.Blend[buf].DstRGB = dfactorRGB;
331    ctx->Color.Blend[buf].SrcA = sfactorA;
332    ctx->Color.Blend[buf].DstA = dfactorA;
333    update_uses_dual_src(ctx, buf);
334    ctx->Color._BlendFuncPerBuffer = GL_TRUE;
335 }
336 
337 
338 /**
339  * Return true if \p mode is a legal blending equation, excluding
340  * GL_KHR_blend_equation_advanced modes.
341  */
342 static bool
legal_simple_blend_equation(const struct gl_context * ctx,GLenum mode)343 legal_simple_blend_equation(const struct gl_context *ctx, GLenum mode)
344 {
345    switch (mode) {
346    case GL_FUNC_ADD:
347    case GL_FUNC_SUBTRACT:
348    case GL_FUNC_REVERSE_SUBTRACT:
349       return GL_TRUE;
350    case GL_MIN:
351    case GL_MAX:
352       return ctx->Extensions.EXT_blend_minmax;
353    default:
354       return GL_FALSE;
355    }
356 }
357 
358 static enum gl_advanced_blend_mode
advanced_blend_mode_from_gl_enum(GLenum mode)359 advanced_blend_mode_from_gl_enum(GLenum mode)
360 {
361    switch (mode) {
362    case GL_MULTIPLY_KHR:
363       return BLEND_MULTIPLY;
364    case GL_SCREEN_KHR:
365       return BLEND_SCREEN;
366    case GL_OVERLAY_KHR:
367       return BLEND_OVERLAY;
368    case GL_DARKEN_KHR:
369       return BLEND_DARKEN;
370    case GL_LIGHTEN_KHR:
371       return BLEND_LIGHTEN;
372    case GL_COLORDODGE_KHR:
373       return BLEND_COLORDODGE;
374    case GL_COLORBURN_KHR:
375       return BLEND_COLORBURN;
376    case GL_HARDLIGHT_KHR:
377       return BLEND_HARDLIGHT;
378    case GL_SOFTLIGHT_KHR:
379       return BLEND_SOFTLIGHT;
380    case GL_DIFFERENCE_KHR:
381       return BLEND_DIFFERENCE;
382    case GL_EXCLUSION_KHR:
383       return BLEND_EXCLUSION;
384    case GL_HSL_HUE_KHR:
385       return BLEND_HSL_HUE;
386    case GL_HSL_SATURATION_KHR:
387       return BLEND_HSL_SATURATION;
388    case GL_HSL_COLOR_KHR:
389       return BLEND_HSL_COLOR;
390    case GL_HSL_LUMINOSITY_KHR:
391       return BLEND_HSL_LUMINOSITY;
392    default:
393       return BLEND_NONE;
394    }
395 }
396 
397 /**
398  * If \p mode is one of the advanced blending equations defined by
399  * GL_KHR_blend_equation_advanced (and the extension is supported),
400  * return the corresponding BLEND_* enum.  Otherwise, return BLEND_NONE
401  * (which can also be treated as false).
402  */
403 static enum gl_advanced_blend_mode
advanced_blend_mode(const struct gl_context * ctx,GLenum mode)404 advanced_blend_mode(const struct gl_context *ctx, GLenum mode)
405 {
406    return _mesa_has_KHR_blend_equation_advanced(ctx) ?
407           advanced_blend_mode_from_gl_enum(mode) : BLEND_NONE;
408 }
409 
410 /* This is really an extension function! */
411 void GLAPIENTRY
_mesa_BlendEquation(GLenum mode)412 _mesa_BlendEquation( GLenum mode )
413 {
414    GET_CURRENT_CONTEXT(ctx);
415    const unsigned numBuffers = num_buffers(ctx);
416    unsigned buf;
417    bool changed = false;
418    enum gl_advanced_blend_mode advanced_mode = advanced_blend_mode(ctx, mode);
419 
420    if (MESA_VERBOSE & VERBOSE_API)
421       _mesa_debug(ctx, "glBlendEquation(%s)\n",
422                   _mesa_enum_to_string(mode));
423 
424    if (ctx->Color._BlendEquationPerBuffer) {
425       /* Check all per-buffer states */
426       for (buf = 0; buf < numBuffers; buf++) {
427          if (ctx->Color.Blend[buf].EquationRGB != mode ||
428              ctx->Color.Blend[buf].EquationA != mode) {
429             changed = true;
430             break;
431          }
432       }
433    }
434    else {
435       /* only need to check 0th per-buffer state */
436       if (ctx->Color.Blend[0].EquationRGB != mode ||
437           ctx->Color.Blend[0].EquationA != mode) {
438          changed = true;
439       }
440    }
441 
442    if (!changed)
443       return;
444 
445 
446    if (!legal_simple_blend_equation(ctx, mode) && !advanced_mode) {
447       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquation");
448       return;
449    }
450 
451    FLUSH_VERTICES(ctx, _NEW_COLOR);
452 
453    for (buf = 0; buf < numBuffers; buf++) {
454       ctx->Color.Blend[buf].EquationRGB = mode;
455       ctx->Color.Blend[buf].EquationA = mode;
456    }
457    ctx->Color._BlendEquationPerBuffer = GL_FALSE;
458    ctx->Color._AdvancedBlendMode = advanced_mode;
459 
460    if (ctx->Driver.BlendEquationSeparate)
461       ctx->Driver.BlendEquationSeparate(ctx, mode, mode);
462 }
463 
464 
465 /**
466  * Set blend equation for one color buffer/target.
467  */
468 void GLAPIENTRY
_mesa_BlendEquationiARB(GLuint buf,GLenum mode)469 _mesa_BlendEquationiARB(GLuint buf, GLenum mode)
470 {
471    GET_CURRENT_CONTEXT(ctx);
472    enum gl_advanced_blend_mode advanced_mode = advanced_blend_mode(ctx, mode);
473 
474    if (MESA_VERBOSE & VERBOSE_API)
475       _mesa_debug(ctx, "glBlendEquationi(%u, %s)\n",
476                   buf, _mesa_enum_to_string(mode));
477 
478    if (buf >= ctx->Const.MaxDrawBuffers) {
479       _mesa_error(ctx, GL_INVALID_VALUE, "glBlendEquationi(buffer=%u)",
480                   buf);
481       return;
482    }
483 
484    if (!legal_simple_blend_equation(ctx, mode) && !advanced_mode) {
485       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationi");
486       return;
487    }
488 
489    if (ctx->Color.Blend[buf].EquationRGB == mode &&
490        ctx->Color.Blend[buf].EquationA == mode)
491       return;  /* no change */
492 
493    FLUSH_VERTICES(ctx, _NEW_COLOR);
494    ctx->Color.Blend[buf].EquationRGB = mode;
495    ctx->Color.Blend[buf].EquationA = mode;
496    ctx->Color._BlendEquationPerBuffer = GL_TRUE;
497 
498    if (buf == 0)
499       ctx->Color._AdvancedBlendMode = advanced_mode;
500 }
501 
502 
503 void GLAPIENTRY
_mesa_BlendEquationSeparate(GLenum modeRGB,GLenum modeA)504 _mesa_BlendEquationSeparate( GLenum modeRGB, GLenum modeA )
505 {
506    GET_CURRENT_CONTEXT(ctx);
507    const unsigned numBuffers = num_buffers(ctx);
508    unsigned buf;
509    bool changed = false;
510 
511    if (MESA_VERBOSE & VERBOSE_API)
512       _mesa_debug(ctx, "glBlendEquationSeparateEXT(%s %s)\n",
513                   _mesa_enum_to_string(modeRGB),
514                   _mesa_enum_to_string(modeA));
515 
516    if (ctx->Color._BlendEquationPerBuffer) {
517       /* Check all per-buffer states */
518       for (buf = 0; buf < numBuffers; buf++) {
519          if (ctx->Color.Blend[buf].EquationRGB != modeRGB ||
520              ctx->Color.Blend[buf].EquationA != modeA) {
521             changed = true;
522             break;
523          }
524       }
525    }
526    else {
527       /* only need to check 0th per-buffer state */
528       if (ctx->Color.Blend[0].EquationRGB != modeRGB ||
529           ctx->Color.Blend[0].EquationA != modeA) {
530          changed = true;
531       }
532    }
533 
534    if (!changed)
535       return;
536 
537    if ( (modeRGB != modeA) && !ctx->Extensions.EXT_blend_equation_separate ) {
538       _mesa_error(ctx, GL_INVALID_OPERATION,
539 		  "glBlendEquationSeparateEXT not supported by driver");
540       return;
541    }
542 
543    /* Only allow simple blending equations.
544     * The GL_KHR_blend_equation_advanced spec says:
545     *
546     *    "NOTE: These enums are not accepted by the <modeRGB> or <modeAlpha>
547     *     parameters of BlendEquationSeparate or BlendEquationSeparatei."
548     */
549    if (!legal_simple_blend_equation(ctx, modeRGB)) {
550       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparateEXT(modeRGB)");
551       return;
552    }
553 
554    if (!legal_simple_blend_equation(ctx, modeA)) {
555       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparateEXT(modeA)");
556       return;
557    }
558 
559    FLUSH_VERTICES(ctx, _NEW_COLOR);
560 
561    for (buf = 0; buf < numBuffers; buf++) {
562       ctx->Color.Blend[buf].EquationRGB = modeRGB;
563       ctx->Color.Blend[buf].EquationA = modeA;
564    }
565    ctx->Color._BlendEquationPerBuffer = GL_FALSE;
566    ctx->Color._AdvancedBlendMode = BLEND_NONE;
567 
568    if (ctx->Driver.BlendEquationSeparate)
569       ctx->Driver.BlendEquationSeparate(ctx, modeRGB, modeA);
570 }
571 
572 
573 /**
574  * Set separate blend equations for one color buffer/target.
575  */
576 void GLAPIENTRY
_mesa_BlendEquationSeparateiARB(GLuint buf,GLenum modeRGB,GLenum modeA)577 _mesa_BlendEquationSeparateiARB(GLuint buf, GLenum modeRGB, GLenum modeA)
578 {
579    GET_CURRENT_CONTEXT(ctx);
580 
581    if (MESA_VERBOSE & VERBOSE_API)
582       _mesa_debug(ctx, "glBlendEquationSeparatei(%u, %s %s)\n", buf,
583                   _mesa_enum_to_string(modeRGB),
584                   _mesa_enum_to_string(modeA));
585 
586    if (buf >= ctx->Const.MaxDrawBuffers) {
587       _mesa_error(ctx, GL_INVALID_VALUE, "glBlendEquationSeparatei(buffer=%u)",
588                   buf);
589       return;
590    }
591 
592    /* Only allow simple blending equations.
593     * The GL_KHR_blend_equation_advanced spec says:
594     *
595     *    "NOTE: These enums are not accepted by the <modeRGB> or <modeAlpha>
596     *     parameters of BlendEquationSeparate or BlendEquationSeparatei."
597     */
598    if (!legal_simple_blend_equation(ctx, modeRGB)) {
599       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparatei(modeRGB)");
600       return;
601    }
602 
603    if (!legal_simple_blend_equation(ctx, modeA)) {
604       _mesa_error(ctx, GL_INVALID_ENUM, "glBlendEquationSeparatei(modeA)");
605       return;
606    }
607 
608    if (ctx->Color.Blend[buf].EquationRGB == modeRGB &&
609        ctx->Color.Blend[buf].EquationA == modeA)
610       return;  /* no change */
611 
612    FLUSH_VERTICES(ctx, _NEW_COLOR);
613    ctx->Color.Blend[buf].EquationRGB = modeRGB;
614    ctx->Color.Blend[buf].EquationA = modeA;
615    ctx->Color._BlendEquationPerBuffer = GL_TRUE;
616    ctx->Color._AdvancedBlendMode = BLEND_NONE;
617 }
618 
619 
620 /**
621  * Set the blending color.
622  *
623  * \param red red color component.
624  * \param green green color component.
625  * \param blue blue color component.
626  * \param alpha alpha color component.
627  *
628  * \sa glBlendColor().
629  *
630  * Clamps the parameters and updates gl_colorbuffer_attrib::BlendColor.  On a
631  * change, flushes the vertices and notifies the driver via
632  * dd_function_table::BlendColor callback.
633  */
634 void GLAPIENTRY
_mesa_BlendColor(GLclampf red,GLclampf green,GLclampf blue,GLclampf alpha)635 _mesa_BlendColor( GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha )
636 {
637    GLfloat tmp[4];
638    GET_CURRENT_CONTEXT(ctx);
639 
640    tmp[0] = red;
641    tmp[1] = green;
642    tmp[2] = blue;
643    tmp[3] = alpha;
644 
645    if (TEST_EQ_4V(tmp, ctx->Color.BlendColorUnclamped))
646       return;
647 
648    FLUSH_VERTICES(ctx, _NEW_COLOR);
649    COPY_4FV( ctx->Color.BlendColorUnclamped, tmp );
650 
651    ctx->Color.BlendColor[0] = CLAMP(tmp[0], 0.0F, 1.0F);
652    ctx->Color.BlendColor[1] = CLAMP(tmp[1], 0.0F, 1.0F);
653    ctx->Color.BlendColor[2] = CLAMP(tmp[2], 0.0F, 1.0F);
654    ctx->Color.BlendColor[3] = CLAMP(tmp[3], 0.0F, 1.0F);
655 
656    if (ctx->Driver.BlendColor)
657       ctx->Driver.BlendColor(ctx, ctx->Color.BlendColor);
658 }
659 
660 
661 /**
662  * Specify the alpha test function.
663  *
664  * \param func alpha comparison function.
665  * \param ref reference value.
666  *
667  * Verifies the parameters and updates gl_colorbuffer_attrib.
668  * On a change, flushes the vertices and notifies the driver via
669  * dd_function_table::AlphaFunc callback.
670  */
671 void GLAPIENTRY
_mesa_AlphaFunc(GLenum func,GLclampf ref)672 _mesa_AlphaFunc( GLenum func, GLclampf ref )
673 {
674    GET_CURRENT_CONTEXT(ctx);
675 
676    if (MESA_VERBOSE & VERBOSE_API)
677       _mesa_debug(ctx, "glAlphaFunc(%s, %f)\n",
678                   _mesa_enum_to_string(func), ref);
679 
680    if (ctx->Color.AlphaFunc == func && ctx->Color.AlphaRefUnclamped == ref)
681       return; /* no change */
682 
683    switch (func) {
684    case GL_NEVER:
685    case GL_LESS:
686    case GL_EQUAL:
687    case GL_LEQUAL:
688    case GL_GREATER:
689    case GL_NOTEQUAL:
690    case GL_GEQUAL:
691    case GL_ALWAYS:
692       FLUSH_VERTICES(ctx, _NEW_COLOR);
693       ctx->Color.AlphaFunc = func;
694       ctx->Color.AlphaRefUnclamped = ref;
695       ctx->Color.AlphaRef = CLAMP(ref, 0.0F, 1.0F);
696 
697       if (ctx->Driver.AlphaFunc)
698          ctx->Driver.AlphaFunc(ctx, func, ctx->Color.AlphaRef);
699       return;
700 
701    default:
702       _mesa_error( ctx, GL_INVALID_ENUM, "glAlphaFunc(func)" );
703       return;
704    }
705 }
706 
707 
708 /**
709  * Specify a logic pixel operation for color index rendering.
710  *
711  * \param opcode operation.
712  *
713  * Verifies that \p opcode is a valid enum and updates
714  * gl_colorbuffer_attrib::LogicOp.
715  * On a change, flushes the vertices and notifies the driver via the
716  * dd_function_table::LogicOpcode callback.
717  */
718 void GLAPIENTRY
_mesa_LogicOp(GLenum opcode)719 _mesa_LogicOp( GLenum opcode )
720 {
721    GET_CURRENT_CONTEXT(ctx);
722 
723    if (MESA_VERBOSE & VERBOSE_API)
724       _mesa_debug(ctx, "glLogicOp(%s)\n", _mesa_enum_to_string(opcode));
725 
726    switch (opcode) {
727       case GL_CLEAR:
728       case GL_SET:
729       case GL_COPY:
730       case GL_COPY_INVERTED:
731       case GL_NOOP:
732       case GL_INVERT:
733       case GL_AND:
734       case GL_NAND:
735       case GL_OR:
736       case GL_NOR:
737       case GL_XOR:
738       case GL_EQUIV:
739       case GL_AND_REVERSE:
740       case GL_AND_INVERTED:
741       case GL_OR_REVERSE:
742       case GL_OR_INVERTED:
743 	 break;
744       default:
745          _mesa_error( ctx, GL_INVALID_ENUM, "glLogicOp" );
746 	 return;
747    }
748 
749    if (ctx->Color.LogicOp == opcode)
750       return;
751 
752    FLUSH_VERTICES(ctx, _NEW_COLOR);
753    ctx->Color.LogicOp = opcode;
754 
755    if (ctx->Driver.LogicOpcode)
756       ctx->Driver.LogicOpcode( ctx, opcode );
757 }
758 
759 
760 void GLAPIENTRY
_mesa_IndexMask(GLuint mask)761 _mesa_IndexMask( GLuint mask )
762 {
763    GET_CURRENT_CONTEXT(ctx);
764 
765    if (ctx->Color.IndexMask == mask)
766       return;
767 
768    FLUSH_VERTICES(ctx, _NEW_COLOR);
769    ctx->Color.IndexMask = mask;
770 }
771 
772 
773 /**
774  * Enable or disable writing of frame buffer color components.
775  *
776  * \param red whether to mask writing of the red color component.
777  * \param green whether to mask writing of the green color component.
778  * \param blue whether to mask writing of the blue color component.
779  * \param alpha whether to mask writing of the alpha color component.
780  *
781  * \sa glColorMask().
782  *
783  * Sets the appropriate value of gl_colorbuffer_attrib::ColorMask.  On a
784  * change, flushes the vertices and notifies the driver via the
785  * dd_function_table::ColorMask callback.
786  */
787 void GLAPIENTRY
_mesa_ColorMask(GLboolean red,GLboolean green,GLboolean blue,GLboolean alpha)788 _mesa_ColorMask( GLboolean red, GLboolean green,
789                  GLboolean blue, GLboolean alpha )
790 {
791    GET_CURRENT_CONTEXT(ctx);
792    GLubyte tmp[4];
793    GLuint i;
794    GLboolean flushed;
795 
796    if (MESA_VERBOSE & VERBOSE_API)
797       _mesa_debug(ctx, "glColorMask(%d, %d, %d, %d)\n",
798                   red, green, blue, alpha);
799 
800    /* Shouldn't have any information about channel depth in core mesa
801     * -- should probably store these as the native booleans:
802     */
803    tmp[RCOMP] = red    ? 0xff : 0x0;
804    tmp[GCOMP] = green  ? 0xff : 0x0;
805    tmp[BCOMP] = blue   ? 0xff : 0x0;
806    tmp[ACOMP] = alpha  ? 0xff : 0x0;
807 
808    flushed = GL_FALSE;
809    for (i = 0; i < ctx->Const.MaxDrawBuffers; i++) {
810       if (!TEST_EQ_4V(tmp, ctx->Color.ColorMask[i])) {
811          if (!flushed) {
812             FLUSH_VERTICES(ctx, _NEW_COLOR);
813          }
814          flushed = GL_TRUE;
815          COPY_4UBV(ctx->Color.ColorMask[i], tmp);
816       }
817    }
818 
819    if (ctx->Driver.ColorMask)
820       ctx->Driver.ColorMask( ctx, red, green, blue, alpha );
821 }
822 
823 
824 /**
825  * For GL_EXT_draw_buffers2 and GL3
826  */
827 void GLAPIENTRY
_mesa_ColorMaski(GLuint buf,GLboolean red,GLboolean green,GLboolean blue,GLboolean alpha)828 _mesa_ColorMaski( GLuint buf, GLboolean red, GLboolean green,
829                         GLboolean blue, GLboolean alpha )
830 {
831    GLubyte tmp[4];
832    GET_CURRENT_CONTEXT(ctx);
833 
834    if (MESA_VERBOSE & VERBOSE_API)
835       _mesa_debug(ctx, "glColorMaskIndexed %u %d %d %d %d\n",
836                   buf, red, green, blue, alpha);
837 
838    if (buf >= ctx->Const.MaxDrawBuffers) {
839       _mesa_error(ctx, GL_INVALID_VALUE, "glColorMaskIndexed(buf=%u)", buf);
840       return;
841    }
842 
843    /* Shouldn't have any information about channel depth in core mesa
844     * -- should probably store these as the native booleans:
845     */
846    tmp[RCOMP] = red    ? 0xff : 0x0;
847    tmp[GCOMP] = green  ? 0xff : 0x0;
848    tmp[BCOMP] = blue   ? 0xff : 0x0;
849    tmp[ACOMP] = alpha  ? 0xff : 0x0;
850 
851    if (TEST_EQ_4V(tmp, ctx->Color.ColorMask[buf]))
852       return;
853 
854    FLUSH_VERTICES(ctx, _NEW_COLOR);
855    COPY_4UBV(ctx->Color.ColorMask[buf], tmp);
856 }
857 
858 
859 void GLAPIENTRY
_mesa_ClampColor(GLenum target,GLenum clamp)860 _mesa_ClampColor(GLenum target, GLenum clamp)
861 {
862    GET_CURRENT_CONTEXT(ctx);
863 
864    /* Check for both the extension and the GL version, since the Intel driver
865     * does not advertise the extension in core profiles.
866     */
867    if (ctx->Version <= 30 && !ctx->Extensions.ARB_color_buffer_float) {
868       _mesa_error(ctx, GL_INVALID_OPERATION, "glClampColor()");
869       return;
870    }
871 
872    if (clamp != GL_TRUE && clamp != GL_FALSE && clamp != GL_FIXED_ONLY_ARB) {
873       _mesa_error(ctx, GL_INVALID_ENUM, "glClampColorARB(clamp)");
874       return;
875    }
876 
877    switch (target) {
878    case GL_CLAMP_VERTEX_COLOR_ARB:
879       if (ctx->API == API_OPENGL_CORE)
880          goto invalid_enum;
881       FLUSH_VERTICES(ctx, _NEW_LIGHT);
882       ctx->Light.ClampVertexColor = clamp;
883       _mesa_update_clamp_vertex_color(ctx, ctx->DrawBuffer);
884       break;
885    case GL_CLAMP_FRAGMENT_COLOR_ARB:
886       if (ctx->API == API_OPENGL_CORE)
887          goto invalid_enum;
888       FLUSH_VERTICES(ctx, _NEW_FRAG_CLAMP);
889       ctx->Color.ClampFragmentColor = clamp;
890       _mesa_update_clamp_fragment_color(ctx, ctx->DrawBuffer);
891       break;
892    case GL_CLAMP_READ_COLOR_ARB:
893       ctx->Color.ClampReadColor = clamp;
894       break;
895    default:
896       goto invalid_enum;
897    }
898    return;
899 
900 invalid_enum:
901    _mesa_error(ctx, GL_INVALID_ENUM, "glClampColor(%s)",
902                _mesa_enum_to_string(target));
903 }
904 
905 static GLboolean
get_clamp_color(const struct gl_framebuffer * fb,GLenum clamp)906 get_clamp_color(const struct gl_framebuffer *fb, GLenum clamp)
907 {
908    if (clamp == GL_TRUE || clamp == GL_FALSE)
909       return clamp;
910 
911    assert(clamp == GL_FIXED_ONLY);
912    if (!fb)
913       return GL_TRUE;
914 
915    return fb->_AllColorBuffersFixedPoint;
916 }
917 
918 GLboolean
_mesa_get_clamp_fragment_color(const struct gl_context * ctx,const struct gl_framebuffer * drawFb)919 _mesa_get_clamp_fragment_color(const struct gl_context *ctx,
920                                const struct gl_framebuffer *drawFb)
921 {
922    return get_clamp_color(drawFb, ctx->Color.ClampFragmentColor);
923 }
924 
925 GLboolean
_mesa_get_clamp_vertex_color(const struct gl_context * ctx,const struct gl_framebuffer * drawFb)926 _mesa_get_clamp_vertex_color(const struct gl_context *ctx,
927                              const struct gl_framebuffer *drawFb)
928 {
929    return get_clamp_color(drawFb, ctx->Light.ClampVertexColor);
930 }
931 
932 GLboolean
_mesa_get_clamp_read_color(const struct gl_context * ctx,const struct gl_framebuffer * readFb)933 _mesa_get_clamp_read_color(const struct gl_context *ctx,
934                            const struct gl_framebuffer *readFb)
935 {
936    return get_clamp_color(readFb, ctx->Color.ClampReadColor);
937 }
938 
939 /**
940  * Update the ctx->Color._ClampFragmentColor field
941  */
942 void
_mesa_update_clamp_fragment_color(struct gl_context * ctx,const struct gl_framebuffer * drawFb)943 _mesa_update_clamp_fragment_color(struct gl_context *ctx,
944                                   const struct gl_framebuffer *drawFb)
945 {
946    /* Don't clamp if:
947     * - there is no colorbuffer
948     * - all colorbuffers are unsigned normalized, so clamping has no effect
949     * - there is an integer colorbuffer
950     */
951    if (!drawFb || !drawFb->_HasSNormOrFloatColorBuffer ||
952        drawFb->_IntegerBuffers)
953       ctx->Color._ClampFragmentColor = GL_FALSE;
954    else
955       ctx->Color._ClampFragmentColor =
956          _mesa_get_clamp_fragment_color(ctx, drawFb);
957 }
958 
959 /**
960  * Update the ctx->Color._ClampVertexColor field
961  */
962 void
_mesa_update_clamp_vertex_color(struct gl_context * ctx,const struct gl_framebuffer * drawFb)963 _mesa_update_clamp_vertex_color(struct gl_context *ctx,
964                                 const struct gl_framebuffer *drawFb)
965 {
966    ctx->Light._ClampVertexColor =
967          _mesa_get_clamp_vertex_color(ctx, drawFb);
968 }
969 
970 /**
971  * Returns an appropriate mesa_format for color rendering based on the
972  * GL_FRAMEBUFFER_SRGB state.
973  *
974  * Some drivers implement GL_FRAMEBUFFER_SRGB using a flag on the blend state
975  * (which GL_FRAMEBUFFER_SRGB maps to reasonably), but some have to do so by
976  * overriding the format of the surface.  This is a helper for doing the
977  * surface format override variant.
978  */
979 mesa_format
_mesa_get_render_format(const struct gl_context * ctx,mesa_format format)980 _mesa_get_render_format(const struct gl_context *ctx, mesa_format format)
981 {
982    if (ctx->Color.sRGBEnabled)
983       return format;
984    else
985       return _mesa_get_srgb_format_linear(format);
986 }
987 
988 /**********************************************************************/
989 /** \name Initialization */
990 /*@{*/
991 
992 /**
993  * Initialization of the context's Color attribute group.
994  *
995  * \param ctx GL context.
996  *
997  * Initializes the related fields in the context color attribute group,
998  * __struct gl_contextRec::Color.
999  */
_mesa_init_color(struct gl_context * ctx)1000 void _mesa_init_color( struct gl_context * ctx )
1001 {
1002    GLuint i;
1003 
1004    /* Color buffer group */
1005    ctx->Color.IndexMask = ~0u;
1006    memset(ctx->Color.ColorMask, 0xff, sizeof(ctx->Color.ColorMask));
1007    ctx->Color.ClearIndex = 0;
1008    ASSIGN_4V( ctx->Color.ClearColor.f, 0, 0, 0, 0 );
1009    ctx->Color.AlphaEnabled = GL_FALSE;
1010    ctx->Color.AlphaFunc = GL_ALWAYS;
1011    ctx->Color.AlphaRef = 0;
1012    ctx->Color.BlendEnabled = 0x0;
1013    for (i = 0; i < ARRAY_SIZE(ctx->Color.Blend); i++) {
1014       ctx->Color.Blend[i].SrcRGB = GL_ONE;
1015       ctx->Color.Blend[i].DstRGB = GL_ZERO;
1016       ctx->Color.Blend[i].SrcA = GL_ONE;
1017       ctx->Color.Blend[i].DstA = GL_ZERO;
1018       ctx->Color.Blend[i].EquationRGB = GL_FUNC_ADD;
1019       ctx->Color.Blend[i].EquationA = GL_FUNC_ADD;
1020    }
1021    ASSIGN_4V( ctx->Color.BlendColor, 0.0, 0.0, 0.0, 0.0 );
1022    ASSIGN_4V( ctx->Color.BlendColorUnclamped, 0.0, 0.0, 0.0, 0.0 );
1023    ctx->Color.IndexLogicOpEnabled = GL_FALSE;
1024    ctx->Color.ColorLogicOpEnabled = GL_FALSE;
1025    ctx->Color.LogicOp = GL_COPY;
1026    ctx->Color.DitherFlag = GL_TRUE;
1027 
1028    /* GL_FRONT is not possible on GLES. Instead GL_BACK will render to either
1029     * the front or the back buffer depending on the config */
1030    if (ctx->Visual.doubleBufferMode || _mesa_is_gles(ctx)) {
1031       ctx->Color.DrawBuffer[0] = GL_BACK;
1032    }
1033    else {
1034       ctx->Color.DrawBuffer[0] = GL_FRONT;
1035    }
1036 
1037    ctx->Color.ClampFragmentColor = ctx->API == API_OPENGL_COMPAT ?
1038                                    GL_FIXED_ONLY_ARB : GL_FALSE;
1039    ctx->Color._ClampFragmentColor = GL_FALSE;
1040    ctx->Color.ClampReadColor = GL_FIXED_ONLY_ARB;
1041 
1042    /* GLES 1/2/3 behaves as though GL_FRAMEBUFFER_SRGB is always enabled
1043     * if EGL_KHR_gl_colorspace has been used to request sRGB.
1044     */
1045    ctx->Color.sRGBEnabled = _mesa_is_gles(ctx);
1046 
1047    ctx->Color.BlendCoherent = true;
1048 }
1049 
1050 /*@}*/
1051