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      1 /*
      2  * Copyright 2011 Google Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #include "GrGLSL.h"
      9 #include "GrGLShaderVar.h"
     10 #include "SkString.h"
     11 
     12 bool GrGetGLSLGeneration(const GrGLInterface* gl, GrGLSLGeneration* generation) {
     13     SkASSERT(NULL != generation);
     14     GrGLSLVersion ver = GrGLGetGLSLVersion(gl);
     15     if (GR_GLSL_INVALID_VER == ver) {
     16         return false;
     17     }
     18     switch (gl->fStandard) {
     19         case kGL_GrGLStandard:
     20             SkASSERT(ver >= GR_GLSL_VER(1,10));
     21             if (ver >= GR_GLSL_VER(1,50)) {
     22                 *generation = k150_GrGLSLGeneration;
     23             } else if (ver >= GR_GLSL_VER(1,40)) {
     24                 *generation = k140_GrGLSLGeneration;
     25             } else if (ver >= GR_GLSL_VER(1,30)) {
     26                 *generation = k130_GrGLSLGeneration;
     27             } else {
     28                 *generation = k110_GrGLSLGeneration;
     29             }
     30             return true;
     31         case kGLES_GrGLStandard:
     32             // version 1.00 of ES GLSL based on ver 1.20 of desktop GLSL
     33             SkASSERT(ver >= GR_GL_VER(1,00));
     34             *generation = k110_GrGLSLGeneration;
     35             return true;
     36         default:
     37             SkFAIL("Unknown GL Standard");
     38             return false;
     39     }
     40 }
     41 
     42 const char* GrGetGLSLVersionDecl(const GrGLContextInfo& info) {
     43     switch (info.glslGeneration()) {
     44         case k110_GrGLSLGeneration:
     45             if (kGLES_GrGLStandard == info.standard()) {
     46                 // ES2s shader language is based on version 1.20 but is version
     47                 // 1.00 of the ES language.
     48                 return "#version 100\n";
     49             } else {
     50                 SkASSERT(kGL_GrGLStandard == info.standard());
     51                 return "#version 110\n";
     52             }
     53         case k130_GrGLSLGeneration:
     54             SkASSERT(kGL_GrGLStandard == info.standard());
     55             return "#version 130\n";
     56         case k140_GrGLSLGeneration:
     57             SkASSERT(kGL_GrGLStandard == info.standard());
     58             return "#version 140\n";
     59         case k150_GrGLSLGeneration:
     60             SkASSERT(kGL_GrGLStandard == info.standard());
     61             if (info.caps()->isCoreProfile()) {
     62                 return "#version 150\n";
     63             } else {
     64                 return "#version 150 compatibility\n";
     65             }
     66         default:
     67             SkFAIL("Unknown GL version.");
     68             return ""; // suppress warning
     69     }
     70 }
     71 
     72 namespace {
     73     void append_tabs(SkString* outAppend, int tabCnt) {
     74         static const char kTabs[] = "\t\t\t\t\t\t\t\t";
     75         while (tabCnt) {
     76             int cnt = SkTMin((int)SK_ARRAY_COUNT(kTabs), tabCnt);
     77             outAppend->append(kTabs, cnt);
     78             tabCnt -= cnt;
     79         }
     80     }
     81 }
     82 
     83 void GrGLSLMulVarBy4f(SkString* outAppend,
     84                       unsigned tabCnt,
     85                       const char* vec4VarName,
     86                       const GrGLSLExpr4& mulFactor) {
     87     if (mulFactor.isOnes()) {
     88         *outAppend = SkString();
     89     }
     90 
     91     append_tabs(outAppend, tabCnt);
     92 
     93     if (mulFactor.isZeros()) {
     94         outAppend->appendf("%s = vec4(0);\n", vec4VarName);
     95     } else {
     96         outAppend->appendf("%s *= %s;\n", vec4VarName, mulFactor.c_str());
     97     }
     98 }
     99