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 #ifndef GrGLSL_DEFINED 9 #define GrGLSL_DEFINED 10 11 #include "gl/GrGLInterface.h" 12 #include "GrColor.h" 13 #include "GrTypesPriv.h" 14 15 class GrGLShaderVar; 16 class SkString; 17 18 // Limited set of GLSL versions we build shaders for. Caller should round 19 // down the GLSL version to one of these enums. 20 enum GrGLSLGeneration { 21 /** 22 * Desktop GLSL 1.10 and ES2 shading language (based on desktop GLSL 1.20) 23 */ 24 k110_GrGLSLGeneration, 25 /** 26 * Desktop GLSL 1.30 27 */ 28 k130_GrGLSLGeneration, 29 /** 30 * Desktop GLSL 1.40 31 */ 32 k140_GrGLSLGeneration, 33 /** 34 * Desktop GLSL 1.50 35 */ 36 k150_GrGLSLGeneration, 37 }; 38 39 enum GrSLConstantVec { 40 kZeros_GrSLConstantVec, 41 kOnes_GrSLConstantVec, 42 kNone_GrSLConstantVec, 43 }; 44 45 namespace { 46 static inline int GrSLTypeToVecLength(GrSLType type) { 47 static const int kVecLengths[] = { 48 0, // kVoid_GrSLType 49 1, // kFloat_GrSLType 50 2, // kVec2f_GrSLType 51 3, // kVec3f_GrSLType 52 4, // kVec4f_GrSLType 53 1, // kMat33f_GrSLType 54 1, // kMat44f_GrSLType 55 1, // kSampler2D_GrSLType 56 }; 57 GR_STATIC_ASSERT(kGrSLTypeCount == GR_ARRAY_COUNT(kVecLengths)); 58 return kVecLengths[type]; 59 } 60 61 static inline const char* GrGLSLOnesVecf(int count) { 62 static const char* kONESVEC[] = {"ERROR", "1.0", "vec2(1,1)", 63 "vec3(1,1,1)", "vec4(1,1,1,1)"}; 64 GrAssert(count >= 1 && count < (int)GR_ARRAY_COUNT(kONESVEC)); 65 return kONESVEC[count]; 66 } 67 68 static inline const char* GrGLSLZerosVecf(int count) { 69 static const char* kZEROSVEC[] = {"ERROR", "0.0", "vec2(0,0)", 70 "vec3(0,0,0)", "vec4(0,0,0,0)"}; 71 GrAssert(count >= 1 && count < (int)GR_ARRAY_COUNT(kZEROSVEC)); 72 return kZEROSVEC[count]; 73 } 74 } 75 76 /** 77 * Gets the most recent GLSL Generation compatible with the OpenGL context. 78 */ 79 GrGLSLGeneration GrGetGLSLGeneration(GrGLBinding binding, 80 const GrGLInterface* gl); 81 82 /** 83 * Returns a string to include at the beginning of a shader to declare the GLSL 84 * version. 85 */ 86 const char* GrGetGLSLVersionDecl(GrGLBinding binding, 87 GrGLSLGeneration v); 88 89 /** 90 * Depending on the GLSL version being emitted there may be an assumed output 91 * variable from the fragment shader for the color. Otherwise, the shader must 92 * declare an output variable for the color. If this function returns true: 93 * * Parameter var's name will be set to nameIfDeclared 94 * * The variable must be declared in the fragment shader 95 * * The variable has to be bound as the color output 96 * (using glBindFragDataLocation) 97 * If the function returns false: 98 * * Parameter var's name will be set to the GLSL built-in color output name. 99 * * Do not declare the variable in the shader. 100 * * Do not use glBindFragDataLocation to bind the variable 101 * In either case var is initialized to represent the color output in the 102 * shader. 103 */ 104 bool GrGLSLSetupFSColorOuput(GrGLSLGeneration gen, 105 const char* nameIfDeclared, 106 GrGLShaderVar* var); 107 /** 108 * Converts a GrSLType to a string containing the name of the equivalent GLSL type. 109 */ 110 static const char* GrGLSLTypeString(GrSLType t) { 111 switch (t) { 112 case kVoid_GrSLType: 113 return "void"; 114 case kFloat_GrSLType: 115 return "float"; 116 case kVec2f_GrSLType: 117 return "vec2"; 118 case kVec3f_GrSLType: 119 return "vec3"; 120 case kVec4f_GrSLType: 121 return "vec4"; 122 case kMat33f_GrSLType: 123 return "mat3"; 124 case kMat44f_GrSLType: 125 return "mat4"; 126 case kSampler2D_GrSLType: 127 return "sampler2D"; 128 default: 129 GrCrash("Unknown shader var type."); 130 return ""; // suppress warning 131 } 132 } 133 134 /** Return the type enum for a vector of floats of length n (1..4), 135 e.g. 1 -> "float", 2 -> "vec2", ... */ 136 static inline const char* GrGLSLFloatVectorTypeString(int n) { 137 return GrGLSLTypeString(GrSLFloatVectorType(n)); 138 } 139 140 /** Return the GLSL swizzle operator for a homogenous component of a vector 141 with the given number of coordinates, e.g. 2 -> ".y", 3 -> ".z" */ 142 const char* GrGLSLVectorHomogCoord(int count); 143 const char* GrGLSLVectorHomogCoord(GrSLType type); 144 145 /** Return the GLSL swizzle operator for a nonhomogenous components of a vector 146 with the given number of coordinates, e.g. 2 -> ".x", 3 -> ".xy" */ 147 const char* GrGLSLVectorNonhomogCoords(int count); 148 const char* GrGLSLVectorNonhomogCoords(GrSLType type); 149 150 /** 151 * Produces a string that is the result of modulating two inputs. The inputs must be vecN or 152 * float. The result is always a vecN. The inputs may be expressions, not just identifier names. 153 * Either can be NULL or "" in which case the default params control whether a vector of ones or 154 * zeros. It is an error to pass kNone for default<i> if in<i> is NULL or "". Note that when the 155 * function determines that the result is a zeros or ones vec then any expression represented by 156 * or in1 will not be emitted (side effects won't occur). The return value indicates whether a 157 * known zeros or ones vector resulted. The output can be suppressed when known vector is produced 158 * by passing true for omitIfConstVec. 159 */ 160 template <int N> 161 GrSLConstantVec GrGLSLModulatef(SkString* outAppend, 162 const char* in0, 163 const char* in1, 164 GrSLConstantVec default0 = kOnes_GrSLConstantVec, 165 GrSLConstantVec default1 = kOnes_GrSLConstantVec, 166 bool omitIfConstVec = false); 167 168 /** 169 * Produces a string that is the result of adding two inputs. The inputs must be vecN or 170 * float. The result is always a vecN. The inputs may be expressions, not just identifier names. 171 * Either can be NULL or "" in which case the default params control whether a vector of ones or 172 * zeros. It is an error to pass kNone for default<i> if in<i> is NULL or "". Note that when the 173 * function determines that the result is a zeros or ones vec then any expression represented by 174 * or in1 will not be emitted (side effects won't occur). The return value indicates whether a 175 * known zeros or ones vector resulted. The output can be suppressed when known vector is produced 176 * by passing true for omitIfConstVec. 177 */ 178 template <int N> 179 GrSLConstantVec GrGLSLAddf(SkString* outAppend, 180 const char* in0, 181 const char* in1, 182 GrSLConstantVec default0 = kZeros_GrSLConstantVec, 183 GrSLConstantVec default1 = kZeros_GrSLConstantVec, 184 bool omitIfConstVec = false); 185 186 /** 187 * Produces a string that is the result of subtracting two inputs. The inputs must be vecN or 188 * float. The result is always a vecN. The inputs may be expressions, not just identifier names. 189 * Either can be NULL or "" in which case the default params control whether a vector of ones or 190 * zeros. It is an error to pass kNone for default<i> if in<i> is NULL or "". Note that when the 191 * function determines that the result is a zeros or ones vec then any expression represented by 192 * or in1 will not be emitted (side effects won't occur). The return value indicates whether a 193 * known zeros or ones vector resulted. The output can be suppressed when known vector is produced 194 * by passing true for omitIfConstVec. 195 */ 196 template <int N> 197 GrSLConstantVec GrGLSLSubtractf(SkString* outAppend, 198 const char* in0, 199 const char* in1, 200 GrSLConstantVec default0 = kZeros_GrSLConstantVec, 201 GrSLConstantVec default1 = kZeros_GrSLConstantVec, 202 bool omitIfConstVec = false); 203 204 /** 205 * Does an inplace mul, *=, of vec4VarName by mulFactor. If mulFactorDefault is not kNone then 206 * mulFactor may be either "" or NULL. In this case either nothing will be appended (kOnes) or an 207 * assignment of vec(0,0,0,0) will be appended (kZeros). The assignment is prepended by tabCnt tabs. 208 * A semicolon and newline are added after the assignment. (TODO: Remove tabCnt when we auto-insert 209 * tabs to GrGLEffect-generated lines.) If a zeros vec is assigned then the return value is 210 * kZeros, otherwise kNone. 211 */ 212 GrSLConstantVec GrGLSLMulVarBy4f(SkString* outAppend, 213 int tabCnt, 214 const char* vec4VarName, 215 const char* mulFactor, 216 GrSLConstantVec mulFactorDefault = kOnes_GrSLConstantVec); 217 218 /** 219 * Given an expression that evaluates to a GLSL vec4, extract a component. If expr is NULL or "" 220 * the value of defaultExpr is used. It is an error to pass an empty expr and have set defaultExpr 221 * to kNone. The return value indicates whether the value is known to be 0 or 1. If omitIfConst is 222 * set then nothing is appended when the return is not kNone. 223 */ 224 GrSLConstantVec GrGLSLGetComponent4f(SkString* outAppend, 225 const char* expr, 226 GrColorComponentFlags component, 227 GrSLConstantVec defaultExpr = kNone_GrSLConstantVec, 228 bool omitIfConst = false); 229 230 #include "GrGLSL_impl.h" 231 232 #endif 233
