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1 /* |
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2 * Copyright 2012 Google Inc. |
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3 * |
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4 * Use of this source code is governed by a BSD-style license that can be |
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5 * found in the LICENSE file. |
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6 */ |
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7 |
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8 #ifndef SkGradientShaderPriv_DEFINED |
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9 #define SkGradientShaderPriv_DEFINED |
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10 |
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11 #include "SkGradientShader.h" |
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12 #include "SkClampRange.h" |
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13 #include "SkColorPriv.h" |
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14 #include "SkReadBuffer.h" |
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15 #include "SkWriteBuffer.h" |
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16 #include "SkMallocPixelRef.h" |
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17 #include "SkUnitMapper.h" |
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18 #include "SkUtils.h" |
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19 #include "SkTemplates.h" |
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20 #include "SkBitmapCache.h" |
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21 #include "SkShader.h" |
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22 |
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23 static inline void sk_memset32_dither(uint32_t dst[], uint32_t v0, uint32_t v1, |
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24 int count) { |
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25 if (count > 0) { |
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26 if (v0 == v1) { |
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27 sk_memset32(dst, v0, count); |
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28 } else { |
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29 int pairs = count >> 1; |
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30 for (int i = 0; i < pairs; i++) { |
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31 *dst++ = v0; |
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32 *dst++ = v1; |
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33 } |
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34 if (count & 1) { |
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35 *dst = v0; |
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36 } |
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37 } |
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38 } |
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39 } |
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40 |
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41 // Clamp |
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42 |
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43 static inline SkFixed clamp_tileproc(SkFixed x) { |
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44 return SkClampMax(x, 0xFFFF); |
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45 } |
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46 |
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47 // Repeat |
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48 |
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49 static inline SkFixed repeat_tileproc(SkFixed x) { |
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50 return x & 0xFFFF; |
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51 } |
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52 |
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53 // Mirror |
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54 |
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55 // Visual Studio 2010 (MSC_VER=1600) optimizes bit-shift code incorrectly. |
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56 // See http://code.google.com/p/skia/issues/detail?id=472 |
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57 #if defined(_MSC_VER) && (_MSC_VER >= 1600) |
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58 #pragma optimize("", off) |
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59 #endif |
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60 |
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61 static inline SkFixed mirror_tileproc(SkFixed x) { |
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62 int s = x << 15 >> 31; |
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63 return (x ^ s) & 0xFFFF; |
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64 } |
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65 |
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66 #if defined(_MSC_VER) && (_MSC_VER >= 1600) |
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67 #pragma optimize("", on) |
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68 #endif |
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69 |
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70 /////////////////////////////////////////////////////////////////////////////// |
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71 |
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72 typedef SkFixed (*TileProc)(SkFixed); |
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73 |
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74 /////////////////////////////////////////////////////////////////////////////// |
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75 |
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76 static const TileProc gTileProcs[] = { |
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77 clamp_tileproc, |
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78 repeat_tileproc, |
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79 mirror_tileproc |
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80 }; |
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81 |
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82 /////////////////////////////////////////////////////////////////////////////// |
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83 |
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84 class SkGradientShaderBase : public SkShader { |
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85 public: |
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86 struct Descriptor { |
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87 Descriptor() { |
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88 sk_bzero(this, sizeof(*this)); |
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89 fTileMode = SkShader::kClamp_TileMode; |
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90 } |
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91 |
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92 const SkColor* fColors; |
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93 const SkScalar* fPos; |
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94 int fCount; |
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95 SkShader::TileMode fTileMode; |
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96 SkUnitMapper* fMapper; |
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97 uint32_t fFlags; |
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98 }; |
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99 |
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100 public: |
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101 SkGradientShaderBase(const Descriptor& desc); |
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102 virtual ~SkGradientShaderBase(); |
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103 |
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104 virtual bool setContext(const SkBitmap&, const SkPaint&, const SkMatrix&) SK_OVERRIDE; |
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105 virtual uint32_t getFlags() SK_OVERRIDE { return fFlags; } |
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106 virtual bool isOpaque() const SK_OVERRIDE; |
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107 |
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108 void getGradientTableBitmap(SkBitmap*) const; |
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109 |
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110 enum { |
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111 /// Seems like enough for visual accuracy. TODO: if pos[] deserves |
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112 /// it, use a larger cache. |
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113 kCache16Bits = 8, |
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114 kCache16Count = (1 << kCache16Bits), |
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115 kCache16Shift = 16 - kCache16Bits, |
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116 kSqrt16Shift = 8 - kCache16Bits, |
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117 |
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118 /// Seems like enough for visual accuracy. TODO: if pos[] deserves |
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119 /// it, use a larger cache. |
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120 kCache32Bits = 8, |
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121 kCache32Count = (1 << kCache32Bits), |
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122 kCache32Shift = 16 - kCache32Bits, |
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123 kSqrt32Shift = 8 - kCache32Bits, |
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124 |
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125 /// This value is used to *read* the dither cache; it may be 0 |
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126 /// if dithering is disabled. |
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127 kDitherStride32 = kCache32Count, |
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128 kDitherStride16 = kCache16Count, |
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129 }; |
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130 |
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131 |
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132 protected: |
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133 SkGradientShaderBase(SkReadBuffer& ); |
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134 virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE; |
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135 SK_TO_STRING_OVERRIDE() |
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136 |
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137 SkUnitMapper* fMapper; |
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138 SkMatrix fPtsToUnit; // set by subclass |
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139 SkMatrix fDstToIndex; |
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140 SkMatrix::MapXYProc fDstToIndexProc; |
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141 TileMode fTileMode; |
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142 TileProc fTileProc; |
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143 int fColorCount; |
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144 uint8_t fDstToIndexClass; |
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145 uint8_t fFlags; |
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146 uint8_t fGradFlags; |
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147 |
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148 struct Rec { |
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149 SkFixed fPos; // 0...1 |
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150 uint32_t fScale; // (1 << 24) / range |
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151 }; |
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152 Rec* fRecs; |
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153 |
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154 const uint16_t* getCache16() const; |
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155 const SkPMColor* getCache32() const; |
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156 |
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157 void commonAsAGradient(GradientInfo*) const; |
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158 |
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159 private: |
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160 enum { |
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161 kColorStorageCount = 4, // more than this many colors, and we'll use sk_malloc for the space |
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162 |
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163 kStorageSize = kColorStorageCount * (sizeof(SkColor) + sizeof(Rec)) |
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164 }; |
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165 SkColor fStorage[(kStorageSize + 3) >> 2]; |
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166 SkColor* fOrigColors; // original colors, before modulation by paint in setContext |
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167 bool fColorsAreOpaque; |
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168 |
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169 mutable uint16_t* fCache16; // working ptr. If this is NULL, we need to recompute the cache values |
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170 mutable SkPMColor* fCache32; // working ptr. If this is NULL, we need to recompute the cache values |
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171 |
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172 mutable uint16_t* fCache16Storage; // storage for fCache16, allocated on demand |
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173 mutable SkMallocPixelRef* fCache32PixelRef; |
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174 mutable unsigned fCacheAlpha; // the alpha value we used when we computed the cache. larger than 8bits so we can store uninitialized value |
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175 |
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176 static void Build16bitCache(uint16_t[], SkColor c0, SkColor c1, int count); |
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177 static void Build32bitCache(SkPMColor[], SkColor c0, SkColor c1, int count, |
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178 U8CPU alpha, uint32_t gradFlags); |
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179 void setCacheAlpha(U8CPU alpha) const; |
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180 void initCommon(); |
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181 |
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182 typedef SkShader INHERITED; |
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183 }; |
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184 |
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185 static inline int init_dither_toggle(int x, int y) { |
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186 x &= 1; |
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187 y = (y & 1) << 1; |
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188 return (x | y) * SkGradientShaderBase::kDitherStride32; |
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189 } |
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190 |
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191 static inline int next_dither_toggle(int toggle) { |
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192 return toggle ^ SkGradientShaderBase::kDitherStride32; |
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193 } |
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194 |
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195 static inline int init_dither_toggle16(int x, int y) { |
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196 return ((x ^ y) & 1) * SkGradientShaderBase::kDitherStride16; |
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197 } |
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198 |
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199 static inline int next_dither_toggle16(int toggle) { |
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200 return toggle ^ SkGradientShaderBase::kDitherStride16; |
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201 } |
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202 |
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203 /////////////////////////////////////////////////////////////////////////////// |
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204 |
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205 #if SK_SUPPORT_GPU |
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206 |
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207 #include "GrCoordTransform.h" |
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208 #include "gl/GrGLEffect.h" |
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209 |
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210 class GrEffectStage; |
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211 class GrBackendEffectFactory; |
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212 |
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213 /* |
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214 * The interpretation of the texture matrix depends on the sample mode. The |
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215 * texture matrix is applied both when the texture coordinates are explicit |
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216 * and when vertex positions are used as texture coordinates. In the latter |
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217 * case the texture matrix is applied to the pre-view-matrix position |
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218 * values. |
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219 * |
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220 * Normal SampleMode |
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221 * The post-matrix texture coordinates are in normalize space with (0,0) at |
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222 * the top-left and (1,1) at the bottom right. |
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223 * RadialGradient |
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224 * The matrix specifies the radial gradient parameters. |
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225 * (0,0) in the post-matrix space is center of the radial gradient. |
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226 * Radial2Gradient |
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227 * Matrix transforms to space where first circle is centered at the |
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228 * origin. The second circle will be centered (x, 0) where x may be |
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229 * 0 and is provided by setRadial2Params. The post-matrix space is |
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230 * normalized such that 1 is the second radius - first radius. |
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231 * SweepGradient |
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232 * The angle from the origin of texture coordinates in post-matrix space |
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233 * determines the gradient value. |
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234 */ |
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235 |
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236 class GrTextureStripAtlas; |
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237 |
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238 // Base class for Gr gradient effects |
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239 class GrGradientEffect : public GrEffect { |
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240 public: |
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241 |
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242 GrGradientEffect(GrContext* ctx, |
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243 const SkGradientShaderBase& shader, |
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244 const SkMatrix& matrix, |
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245 SkShader::TileMode tileMode); |
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246 |
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247 virtual ~GrGradientEffect(); |
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248 |
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249 bool useAtlas() const { return SkToBool(-1 != fRow); } |
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250 SkScalar getYCoord() const { return fYCoord; }; |
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251 |
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252 virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE; |
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253 |
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254 enum ColorType { |
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255 kTwo_ColorType, |
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256 kThree_ColorType, |
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257 kTexture_ColorType |
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258 }; |
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259 |
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260 ColorType getColorType() const { return fColorType; } |
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261 |
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262 enum PremulType { |
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263 kBeforeInterp_PremulType, |
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264 kAfterInterp_PremulType, |
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265 }; |
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266 |
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267 PremulType getPremulType() const { return fPremulType; } |
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268 |
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269 const SkColor* getColors(int pos) const { |
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270 SkASSERT(fColorType != kTexture_ColorType); |
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271 SkASSERT((pos-1) <= fColorType); |
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272 return &fColors[pos]; |
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273 } |
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274 |
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275 protected: |
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276 |
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277 /** Populates a pair of arrays with colors and stop info to construct a random gradient. |
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278 The function decides whether stop values should be used or not. The return value indicates |
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279 the number of colors, which will be capped by kMaxRandomGradientColors. colors should be |
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280 sized to be at least kMaxRandomGradientColors. stops is a pointer to an array of at least |
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281 size kMaxRandomGradientColors. It may be updated to NULL, indicating that NULL should be |
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282 passed to the gradient factory rather than the array. |
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283 */ |
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284 static const int kMaxRandomGradientColors = 4; |
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285 static int RandomGradientParams(SkRandom* r, |
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286 SkColor colors[kMaxRandomGradientColors], |
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287 SkScalar** stops, |
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288 SkShader::TileMode* tm); |
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289 |
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290 virtual bool onIsEqual(const GrEffect& effect) const SK_OVERRIDE; |
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291 |
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292 const GrCoordTransform& getCoordTransform() const { return fCoordTransform; } |
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293 |
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294 private: |
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295 static const GrCoordSet kCoordSet = kLocal_GrCoordSet; |
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296 |
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297 enum { |
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298 kMaxAnalyticColors = 3 // if more colors use texture |
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299 }; |
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300 |
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301 GrCoordTransform fCoordTransform; |
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302 GrTextureAccess fTextureAccess; |
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303 SkScalar fYCoord; |
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304 GrTextureStripAtlas* fAtlas; |
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305 int fRow; |
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306 bool fIsOpaque; |
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307 ColorType fColorType; |
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308 SkColor fColors[kMaxAnalyticColors]; |
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309 PremulType fPremulType; // This only changes behavior for two and three color special cases. |
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310 // It is already baked into to the table for texture gradients. |
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311 typedef GrEffect INHERITED; |
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312 |
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313 }; |
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314 |
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315 /////////////////////////////////////////////////////////////////////////////// |
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316 |
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317 // Base class for GL gradient effects |
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318 class GrGLGradientEffect : public GrGLEffect { |
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319 public: |
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320 GrGLGradientEffect(const GrBackendEffectFactory& factory); |
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321 virtual ~GrGLGradientEffect(); |
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322 |
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323 virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE; |
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324 |
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325 protected: |
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326 enum { |
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327 kPremulTypeKeyBitCnt = 1, |
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328 kPremulTypeMask = 1, |
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329 kPremulBeforeInterpKey = kPremulTypeMask, |
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330 |
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331 kTwoColorKey = 2 << kPremulTypeKeyBitCnt, |
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332 kThreeColorKey = 3 << kPremulTypeKeyBitCnt, |
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333 kColorKeyMask = kTwoColorKey | kThreeColorKey, |
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334 kColorKeyBitCnt = 2, |
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335 |
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336 // Subclasses must shift any key bits they produce up by this amount |
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337 // and combine with the result of GenBaseGradientKey. |
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338 kBaseKeyBitCnt = (kPremulTypeKeyBitCnt + kColorKeyBitCnt) |
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339 }; |
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340 |
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341 static GrGradientEffect::ColorType ColorTypeFromKey(EffectKey key){ |
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342 if (kTwoColorKey == (key & kColorKeyMask)) { |
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343 return GrGradientEffect::kTwo_ColorType; |
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344 } else if (kThreeColorKey == (key & kColorKeyMask)) { |
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345 return GrGradientEffect::kThree_ColorType; |
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346 } else {return GrGradientEffect::kTexture_ColorType;} |
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347 } |
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348 |
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349 static GrGradientEffect::PremulType PremulTypeFromKey(EffectKey key){ |
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350 if (kPremulBeforeInterpKey == (key & kPremulTypeMask)) { |
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351 return GrGradientEffect::kBeforeInterp_PremulType; |
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352 } else { |
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353 return GrGradientEffect::kAfterInterp_PremulType; |
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354 } |
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355 } |
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356 |
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357 /** |
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358 * Subclasses must call this. It will return a value restricted to the lower kBaseKeyBitCnt |
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359 * bits. |
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360 */ |
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361 static EffectKey GenBaseGradientKey(const GrDrawEffect&); |
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362 |
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363 // Emits the uniform used as the y-coord to texture samples in derived classes. Subclasses |
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364 // should call this method from their emitCode(). |
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365 void emitUniforms(GrGLShaderBuilder* builder, EffectKey key); |
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366 |
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367 |
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368 // emit code that gets a fragment's color from an expression for t; Has branches for 3 separate |
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369 // control flows inside -- 2 color gradients, 3 color symmetric gradients (both using |
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370 // native GLSL mix), and 4+ color gradients that use the traditional texture lookup. |
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371 void emitColor(GrGLShaderBuilder* builder, |
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372 const char* gradientTValue, |
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373 EffectKey key, |
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374 const char* outputColor, |
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375 const char* inputColor, |
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376 const TextureSamplerArray& samplers); |
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377 |
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378 private: |
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379 SkScalar fCachedYCoord; |
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380 GrGLUniformManager::UniformHandle fFSYUni; |
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381 GrGLUniformManager::UniformHandle fColorStartUni; |
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382 GrGLUniformManager::UniformHandle fColorMidUni; |
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383 GrGLUniformManager::UniformHandle fColorEndUni; |
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384 |
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385 typedef GrGLEffect INHERITED; |
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386 }; |
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387 |
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388 #endif |
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389 |
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390 #endif |