pdf: ifgnore shader colors applied for 0 range.

src/pdf/SkPDFShader.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkPDFShader.h"
@@ skipping 37 matching lines @@
    between startOffset and endOffset from prevColor to curColor (for each color
    component), leaving the result in component order on the stack. It assumes
    there are always 3 components per color.
    @param range                  endOffset - startOffset
    @param curColor[components]   The current color components.
    @param prevColor[components]  The previous color components.
    @param result                 The result ps function.
  */
 static void interpolateColorCode(SkScalar range, SkScalar* curColor,
                                  SkScalar* prevColor, SkString* result) {
+    SkASSERT(range != SkIntToScalar(0));
     static const int kColorComponents = 3;
 
     // Figure out how to scale each color component.
     SkScalar multiplier[kColorComponents];
     for (int i = 0; i < kColorComponents; i++) {
         multiplier[i] = SkScalarDiv(curColor[i] - prevColor[i], range);
     }
 
     // Calculate when we no longer need to keep a copy of the input parameter t.
     // If the last component to use t is i, then dupInput[0..i - 1] = true
@@ skipping 77 matching lines @@
     // Clamp the initial color.
     result->append("dup 0 le {pop ");
     result->appendScalar(colorData[0][0]);
     result->append(" ");
     result->appendScalar(colorData[0][1]);
     result->append(" ");
     result->appendScalar(colorData[0][2]);
     result->append(" }\n");
 
     // The gradient colors.
+    int gradients = 0;
     for (int i = 1 ; i < info.fColorCount; i++) {
+        if (info.fColorOffsets[i] == info.fColorOffsets[i - 1]) {
+            continue;
+        }
+        gradients++;
+
         result->append("{dup ");
         result->appendScalar(info.fColorOffsets[i]);
         result->append(" le {");
         if (info.fColorOffsets[i - 1] != 0) {
             result->appendScalar(info.fColorOffsets[i - 1]);
             result->append(" sub\n");
         }
 
         interpolateColorCode(info.fColorOffsets[i] - info.fColorOffsets[i - 1],
                              colorData[i], colorData[i - 1], result);
         result->append("}\n");
     }
 
     // Clamp the final color.
     result->append("{pop ");
     result->appendScalar(colorData[info.fColorCount - 1][0]);
     result->append(" ");
     result->appendScalar(colorData[info.fColorCount - 1][1]);
     result->append(" ");
     result->appendScalar(colorData[info.fColorCount - 1][2]);
 
-    for (int i = 0 ; i < info.fColorCount; i++) {
+    for (int i = 0 ; i < gradients + 1; i++) {
         result->append("} ifelse\n");
     }
 }
 
 /* Map a value of t on the stack into [0, 1) for Repeat or Mirror tile mode. */
 static void tileModeCode(SkShader::TileMode mode, SkString* result) {
     if (mode == SkShader::kRepeat_TileMode) {
         result->append("dup truncate sub\n");  // Get the fractional part.
         result->append("dup 0 le {1 add} if\n");  // Map (-1,0) => (0,1)
         return;
@@ skipping 1022 matching lines @@
     return false;
 }
 
 void SkPDFShader::State::AllocateGradientInfoStorage() {
     fColorData.set(sk_malloc_throw(
                fInfo.fColorCount * (sizeof(SkColor) + sizeof(SkScalar))));
     fInfo.fColors = reinterpret_cast<SkColor*>(fColorData.get());
     fInfo.fColorOffsets =
             reinterpret_cast<SkScalar*>(fInfo.fColors + fInfo.fColorCount);
 }