Check for divide by zero in fill_in_1D_gaussian_kernel

Bug: skia:7769
Change-Id: I56a67f8a6f19437359ad6e7bf2d57f6e9a7992c9
Reviewed-on: https://skia-review.googlesource.com/118240
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/src/gpu/effects/GrGaussianConvolutionFragmentProcessor.cpp b/src/gpu/effects/GrGaussianConvolutionFragmentProcessor.cpp
index 5fae103498..121e225796 100644
--- a/src/gpu/effects/GrGaussianConvolutionFragmentProcessor.cpp
+++ b/src/gpu/effects/GrGaussianConvolutionFragmentProcessor.cpp
@@ -177,7 +177,15 @@ void GrGLConvolutionEffect::GenKey(const GrProcessor& processor, const GrShaderC
 
 ///////////////////////////////////////////////////////////////////////////////
 static void fill_in_1D_gaussian_kernel(float* kernel, int width, float gaussianSigma, int radius) {
-    const float denom = 1.0f / (2.0f * gaussianSigma * gaussianSigma);
+    float twoSigmaSqrd = 2.0f * gaussianSigma * gaussianSigma;
+    if (SkScalarNearlyZero(twoSigmaSqrd, SK_ScalarNearlyZero)) {
+        for (int i = 0; i < width; ++i) {
+            kernel[i] = 0.0f;
+        }
+        return;
+    }
+
+    const float denom = 1.0f / twoSigmaSqrd;
 
     float sum = 0.0f;
     for (int i = 0; i < width; ++i) {