commit 1d4f5775ee060ce5c7471261dbf701b36b3180af
author Nicolas Capens <capn@google.com> Wed Jul 03 23:57:28 2019 -0400
committer Nicolas Capens <nicolascapens@google.com> Thu Jul 04 18:51:27 2019 +0000
tree fcd7e0f5110dfdd410dad59445b5309af81d4732
parent 49f8051e927f72ce6ad884eb99cb0f0e536c8b79

Clamp GLSL textureSize() lod to mipmap range

Bug chromium:980816

Change-Id: Ic4393668f82316e475baa5e753d891dfb1e30572
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/33728
Presubmit-Ready: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>

src/Shader/SamplerCore.cpp

diff --git a/src/Shader/SamplerCore.cpp b/src/Shader/SamplerCore.cpp
index 6b8290d..5f9888c 100644
--- a/src/Shader/SamplerCore.cpp
+++ b/src/Shader/SamplerCore.cpp
@@ -506,7 +506,8 @@
 		for(int i = 0; i < 4; ++i)
 		{
 			Int baseLevel = *Pointer<Int>(texture + OFFSET(Texture, baseLevel));
-			Pointer<Byte> mipmap = texture + OFFSET(Texture, mipmap) + (As<Int>(Extract(lod, i)) + baseLevel) * sizeof(Mipmap);
+			Int index = Min(As<UInt>(As<Int>(Extract(lod, i)) + baseLevel), MIPMAP_LEVELS - 1);
+			Pointer<Byte> mipmap = texture + OFFSET(Texture, mipmap) + index * sizeof(Mipmap);
 			size.x = Insert(size.x, As<Float>(Int(*Pointer<Short>(mipmap + OFFSET(Mipmap, width)))), i);
 			size.y = Insert(size.y, As<Float>(Int(*Pointer<Short>(mipmap + OFFSET(Mipmap, height)))), i);
 			size.z = Insert(size.z, As<Float>(Int(*Pointer<Short>(mipmap + OFFSET(Mipmap, depth)))), i);