Validate invariance of built-in variables when linking
According to ESSL 1.00.17 paragraph 4.6.4
BUG=angleproject:1876
Change-Id: I61e142c31dce11eec28fe240a9bc9ce2c632daf6
Reviewed-on: https://chromium-review.googlesource.com/446870
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>
diff --git a/src/libANGLE/Program.cpp b/src/libANGLE/Program.cpp
index 2cf4307..52c2dfa 100644
--- a/src/libANGLE/Program.cpp
+++ b/src/libANGLE/Program.cpp
@@ -1917,6 +1917,11 @@
}
}
+ if (!linkValidateBuiltInVaryings(infoLog))
+ {
+ return false;
+ }
+
// TODO(jmadill): verify no unmatched vertex varyings?
return true;
@@ -2445,6 +2450,77 @@
return true;
}
+bool Program::linkValidateBuiltInVaryings(InfoLog &infoLog) const
+{
+ const Shader *vertexShader = mState.mAttachedVertexShader;
+ const Shader *fragmentShader = mState.mAttachedFragmentShader;
+ const std::vector<sh::Varying> &vertexVaryings = vertexShader->getVaryings();
+ const std::vector<sh::Varying> &fragmentVaryings = fragmentShader->getVaryings();
+ int shaderVersion = vertexShader->getShaderVersion();
+
+ if (shaderVersion != 100)
+ {
+ // Only ESSL 1.0 has restrictions on matching input and output invariance
+ return true;
+ }
+
+ bool glPositionIsInvariant = false;
+ bool glPointSizeIsInvariant = false;
+ bool glFragCoordIsInvariant = false;
+ bool glPointCoordIsInvariant = false;
+
+ for (const sh::Varying &varying : vertexVaryings)
+ {
+ if (!varying.isBuiltIn())
+ {
+ continue;
+ }
+ if (varying.name.compare("gl_Position") == 0)
+ {
+ glPositionIsInvariant = varying.isInvariant;
+ }
+ else if (varying.name.compare("gl_PointSize") == 0)
+ {
+ glPointSizeIsInvariant = varying.isInvariant;
+ }
+ }
+
+ for (const sh::Varying &varying : fragmentVaryings)
+ {
+ if (!varying.isBuiltIn())
+ {
+ continue;
+ }
+ if (varying.name.compare("gl_FragCoord") == 0)
+ {
+ glFragCoordIsInvariant = varying.isInvariant;
+ }
+ else if (varying.name.compare("gl_PointCoord") == 0)
+ {
+ glPointCoordIsInvariant = varying.isInvariant;
+ }
+ }
+
+ // There is some ambiguity in ESSL 1.00.17 paragraph 4.6.4 interpretation,
+ // for example, https://cvs.khronos.org/bugzilla/show_bug.cgi?id=13842.
+ // Not requiring invariance to match is supported by:
+ // dEQP, WebGL CTS, Nexus 5X GLES
+ if (glFragCoordIsInvariant && !glPositionIsInvariant)
+ {
+ infoLog << "gl_FragCoord can only be declared invariant if and only if gl_Position is "
+ "declared invariant.";
+ return false;
+ }
+ if (glPointCoordIsInvariant && !glPointSizeIsInvariant)
+ {
+ infoLog << "gl_PointCoord can only be declared invariant if and only if gl_PointSize is "
+ "declared invariant.";
+ return false;
+ }
+
+ return true;
+}
+
bool Program::linkValidateTransformFeedback(InfoLog &infoLog,
const Program::MergedVaryings &varyings,
const Caps &caps) const