Add osg::Program wrapper for error-reporting

simgear/scene/material/Effect.cxx

@@ -73,6 +73,7 @@
 #include <simgear/props/vectorPropTemplates.hxx>
 #include <simgear/scene/tgdb/userdata.hxx>
 #include <simgear/scene/util/OsgMath.hxx>
+#include <simgear/scene/util/SGProgram.hxx>
 #include <simgear/scene/util/SGReaderWriterOptions.hxx>
 #include <simgear/scene/util/SGSceneFeatures.hxx>
 #include <simgear/scene/util/StateAttributeFactory.hxx>
@@ -107,6 +108,7 @@ bool loadShaderFromUTF8File(osg::Shader* shader, const std::string& fileName)
     if (!inStream.is_open())
         return false;
 
+    shader->setFileName(fileName);
     shader->setShaderSource(inStream.read_all());
     return true;
 }
@@ -959,7 +961,7 @@ void ShaderProgramBuilder::buildAttribute(Effect* effect, Pass* pass,
         pass->setAttributeAndModes(program);
         return;
     }
-    program = new Program;
+    program = new SGProgram;
     for (const auto& skey : resolvedKey.shaders) {
         const string& fileName = skey.first;
         Shader::Type stype = (Shader::Type)skey.second;

simgear/scene/util/CMakeLists.txt

@@ -31,6 +31,7 @@ set(HEADERS
     UpdateOnceCallback.hxx
     VectorArrayAdapter.hxx
     project.hxx
+    SGProgram.hxx
     )
 
 set(SOURCES
@@ -55,6 +56,7 @@ set(SOURCES
     StateAttributeFactory.cxx
     UpdateOnceCallback.cxx
     project.cxx
+    SGProgram.cxx
     )
 
 simgear_scene_component(util scene/util "${SOURCES}" "${HEADERS}")

simgear/scene/util/SGProgram.cxx

@@ -0,0 +1,61 @@
+////
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Library General Public
+// License as published by the Free Software Foundation; either
+// version 2 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Library General Public License for more details.
+//
+// You should have received a copy of the GNU Library General Public
+// License along with this library; if not, write to the
+// Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+// Boston, MA  02110-1301, USA.
+
+
+#include "simgear_config.h"
+
+#include "SGProgram.hxx"
+
+#include <osg/State>
+
+#include <simgear/debug/ErrorReportingCallback.hxx>
+
+SGProgram::SGProgram(const SGProgram& rhs, const osg::CopyOp& copyop) : osg::Program(rhs, copyop)
+{
+}
+
+void SGProgram::apply(osg::State& state) const
+{
+    osg::Program::apply(state);
+
+    if (_checkState != NotApplied) {
+        return; // already done
+    }
+
+    auto pcp = state.getLastAppliedProgramObject();
+    if (!pcp) {
+        std::string infoLog;
+        _checkState = FailedToApply;
+        getPCP(state)->getInfoLog(infoLog);
+
+        simgear::reportFailure(simgear::LoadFailure::BadData, simgear::ErrorCode::LoadEffectsShaders,
+                               "Shader program errors: " + infoLog, sg_location());
+
+        for (int i = 0; i < getNumShaders(); ++i) {
+            const auto shader = getShader(i);
+            auto pcs = shader->getPCS(state);
+
+            std::string shaderLog;
+            pcs->getInfoLog(shaderLog);
+            if (!shaderLog.empty()) {
+                simgear::reportFailure(simgear::LoadFailure::BadData, simgear::ErrorCode::LoadEffectsShaders,
+                                       "Shader source errors: " + shaderLog, sg_location(shader->getFileName()));
+            }
+        }
+    } else {
+        _checkState = AppliedOk;
+    }
+}

simgear/scene/util/SGProgram.hxx

@@ -0,0 +1,45 @@
+////
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Library General Public
+// License as published by the Free Software Foundation; either
+// version 2 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Library General Public License for more details.
+//
+// You should have received a copy of the GNU Library General Public
+// License along with this library; if not, write to the
+// Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+// Boston, MA  02110-1301, USA.
+
+#pragma once
+
+#include <osg/Program>
+
+/**
+ * @brief wrapper around osg::Program to allow detecting shader/link
+ * errors in the GLSL code at runtime, and reporting of them
+ * 
+ */
+class SGProgram : public osg::Program
+{
+public:
+    SGProgram() = default;
+
+    SGProgram(const SGProgram& rhs, const osg::CopyOp& copyop = osg::CopyOp::SHALLOW_COPY);
+
+    META_StateAttribute(simgear, SGProgram, PROGRAM);
+
+    void apply(osg::State& state) const override;
+
+    enum ErrorCheckState {
+        NotApplied,
+        AppliedOk,
+        FailedToApply
+    };
+
+private:
+    mutable ErrorCheckState _checkState = NotApplied;
+};