Add a "shocking pink" shader for rendering into stencil buff

If you see shocking pink in the rendering output, it's probably because
the "simple" shader is in use but color writes have somehow been
enabled. :-)

3 files changed, 30 insertions, 2 deletions

diff --git a/src/opengl/gl2paintengineex/qglengineshadermanager.cpp b/src/opengl/gl2paintengineex/qglengineshadermanager.cpp
index 1253414..7c165ae 100644
--- a/src/opengl/gl2paintengineex/qglengineshadermanager.cpp
+++ b/src/opengl/gl2paintengineex/qglengineshadermanager.cpp
@@ -111,6 +111,7 @@ QGLEngineShaderManager::QGLEngineShaderManager(QGLContext* context)
         code[LinearGradientBrushSrcFragmentShader] = qglslLinearGradientBrushSrcFragmentShader;
         code[RadialGradientBrushSrcFragmentShader] = qglslRadialGradientBrushSrcFragmentShader;
         code[ConicalGradientBrushSrcFragmentShader] = qglslConicalGradientBrushSrcFragmentShader;
+        code[ShockingPinkSrcFragmentShader] = qglslShockingPinkSrcFragmentShader;
 
         code[MaskFragmentShader] = qglslMaskFragmentShader;
         code[RgbMaskFragmentShader] = ""; //###
@@ -131,12 +132,33 @@ QGLEngineShaderManager::QGLEngineShaderManager(QGLContext* context)
 #if defined(QT_DEBUG)
         // Check that all the elements have been filled:
         for (int i = 0; i < TotalShaderCount; ++i) {
-            if (qglEngineShaderSourceCode[i] == 0)
-                qCritical() << "qglEngineShaderSourceCode: Missing shader in element" << i;
+            if (qglEngineShaderSourceCode[i] == 0) {
+                int enumIndex = staticMetaObject.indexOfEnumerator("ShaderName");
+                QMetaEnum m = staticMetaObject.enumerator(enumIndex);
+
+                qCritical() << "qglEngineShaderSourceCode: Source for" << m.valueToKey(i)
+                            << "(shader" << i << ") missing!";
+            }
         }
 #endif
         qglEngineShaderSourceCodePopulated = true;
     }
+
+    // Compile up the simple shader:
+    simpleShaderProg = new QGLShaderProgram(ctx, this);
+    compileNamedShader(MainVertexShader,              QGLShader::PartialVertexShader);
+    compileNamedShader(PositionOnlyVertexShader,      QGLShader::PartialVertexShader);
+    compileNamedShader(MainFragmentShader,            QGLShader::PartialFragmentShader);
+    compileNamedShader(ShockingPinkSrcFragmentShader, QGLShader::PartialFragmentShader);
+    simpleShaderProg->addShader(compiledShaders[MainVertexShader]);
+    simpleShaderProg->addShader(compiledShaders[PositionOnlyVertexShader]);
+    simpleShaderProg->addShader(compiledShaders[MainFragmentShader]);
+    simpleShaderProg->addShader(compiledShaders[ShockingPinkSrcFragmentShader]);
+    simpleShaderProg->link();
+    if (!simpleShaderProg->isValid()) {
+        qCritical() << "Errors linking simple shader:"
+                    << simpleShaderProg->errors();
+    }
 }
 
 QGLEngineShaderManager::~QGLEngineShaderManager()
diff --git a/src/opengl/gl2paintengineex/qglengineshadermanager_p.h b/src/opengl/gl2paintengineex/qglengineshadermanager_p.h
index 38c1cff..61a62dc 100644
--- a/src/opengl/gl2paintengineex/qglengineshadermanager_p.h
+++ b/src/opengl/gl2paintengineex/qglengineshadermanager_p.h
@@ -317,6 +317,7 @@ public:
         LinearGradientBrushSrcFragmentShader,
         RadialGradientBrushSrcFragmentShader,
         ConicalGradientBrushSrcFragmentShader,
+        ShockingPinkSrcFragmentShader,
 
         MaskFragmentShader,
         RgbMaskFragmentShader,
diff --git a/src/opengl/gl2paintengineex/qglengineshadersource_p.h b/src/opengl/gl2paintengineex/qglengineshadersource_p.h
index 3aa1a36..d605b01 100644
--- a/src/opengl/gl2paintengineex/qglengineshadersource_p.h
+++ b/src/opengl/gl2paintengineex/qglengineshadersource_p.h
@@ -288,6 +288,11 @@ static const char* const qglslNonPremultipliedImageSrcFragmentShader = "\
         return sample; \
     }";
 
+static const char* const qglslShockingPinkSrcFragmentShader = "\
+    lowp vec4 srcPixel() { \
+        return lowp vec4(0.98, 0.06, 0.75, 1.0); \
+    }";
+
 
 static const char* const qglslMainFragmentShader_CMO = "\
     uniform lowp float globalOpacity; \