qgsmesh3dmaterial: Ensure to create valid textures for the fragment s…

…hader In the shader code, all the parameters need to be properly initialized even if they are not used. Otherwise, this can create undefined behaviors and some missing meshes in a 3d scene. In the current code, there are two parameters which may not be properly initialized: - "colorRampTexture" is not set if the color ramp mode is not set - "arrowsGridTexture" texture image is invalid if the "display arrows" mode is disabled The first issue ("colorRampTexture") is solved by creating a dummy valid texture image if the color ramp mode is disabled and setting the "colorRampTexture" parameter in all cases. This does not change anything in the shader code. The parameter is not used. The shader only needs a valid parameter. The second issue ("arrowsGridTexture") is solved by setting proper default values for the parameters which generate the arrows grid texture. This ensure to generate a valid texture image . This also does not change anything in the shader code. The parameter is not used. The shader only needs a valid parameter.
qgis · Sep 29, 2023 · ec6e480 · ec6e480
1 parent 8c57166
commit ec6e480
Showing 1 changed file with 12 additions and 8 deletions.
diff --git a/src/3d/mesh/qgsmesh3dmaterial_p.cpp b/src/3d/mesh/qgsmesh3dmaterial_p.cpp
@@ -132,10 +132,9 @@ QgsMesh3dMaterial::QgsMesh3dMaterial( QgsMeshLayer *layer,
 void QgsMesh3dMaterial::configure()
 {
   // Create the texture to pass the color ramp
-  Qt3DRender::QTexture1D *colorRampTexture = nullptr;
+  Qt3DRender::QTexture1D *colorRampTexture = new Qt3DRender::QTexture1D( this );
   if ( mSymbol->colorRampShader().colorRampItemList().count() > 0 )
   {
-    colorRampTexture = new Qt3DRender::QTexture1D( this );
     switch ( mMagnitudeType )
     {
       case QgsMesh3dMaterial::ZValue:
@@ -148,9 +147,15 @@ void QgsMesh3dMaterial::configure()
         break;
     }
 
-    colorRampTexture->setMinificationFilter( Qt3DRender::QTexture1D::Linear );
-    colorRampTexture->setMagnificationFilter( Qt3DRender::QTexture1D::Linear );
   }
+  else
+  {
+    // create a simple texture to have a valid parameter in the shader and avoid undefined behaviors
+    colorRampTexture->addTextureImage( new QgsColorRampTexture( QgsColorRampShader(), 1 ) );
+  }
+
+  colorRampTexture->setMinificationFilter( Qt3DRender::QTexture1D::Linear );
+  colorRampTexture->setMagnificationFilter( Qt3DRender::QTexture1D::Linear );
 
   // Create and configure technique
   mTechnique = new Qt3DRender::QTechnique();
@@ -184,8 +189,7 @@ void QgsMesh3dMaterial::configure()
   mTechnique->addParameter( new Qt3DRender::QParameter( "lineColor", QVector4D( wireframecolor.redF(), wireframecolor.greenF(), wireframecolor.blueF(), 1.0f ) ) );
   mTechnique->addParameter( new Qt3DRender::QParameter( "wireframeEnabled", mSymbol->wireframeEnabled() ) );
   mTechnique->addParameter( new Qt3DRender::QParameter( "textureType", int( mSymbol->renderingStyle() ) ) );
-  if ( colorRampTexture )
-    mTechnique->addParameter( new Qt3DRender::QParameter( "colorRampTexture", colorRampTexture ) ) ;
+  mTechnique->addParameter( new Qt3DRender::QParameter( "colorRampTexture", colorRampTexture ) ) ;
   mTechnique->addParameter( new Qt3DRender::QParameter( "colorRampCount", mSymbol->colorRampShader().colorRampItemList().count() ) );
   const int colorRampType = mSymbol->colorRampShader().colorRampType();
   mTechnique->addParameter( new Qt3DRender::QParameter( "colorRampType", colorRampType ) );
@@ -203,8 +207,8 @@ void QgsMesh3dMaterial::configureArrows( QgsMeshLayer *layer, const QgsDateTimeR
   if ( layer )
     datasetIndex = layer->activeVectorDatasetAtTime( timeRange );
 
-  QVector<QgsVector> vectors;
-  QSize gridSize;
+  QVector<QgsVector> vectors( 1 );
+  QSize gridSize( 1, 1 );
   QgsPointXY minCorner;
   std::unique_ptr< Qt3DRender::QParameter > arrowsEnabledParameter = std::make_unique< Qt3DRender::QParameter >( "arrowsEnabled", nullptr );
   if ( !layer || mMagnitudeType != MagnitudeType::ScalarDataSet || !mSymbol->arrowsEnabled() || meta.isScalar() || !datasetIndex.isValid() )