Shader fixes

- Make sure that shaders marked for destruction are un marked from
  destruction if recreated before having been destroyed.

- When loading shaders, make sure the shader wasn't already loaded
  when loading it. This can happen is a shader is abandoned and then
  re adopted.

Change-Id: I04597479d782bc6d31e4c7f78425c02c31217c7e
Reviewed-by: Mike Krus <mike.krus@kdab.com>

1 files changed, 12 insertions, 9 deletions

diff --git a/src/plugins/renderers/opengl/graphicshelpers/graphicscontext.cpp b/src/plugins/renderers/opengl/graphicshelpers/graphicscontext.cpp
index a4152449f..f52a358ad 100644
--- a/src/plugins/renderers/opengl/graphicshelpers/graphicscontext.cpp
+++ b/src/plugins/renderers/opengl/graphicshelpers/graphicscontext.cpp
@@ -233,7 +233,7 @@ void GraphicsContext::doneCurrent()
     m_glHelper = nullptr;
 }
 
-// Called by GL Command Thread
+// Called by GraphicsContext::loadShader itself called by Renderer::updateGLResources
 GraphicsContext::ShaderCreationInfo GraphicsContext::createShaderProgram(GLShader *shader)
 {
     QOpenGLShaderProgram *shaderProgram = shader->shaderProgram();
@@ -303,14 +303,17 @@ void GraphicsContext::loadShader(Shader *shaderNode,
 
     const QVector<Qt3DCore::QNodeId> sharedShaderIds = glShaderManager->shaderIdsForProgram(glShader);
     if (sharedShaderIds.size() == 1) {
-        // Shader in the cache hasn't been loaded yet
-        glShader->setGraphicsContext(this);
-        glShader->setShaderCode(shaderNode->shaderCode());
-        const ShaderCreationInfo loadResult = createShaderProgram(glShader);
-        shaderNode->setStatus(loadResult.linkSucceeded ? QShaderProgram::Ready : QShaderProgram::Error);
-        shaderNode->setLog(loadResult.logs);
-        // Loaded in the sense we tried to load it (and maybe it failed)
-        glShader->setLoaded(true);
+        // The Shader could already be loaded if we retrieved one
+        // that had been marked for destruction
+        if (!glShader->isLoaded()) {
+            glShader->setGraphicsContext(this);
+            glShader->setShaderCode(shaderNode->shaderCode());
+            const ShaderCreationInfo loadResult = createShaderProgram(glShader);
+            shaderNode->setStatus(loadResult.linkSucceeded ? QShaderProgram::Ready : QShaderProgram::Error);
+            shaderNode->setLog(loadResult.logs);
+            // Loaded in the sense we tried to load it (and maybe it failed)
+            glShader->setLoaded(true);
+        }
     } else {
         // Find an already loaded shader that shares the same QOpenGLShaderProgram
         for (const Qt3DCore::QNodeId sharedShaderId : sharedShaderIds) {