Drop QVector for srb and shader stage descriptions

Follow the QRhi changes that move away from QVector in
QRhiShaderResourceBindings and QRhiGraphicsPipeline.

This, together with QRhi's de-d-pointering of QRhiShaderResourceBinding,
is bringing significant performance improvements for scenes with
a lot (thousands) of unbatched items, since a large number of
allocations are now avoided due to not having to create a QVector of
d-pointered classes just to do a lookup in the srb cache.

Change-Id: I612ab2d9449a9e0ce79f7169b942b95d55af61ff
Reviewed-by: Christian Strømme <christian.stromme@qt.io>

2 files changed, 12 insertions, 10 deletions

diff --git a/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp b/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp
index 37deaa35dd..c30ed7cef4 100644
--- a/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp
+++ b/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp
@@ -400,14 +400,14 @@ void ShaderManager::clearCachedRendererData()
     }
 }
 
-QRhiShaderResourceBindings *ShaderManager::srb(const QVector<QRhiShaderResourceBinding> &bindings)
+QRhiShaderResourceBindings *ShaderManager::srb(const ShaderResourceBindingList &bindings)
 {
     auto it = srbCache.constFind(bindings);
     if (it != srbCache.constEnd())
         return *it;
 
     QRhiShaderResourceBindings *srb = context->rhi()->newShaderResourceBindings();
-    srb->setBindings(bindings);
+    srb->setBindings(bindings.cbegin(), bindings.cend());
     if (srb->build()) {
         srbCache.insert(bindings, srb);
     } else {
@@ -3253,7 +3253,7 @@ bool Renderer::ensurePipelineState(Element *e, const ShaderManager::Shader *sms)
 
     // Build a new one. This is potentially expensive.
     QRhiGraphicsPipeline *ps = m_rhi->newGraphicsPipeline();
-    ps->setShaderStages(sms->programRhi.shaderStages);
+    ps->setShaderStages(sms->programRhi.shaderStages.cbegin(), sms->programRhi.shaderStages.cend());
     ps->setVertexInputLayout(sms->programRhi.inputLayout);
     ps->setShaderResourceBindings(e->srb);
     ps->setRenderPassDescriptor(renderPassDescriptor());
@@ -3428,7 +3428,7 @@ static void materialToRendererGraphicsState(GraphicsState *dst,
 void Renderer::updateMaterialDynamicData(ShaderManager::Shader *sms,
                                          QSGMaterialRhiShader::RenderState &renderState,
                                          QSGMaterial *material,
-                                         QVector<QRhiShaderResourceBinding> *bindings,
+                                         ShaderManager::ShaderResourceBindingList *bindings,
                                          const Batch *batch,
                                          int ubufOffset,
                                          int ubufRegionSize) // RHI only, [prepare step]
@@ -3630,7 +3630,7 @@ bool Renderer::prepareRenderMergedBatch(Batch *batch, PreparedRenderBatch *rende
     bool pendingGStatePop = false;
     updateMaterialStaticData(sms, renderState, material, batch, &pendingGStatePop);
 
-    QVector<QRhiShaderResourceBinding> bindings;
+    ShaderManager::ShaderResourceBindingList bindings;
     updateMaterialDynamicData(sms, renderState, material, &bindings, batch, 0, ubufSize);
 
 #ifndef QT_NO_DEBUG
@@ -3824,7 +3824,7 @@ bool Renderer::prepareRenderUnmergedBatch(Batch *batch, PreparedRenderBatch *ren
         }
 
         QSGMaterialRhiShader::RenderState renderState = rhiState(QSGMaterialRhiShader::RenderState::DirtyStates(int(dirty)));
-        QVector<QRhiShaderResourceBinding> bindings;
+        ShaderManager::ShaderResourceBindingList bindings;
         updateMaterialDynamicData(sms, renderState,
                                   material, &bindings, batch, ubufOffset, ubufSize);
 
diff --git a/src/quick/scenegraph/coreapi/qsgbatchrenderer_p.h b/src/quick/scenegraph/coreapi/qsgbatchrenderer_p.h
index 5390e14c77..297df2232a 100644
--- a/src/quick/scenegraph/coreapi/qsgbatchrenderer_p.h
+++ b/src/quick/scenegraph/coreapi/qsgbatchrenderer_p.h
@@ -642,7 +642,7 @@ public:
         struct {
             QSGMaterialRhiShader *program = nullptr;
             QRhiVertexInputLayout inputLayout;
-            QVector<QRhiGraphicsShaderStage> shaderStages;
+            QVarLengthArray<QRhiGraphicsShaderStage, 2> shaderStages;
         } programRhi;
 
         float lastOpacity;
@@ -656,7 +656,9 @@ public:
 
     void clearCachedRendererData();
 
-    QRhiShaderResourceBindings *srb(const QVector<QRhiShaderResourceBinding> &bindings);
+    using ShaderResourceBindingList = QVarLengthArray<QRhiShaderResourceBinding, 8>;
+
+    QRhiShaderResourceBindings *srb(const ShaderResourceBindingList &bindings);
 
 public Q_SLOTS:
     void invalidated();
@@ -672,7 +674,7 @@ private:
     QOpenGLShaderProgram *blitProgram;
     QSGDefaultRenderContext *context;
 
-    QHash<QVector<QRhiShaderResourceBinding>, QRhiShaderResourceBindings *> srbCache;
+    QHash<ShaderResourceBindingList, QRhiShaderResourceBindings *> srbCache;
 };
 
 struct GraphicsState
@@ -797,7 +799,7 @@ private:
     bool ensurePipelineState(Element *e, const ShaderManager::Shader *sms);
     QRhiTexture *dummyTexture();
     void updateMaterialDynamicData(ShaderManager::Shader *sms, QSGMaterialRhiShader::RenderState &renderState,
-                                   QSGMaterial *material, QVector<QRhiShaderResourceBinding> *bindings,
+                                   QSGMaterial *material, ShaderManager::ShaderResourceBindingList *bindings,
                                    const Batch *batch, int ubufOffset, int ubufRegionSize);
     void updateMaterialStaticData(ShaderManager::Shader *sms, QSGMaterialRhiShader::RenderState &renderState,
                                   QSGMaterial *material, Batch *batch, bool *gstateChanged);