rhi: set primitive type on graphics pipeline

Otherwise we are ignoring the primitive type specified by the user and drawing
everything with triangles.

Note: rhi doesn't handle all primitive types (lineloop, patches and adjancency
primitives are currently not supported).

Change-Id: Ic025917c37413b7e062b8c0b17d506822270d924
Reviewed-by: Mike Krus <mike.krus@kdab.com>

3 files changed, 48 insertions, 2 deletions

diff --git a/src/plugins/renderers/rhi/managers/rhiresourcemanagers_p.h b/src/plugins/renderers/rhi/managers/rhiresourcemanagers_p.h
index 7269bae8f..b5dc67aee 100644
--- a/src/plugins/renderers/rhi/managers/rhiresourcemanagers_p.h
+++ b/src/plugins/renderers/rhi/managers/rhiresourcemanagers_p.h
@@ -157,6 +157,7 @@ inline uint qHash(const GraphicsPipelineIdentifier &key, uint seed = 0)
     seed = qHash(p, seed);
     seed = qHash(key.renderTarget, seed);
     seed = qHash(key.renderViewIndex, seed);
+    seed = qHash(key.primitiveType, seed);
     return seed;
 }
 
@@ -165,7 +166,8 @@ inline bool operator==(const GraphicsPipelineIdentifier &a, const GraphicsPipeli
     return a.geometryLayoutKey == b.geometryLayoutKey &&
            a.shader == b.shader &&
            a.renderTarget == b.renderTarget &&
-           a.renderViewIndex == b.renderViewIndex;
+           a.renderViewIndex == b.renderViewIndex &&
+           a.primitiveType == b.primitiveType;
 }
 
 inline uint qHash(const ComputePipelineIdentifier &key, uint seed = 0)
diff --git a/src/plugins/renderers/rhi/renderer/renderer.cpp b/src/plugins/renderers/rhi/renderer/renderer.cpp
index d09cf07bb..aea3e7e4c 100644
--- a/src/plugins/renderers/rhi/renderer/renderer.cpp
+++ b/src/plugins/renderers/rhi/renderer/renderer.cpp
@@ -868,7 +868,7 @@ void Renderer::updateGraphicsPipeline(RenderCommand &cmd, RenderView *rv,
     // as it is likely many geometrys will have the same layout
     RHIGraphicsPipelineManager *pipelineManager = m_RHIResourceManagers->rhiGraphicsPipelineManager();
     const int geometryLayoutId = pipelineManager->getIdForAttributeVec(cmd.m_attributeInfo);
-    const GraphicsPipelineIdentifier pipelineKey { geometryLayoutId, cmd.m_shaderId, rv->renderTargetId(), renderViewIndex };
+    const GraphicsPipelineIdentifier pipelineKey { geometryLayoutId, cmd.m_shaderId, rv->renderTargetId(), cmd.m_primitiveType, renderViewIndex };
     RHIGraphicsPipeline *graphicsPipeline = pipelineManager->lookupResource(pipelineKey);
     if (graphicsPipeline == nullptr) {
         // Init UBOSet the first time we allocate a new pipeline
@@ -980,6 +980,48 @@ void Renderer::buildGraphicsPipelines(RHIGraphicsPipeline *graphicsPipeline,
 
     pipeline->setShaderResourceBindings(shaderResourceBindings);
 
+    auto rhiTopologyFromQt3DTopology = [] (const Qt3DRender::QGeometryRenderer::PrimitiveType t) {
+        switch (t) {
+        case Qt3DRender::QGeometryRenderer::Points:
+        return QRhiGraphicsPipeline::Points;
+
+        case Qt3DRender::QGeometryRenderer::Lines:
+        return QRhiGraphicsPipeline::Lines;
+
+        case Qt3DRender::QGeometryRenderer::LineStrip:
+            return QRhiGraphicsPipeline::LineStrip;
+
+        case Qt3DRender::QGeometryRenderer::Triangles:
+        return QRhiGraphicsPipeline::Triangles;
+
+        case Qt3DRender::QGeometryRenderer::TriangleStrip:
+            return QRhiGraphicsPipeline::TriangleStrip;
+
+        case Qt3DRender::QGeometryRenderer::TriangleFan:
+            return QRhiGraphicsPipeline::TriangleFan;
+
+        case Qt3DRender::QGeometryRenderer::LineLoop: {
+            qWarning(Backend) << "LineLoop primitive type is not handled by RHI";
+            return QRhiGraphicsPipeline::Lines;
+        }
+
+        case Qt3DRender::QGeometryRenderer::Patches: {
+            qWarning(Backend) << "Patches primitive type is not handled by RHI";
+            return QRhiGraphicsPipeline::Points;
+        }
+
+        case Qt3DRender::QGeometryRenderer::LinesAdjacency:
+        case Qt3DRender::QGeometryRenderer::TrianglesAdjacency:
+        case Qt3DRender::QGeometryRenderer::LineStripAdjacency:
+        case Qt3DRender::QGeometryRenderer::TriangleStripAdjacency: {
+            qWarning(Backend) << "Adjancency primitive types are not handled by RHI";
+            return QRhiGraphicsPipeline::Points;
+        }
+        }
+    };
+
+    pipeline->setTopology(rhiTopologyFromQt3DTopology(cmd.m_primitiveType));
+
     QRhiVertexInputLayout inputLayout;
     inputLayout.setBindings(inputBindings.begin(), inputBindings.end());
     inputLayout.setAttributes(rhiAttributes.begin(), rhiAttributes.end());
diff --git a/src/plugins/renderers/rhi/renderer/rhigraphicspipeline_p.h b/src/plugins/renderers/rhi/renderer/rhigraphicspipeline_p.h
index bbd311ac1..52803deb0 100644
--- a/src/plugins/renderers/rhi/renderer/rhigraphicspipeline_p.h
+++ b/src/plugins/renderers/rhi/renderer/rhigraphicspipeline_p.h
@@ -56,6 +56,7 @@
 #include <pipelineuboset_p.h>
 #include <Qt3DCore/qnodeid.h>
 #include <Qt3DRender/private/handle_types_p.h>
+#include <Qt3DRender/qgeometryrenderer.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -73,6 +74,7 @@ struct GraphicsPipelineIdentifier
     int geometryLayoutKey;
     Qt3DCore::QNodeId shader;
     Qt3DCore::QNodeId renderTarget;
+    Qt3DRender::QGeometryRenderer::PrimitiveType primitiveType;
     int renderViewIndex = 0;
 };