Do not share textures in Dragon if they are used for render targets

Change-Id: I57a3b53ee5b520337efc2bf80d6f729614939fa8
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

1 files changed, 13 insertions, 1 deletions

diff --git a/src/runtime/dragon/dragonrenderer.cpp b/src/runtime/dragon/dragonrenderer.cpp
index afe93db..826f04f 100644
--- a/src/runtime/dragon/dragonrenderer.cpp
+++ b/src/runtime/dragon/dragonrenderer.cpp
@@ -357,12 +357,18 @@ Renderer::Frame Renderer::doRender(Renderer::Frame frame)
         Immutable<RenderView> renderView;
     };
 
+    QVector<QNodeId> texturesUsedInRenderTargets;
     QHash<QSurface *, QVector<SurfaceInfo>> surfaceViews; // ordered
     for (const auto &leafNodeId : leafNodes) {
         // TODO IMPORTANT make sure the views are ordered correctly regardless of surface differences
         const auto &renderView = renderViews[leafNodeId];
         SurfaceInfo info { leafNodeId, renderView };
         surfaceViews[renderView->surface].push_back(info);
+
+        // We need a list of texture IDs that are used in render targets and hence cannot be shared
+        for (const auto &renderTarget : renderView->attachmentPack.outputs) {
+            texturesUsedInRenderTargets.push_back(renderTarget->textureUuid);
+        }
     }
 
     bool preparationsComplete = false;
@@ -403,7 +409,13 @@ Renderer::Frame Renderer::doRender(Renderer::Frame frame)
                     return Mutable<GLTexture>(createGlTexture(loadedTexture, activeSurface.openGLContext()));
             };
 
-            auto compareGLTexture = [](const GLTexture &glTexture, const Immutable<LoadedTexture> &loaded){
+            auto compareGLTexture = [texturesUsedInRenderTargets](const GLTexture &glTexture, const Immutable<LoadedTexture> &loaded){
+                // If a texture is used in a render target, it cannot share GLTexture with other textures
+                // TODO Consider separating the concept of any texture and one that is being rendered to, at least on the backend
+                if (texturesUsedInRenderTargets.contains(glTexture.loadedTexture->texture->peerId())
+                        || texturesUsedInRenderTargets.contains(loaded->texture->peerId()))
+                    return false;
+
                 return glTexture.loadedTexture == loaded;
             };