Work around Nouveau driver bugs

Change-Id: I25311a2bd88f41087352e0a43ba505f4e27b7e85
Reviewed-by: Jørgen Lind <jorgen.lind@digia.com>

4 files changed, 37 insertions, 7 deletions

diff --git a/src/particles/qquickimageparticle.cpp b/src/particles/qquickimageparticle.cpp
index fa828d7b63..036dfb901e 100644
--- a/src/particles/qquickimageparticle.cpp
+++ b/src/particles/qquickimageparticle.cpp
@@ -1385,6 +1385,12 @@ void QQuickImageParticle::finishBuildParticleNodes()
     }
 #endif
 
+#ifdef Q_OS_LINUX
+    // Nouveau drivers can potentially freeze a machine entirely when taking the point-sprite path.
+    if (perfLevel < Deformable && strstr((char *) glGetString(GL_VENDOR), "nouveau"))
+        perfLevel = Deformable;
+#endif
+
     if (perfLevel >= Colored  && !m_color.isValid())
         m_color = QColor(Qt::white);//Hidden default, but different from unset
 
diff --git a/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp b/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp
index 8514203f57..7a62dccc0f 100644
--- a/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp
+++ b/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp
@@ -1889,7 +1889,14 @@ void Renderer::renderMergedBatch(const Batch *batch)
     updateClip(gn->clipList(), batch);
 
     glBindBuffer(GL_ARRAY_BUFFER, batch->vbo.id);
-    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, batch->vbo.id);
+
+    char *indexBase = 0;
+    if (m_context->hasBrokenIndexBufferObjects()) {
+        indexBase = batch->vbo.data;
+        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+    } else {
+        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, batch->vbo.id);
+    }
 
 
     QSGMaterial *material = gn->activeMaterial();
@@ -1924,7 +1931,7 @@ void Renderer::renderMergedBatch(const Batch *batch)
         }
         glVertexAttribPointer(sms->pos_order, 1, GL_FLOAT, false, 0, (void *) (qintptr) (draw.zorders));
 
-        glDrawElements(g->drawingMode(), draw.indexCount, GL_UNSIGNED_SHORT, (void *) (qintptr) (draw.indices));
+        glDrawElements(g->drawingMode(), draw.indexCount, GL_UNSIGNED_SHORT, (void *) (qintptr) (indexBase + draw.indices));
     }
 }
 
@@ -1957,8 +1964,15 @@ void Renderer::renderUnmergedBatch(const Batch *batch)
     updateClip(gn->clipList(), batch);
 
     glBindBuffer(GL_ARRAY_BUFFER, batch->vbo.id);
-    if (batch->indexCount)
-        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, batch->vbo.id);
+    char *indexBase = 0;
+    if (batch->indexCount) {
+        if (m_context->hasBrokenIndexBufferObjects()) {
+            indexBase = batch->vbo.data;
+            glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+        } else {
+            glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, batch->vbo.id);
+        }
+    }
 
     // We always have dirty matrix as all batches are at a unique z range.
     QSGMaterialShader::RenderState::DirtyStates dirty = QSGMaterialShader::RenderState::DirtyMatrix;
@@ -1977,7 +1991,7 @@ void Renderer::renderUnmergedBatch(const Batch *batch)
     }
 
     int vOffset = 0;
-    int iOffset = batch->vertexCount * gn->geometry()->sizeOfVertex();
+    char *iOffset = indexBase + batch->vertexCount * gn->geometry()->sizeOfVertex();
 
     QMatrix4x4 rootMatrix = batch->root ? matrixForRoot(batch->root) : QMatrix4x4();
 
@@ -2008,7 +2022,7 @@ void Renderer::renderUnmergedBatch(const Batch *batch)
         }
 
         if (g->indexCount())
-            glDrawElements(g->drawingMode(), g->indexCount(), g->indexType(), (void *) (qintptr) iOffset);
+            glDrawElements(g->drawingMode(), g->indexCount(), g->indexType(), iOffset);
         else
             glDrawArrays(g->drawingMode(), 0, g->vertexCount());
 
diff --git a/src/quick/scenegraph/qsgcontext.cpp b/src/quick/scenegraph/qsgcontext.cpp
index 558711ea0e..4fbefb37d8 100644
--- a/src/quick/scenegraph/qsgcontext.cpp
+++ b/src/quick/scenegraph/qsgcontext.cpp
@@ -311,6 +311,7 @@ QSGRenderContext::QSGRenderContext(QSGContext *context)
     , m_atlasManager(0)
     , m_depthStencilManager(0)
     , m_distanceFieldCacheManager(0)
+    , m_brokenIBOs(false)
 {
 }
 
@@ -408,6 +409,12 @@ void QSGRenderContext::initialize(QOpenGLContext *context)
     m_gl->setProperty(QSG_RENDERCONTEXT_PROPERTY, QVariant::fromValue(this));
     m_sg->renderContextInitialized(this);
 
+#ifdef Q_OS_LINUX
+    const char *vendor = (const char *) glGetString(GL_VENDOR);
+    if (strstr(vendor, "nouveau"))
+        m_brokenIBOs = true;
+#endif
+
     emit initialized();
 }
 
diff --git a/src/quick/scenegraph/qsgcontext_p.h b/src/quick/scenegraph/qsgcontext_p.h
index a11a4856c4..08fafb0713 100644
--- a/src/quick/scenegraph/qsgcontext_p.h
+++ b/src/quick/scenegraph/qsgcontext_p.h
@@ -109,11 +109,12 @@ public:
 
     static QSGRenderContext *from(QOpenGLContext *context);
 
+    bool hasBrokenIndexBufferObjects() const { return m_brokenIBOs; }
+
 Q_SIGNALS:
     void initialized();
     void invalidated();
 
-
 public Q_SLOTS:
     void textureFactoryDestroyed(QObject *o);
 
@@ -129,6 +130,8 @@ protected:
     QSGDistanceFieldGlyphCacheManager *m_distanceFieldCacheManager;
 
     QSet<QFontEngine *> m_fontEnginesToClean;
+
+    bool m_brokenIBOs;
 };