ES2 support for scatter points

Task-number: QTRD-2539

Change-Id: I2465322d9a4341ce4c345756fe085a4c5ad2be5b
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@digia.com>

5 files changed, 58 insertions, 11 deletions

diff --git a/src/datavisualization/engine/engine.qrc b/src/datavisualization/engine/engine.qrc
index de4a04da..14fb1bc6 100644
--- a/src/datavisualization/engine/engine.qrc
+++ b/src/datavisualization/engine/engine.qrc
@@ -56,6 +56,7 @@
         <file alias="vertexSurfaceFlat">shaders/surfaceFlat.vert</file>
         <file alias="fragmentSurfaceFlat">shaders/surfaceFlat.frag</file>
         <file alias="fragmentSurfaceES2">shaders/surface_ES2.frag</file>
+        <file alias="vertexPointES2">shaders/point_ES2.vert</file>
     </qresource>
     <qresource prefix="/textures"/>
 </RCC>
diff --git a/src/datavisualization/engine/scatter3dcontroller.cpp b/src/datavisualization/engine/scatter3dcontroller.cpp
index 065f1f02..0786ad18 100644
--- a/src/datavisualization/engine/scatter3dcontroller.cpp
+++ b/src/datavisualization/engine/scatter3dcontroller.cpp
@@ -203,6 +203,9 @@ void Scatter3DController::setObjectType(QDataVis::MeshStyle style, bool smooth)
             objFile = QStringLiteral(":/defaultMeshes/dot");
     } else {
         objFile = QString();
+#if defined(QT_OPENGL_ES_2)
+        qWarning("MeshStylePoints is not fully supported on OpenGL ES2");
+#endif
     }
     Abstract3DController::setMeshFileName(objFile);
 }
diff --git a/src/datavisualization/engine/scatter3drenderer.cpp b/src/datavisualization/engine/scatter3drenderer.cpp
index 70c7e107..3ebbbf74 100644
--- a/src/datavisualization/engine/scatter3drenderer.cpp
+++ b/src/datavisualization/engine/scatter3drenderer.cpp
@@ -58,6 +58,9 @@ Scatter3DRenderer::Scatter3DRenderer(Scatter3DController *controller)
       m_yFlipped(false),
       m_updateLabels(false),
       m_dotShader(0),
+      #if defined(QT_OPENGL_ES_2)
+      m_pointShader(0),
+      #endif
       m_depthShader(0),
       m_selectionShader(0),
       m_backgroundShader(0),
@@ -115,6 +118,9 @@ void Scatter3DRenderer::initializeOpenGL()
 #if !defined(QT_OPENGL_ES_2)
     // Init depth shader (for shadows). Init in any case, easier to handle shadow activation if done via api.
     initDepthShader();
+#else
+    // Init point shader
+    initPointShader();
 #endif
 
     // Init selection shader
@@ -274,13 +280,14 @@ void Scatter3DRenderer::drawScene(const GLuint defaultFboHandle)
     QMatrix4x4 depthProjectionMatrix;
     QMatrix4x4 depthProjectionViewMatrix;
 
+#if !defined(QT_OPENGL_ES_2)
     if (m_drawingPoints) {
         glEnable(GL_POINT_SMOOTH);
         glEnable(GL_PROGRAM_POINT_SIZE);
-        glPointSize(m_dotSizeScale * 100.0f); // Don't scale points based on zoom for shadows
+        // Scale points based on shadow quality for shadows, not by zoom level
+        glPointSize(m_dotSizeScale * 100.0f * m_shadowQualityMultiplier);
     }
 
-#if !defined(QT_OPENGL_ES_2)
     if (m_cachedShadowQuality > QDataVis::ShadowQualityNone) {
         // Render scene into a depth texture for using with shadow mapping
         // Bind depth shader
@@ -392,16 +399,24 @@ void Scatter3DRenderer::drawScene(const GLuint defaultFboHandle)
         m_labelShader->release();
 #endif
     }
-#endif
 
     if (m_drawingPoints)
         glPointSize(m_dotSizeScale * activeCamera->zoomLevel()); // Scale points based on zoom
 
+    ShaderHelper *selectionShader = m_selectionShader;
+#else
+    ShaderHelper *selectionShader;
+    if (m_drawingPoints)
+        selectionShader = m_pointShader;
+    else
+        selectionShader = m_selectionShader;
+#endif
+
     // Skip selection mode drawing if we have no selection mode
     if (m_cachedSelectionMode > QDataVis::SelectionNone
             && QDataVis::InputStateOnScene == m_inputState) {
         // Bind selection shader
-        m_selectionShader->bind();
+        selectionShader->bind();
 
         // Draw dots to selection buffer
         glBindFramebuffer(GL_FRAMEBUFFER, m_selectionFrameBuffer);
@@ -435,16 +450,16 @@ void Scatter3DRenderer::drawScene(const GLuint defaultFboHandle)
             QVector3D dotColor = indexToSelectionColor(dot);
             dotColor /= 255.0f;
 
-            m_selectionShader->setUniformValue(m_selectionShader->MVP(), MVPMatrix);
-            m_selectionShader->setUniformValue(m_selectionShader->color(), dotColor);
+            selectionShader->setUniformValue(selectionShader->MVP(), MVPMatrix);
+            selectionShader->setUniformValue(selectionShader->color(), dotColor);
 
             if (m_drawingPoints) {
-                m_drawer->drawPoint(m_selectionShader);
+                m_drawer->drawPoint(selectionShader);
             } else {
                 // 1st attribute buffer : vertices
-                glEnableVertexAttribArray(m_selectionShader->posAtt());
+                glEnableVertexAttribArray(selectionShader->posAtt());
                 glBindBuffer(GL_ARRAY_BUFFER, m_dotObj->vertexBuf());
-                glVertexAttribPointer(m_selectionShader->posAtt(), 3, GL_FLOAT, GL_FALSE, 0, (void *)0);
+                glVertexAttribPointer(selectionShader->posAtt(), 3, GL_FLOAT, GL_FALSE, 0, (void *)0);
 
                 // Index buffer
                 glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_dotObj->elementBuf());
@@ -456,7 +471,7 @@ void Scatter3DRenderer::drawScene(const GLuint defaultFboHandle)
                 glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
                 glBindBuffer(GL_ARRAY_BUFFER, 0);
 
-                glDisableVertexAttribArray(m_selectionShader->posAtt());
+                glDisableVertexAttribArray(selectionShader->posAtt());
             }
         }
         glEnable(GL_DITHER);
@@ -473,7 +488,7 @@ void Scatter3DRenderer::drawScene(const GLuint defaultFboHandle)
         glBindFramebuffer(GL_FRAMEBUFFER, defaultFboHandle);
 
         // Release selection shader
-        m_selectionShader->release();
+        selectionShader->release();
 
 #if 0 // Use this if you want to see what is being drawn to the framebuffer
         m_labelShader->bind();
@@ -507,7 +522,11 @@ void Scatter3DRenderer::drawScene(const GLuint defaultFboHandle)
         glEnable(GL_TEXTURE_2D);
     } else {
         // We can use selection shader for points
+#if !defined(QT_OPENGL_ES_2)
         dotShader = m_selectionShader;
+#else
+        dotShader = m_pointShader;
+#endif
         dotShader->bind();
     }
 
@@ -604,11 +623,13 @@ void Scatter3DRenderer::drawScene(const GLuint defaultFboHandle)
     // Release dot shader
     dotShader->release();
 
+#if !defined(QT_OPENGL_ES_2)
     if (m_drawingPoints) {
         glDisable(GL_POINT_SMOOTH);
         glDisable(GL_PROGRAM_POINT_SIZE);
         glEnable(GL_TEXTURE_2D); // Enable texturing for background
     }
+#endif
 
     // Bind background shader
     m_backgroundShader->bind();
@@ -1564,6 +1585,15 @@ void Scatter3DRenderer::updateDepthBuffer()
             lowerShadowQuality();
     }
 }
+#else
+void Scatter3DRenderer::initPointShader()
+{
+    if (m_pointShader)
+        delete m_pointShader;
+    m_pointShader = new ShaderHelper(this, QStringLiteral(":/shaders/vertexPointES2"),
+                                     QStringLiteral(":/shaders/fragmentSelection"));
+    m_pointShader->initialize();
+}
 #endif
 
 void Scatter3DRenderer::initBackgroundShaders(const QString &vertexShader,
diff --git a/src/datavisualization/engine/scatter3drenderer_p.h b/src/datavisualization/engine/scatter3drenderer_p.h
index 36492e80..b74f2118 100644
--- a/src/datavisualization/engine/scatter3drenderer_p.h
+++ b/src/datavisualization/engine/scatter3drenderer_p.h
@@ -60,6 +60,9 @@ private:
     QRect m_mainViewPort;
     bool m_updateLabels;
     ShaderHelper *m_dotShader;
+#if defined(QT_OPENGL_ES_2)
+    ShaderHelper *m_pointShader;
+#endif
     ShaderHelper *m_depthShader;
     ShaderHelper *m_selectionShader;
     ShaderHelper *m_backgroundShader;
@@ -122,6 +125,8 @@ private:
 #if !defined(QT_OPENGL_ES_2)
     void initDepthShader();
     void updateDepthBuffer();
+#else
+    void initPointShader();
 #endif
     void calculateTranslation(ScatterRenderItem &item);
     void calculateSceneScalingFactors();
diff --git a/src/datavisualization/engine/shaders/point_ES2.vert b/src/datavisualization/engine/shaders/point_ES2.vert
new file mode 100644
index 00000000..b2dfdd7b
--- /dev/null
+++ b/src/datavisualization/engine/shaders/point_ES2.vert
@@ -0,0 +1,8 @@
+uniform highp mat4 MVP;
+
+attribute highp vec3 vertexPosition_mdl;
+
+void main() {
+    gl_PointSize = 5.0;
+    gl_Position = MVP * vec4(vertexPosition_mdl, 1.0);
+}