// Note: These MUST be in the same order as Dali::StencilOperation enum.
const int DaliStencilOperationToGL[] = { GL_ZERO, GL_KEEP, GL_REPLACE, GL_INCR, GL_DECR, GL_INVERT, GL_INCR_WRAP, GL_DECR_WRAP };
-} // Unnamed namespace
-
/**
- * Sets up the scissor test if required.
- * @param[in] renderList The render list from which to get the clipping flag
- * @param[in] context The context
+ * @brief Find the intersection of two AABB rectangles.
+ * This is a logical AND operation. IE. The intersection is the area overlapped by both rectangles.
+ * @param[in] aabbA Rectangle A
+ * @param[in] aabbB Rectangle B
+ * @return The intersection of rectangle A & B (result is a rectangle)
*/
-inline void SetScissorTest( const RenderList& renderList, Context& context )
+inline ClippingBox IntersectAABB( const ClippingBox& aabbA, const ClippingBox& aabbB )
{
- // Scissor testing
- if( renderList.IsClipping() )
- {
- context.SetScissorTest( true );
+ ClippingBox intersectionBox;
- const Dali::ClippingBox& clip = renderList.GetClippingBox();
- context.Scissor( clip.x, clip.y, clip.width, clip.height );
- }
- else
- {
- context.SetScissorTest( false );
- }
+ // First calculate the largest starting positions in X and Y.
+ intersectionBox.x = std::max( aabbA.x, aabbB.x );
+ intersectionBox.y = std::max( aabbA.y, aabbB.y );
+
+ // Now calculate the smallest ending positions, and take the largest starting
+ // positions from the result, to get the width and height respectively.
+ // If the two boxes do not intersect at all, then we need a 0 width and height clipping area.
+ // We use max here to clamp both width and height to >= 0 for this use-case.
+ intersectionBox.width = std::max( std::min( aabbA.x + aabbA.width, aabbB.x + aabbB.width ) - intersectionBox.x, 0 );
+ intersectionBox.height = std::max( std::min( aabbA.y + aabbA.height, aabbB.y + aabbB.height ) - intersectionBox.y, 0 );
+
+ return intersectionBox;
}
/**
* @brief Set up the stencil and color buffer for automatic clipping (StencilMode::AUTO).
* @param[in] item The current RenderItem about to be rendered
* @param[in] context The context
- * @param[in/out] lastStencilDepth The stencil depth of the last renderer drawn.
+ * @param[in/out] lastClippingDepth The stencil depth of the last renderer drawn.
* @param[in/out] lastClippingId The clipping ID of the last renderer drawn.
*/
-inline void SetupClipping( const RenderItem& item, Context& context, uint32_t& lastStencilDepth, uint32_t& lastClippingId )
+inline void SetupStencilClipping( const RenderItem& item, Context& context, uint32_t& lastClippingDepth, uint32_t& lastClippingId )
{
const Dali::Internal::SceneGraph::Node* node = item.mNode;
const uint32_t clippingId = node->GetClippingId();
-
- // Turn the color buffer on as we always want to render this renderer, regardless of clipping hierarchy.
- context.ColorMask( true );
-
// If there is no clipping Id, then either we haven't reached a clipping Node yet, or there aren't any.
// Either way we can skip clipping setup for this renderer.
if( clippingId == 0u )
return;
}
- const ClippingMode::Type clippingMode( node->GetClippingMode() );
- const uint32_t currentStencilDepth( node->GetClippingDepth() );
-
context.EnableStencilBuffer( true );
+ const uint32_t clippingDepth = node->GetClippingDepth();
+
// Pre-calculate a mask which has all bits set up to and including the current clipping depth.
// EG. If depth is 3, the mask would be "111" in binary.
- const uint32_t currentDepthMask = ( 1u << currentStencilDepth ) - 1u;
+ const uint32_t currentDepthMask = ( 1u << clippingDepth ) - 1u;
- // If we have a clipping mode specified, we are writing to the stencil buffer.
- if( clippingMode != ClippingMode::DISABLED )
+ // Are we are writing to the stencil buffer?
+ if( item.mNode->GetClippingMode() == Dali::ClippingMode::CLIP_CHILDREN )
{
// We are writing to the stencil buffer.
// If clipping Id is 1, this is the first clipping renderer within this render-list.
context.StencilMask( 0xff );
context.Clear( GL_STENCIL_BUFFER_BIT, Context::CHECK_CACHED_VALUES );
}
- else if( ( currentStencilDepth < lastStencilDepth ) ||
- ( ( currentStencilDepth == lastStencilDepth ) && ( clippingId > lastClippingId ) ) )
+ else if( ( clippingDepth < lastClippingDepth ) ||
+ ( ( clippingDepth == lastClippingDepth ) && ( clippingId > lastClippingId ) ) )
{
// The above if() statement tests if we need to clear some (not all) stencil bit-planes.
// We need to do this if either of the following are true:
// We keep track of the last clipping Id and depth so we can determine when we are
// moving back up the scene graph and require some of the stencil bit-planes to be deleted.
- lastStencilDepth = currentStencilDepth;
+ lastClippingDepth = clippingDepth;
lastClippingId = clippingId;
// We only ever write to bit-planes up to the current depth as we may need
}
/**
- * @brief Set up the stencil and color buffer based on the current Renderers properties.
+ * @brief Sets up the depth buffer for reading and writing based on the current render item.
+ * The items read and write mode are used if specified.
+ * - If AUTO is selected for reading, the decision will be based on the Layer Behavior.
+ * - If AUTO is selected for writing, the decision will be based on the items opacity.
+ * @param[in] item The RenderItem to set up the depth buffer for.
+ * @param[in] context The context used to execute GL commands.
+ * @param[in] depthTestEnabled True if depth testing has been enabled.
+ * @param[in/out] firstDepthBufferUse Initialize to true on the first call, this method will set it to false afterwards.
+ */
+inline void SetupDepthBuffer( const RenderItem& item, Context& context, bool depthTestEnabled, bool& firstDepthBufferUse )
+{
+ // Set up whether or not to write to the depth buffer.
+ const DepthWriteMode::Type depthWriteMode = item.mRenderer->GetDepthWriteMode();
+ // Most common mode (AUTO) is tested first.
+ const bool enableDepthWrite = ( ( depthWriteMode == DepthWriteMode::AUTO ) && depthTestEnabled && item.mIsOpaque ) ||
+ ( depthWriteMode == DepthWriteMode::ON );
+
+ // Set up whether or not to read from (test) the depth buffer.
+ const DepthTestMode::Type depthTestMode = item.mRenderer->GetDepthTestMode();
+ // Most common mode (AUTO) is tested first.
+ const bool enableDepthTest = ( ( depthTestMode == DepthTestMode::AUTO ) && depthTestEnabled ) ||
+ ( depthTestMode == DepthTestMode::ON );
+
+ // Is the depth buffer in use?
+ if( enableDepthWrite || enableDepthTest )
+ {
+ // The depth buffer must be enabled if either reading or writing.
+ context.EnableDepthBuffer( true );
+
+ // Set up the depth mask based on our depth write setting.
+ context.DepthMask( enableDepthWrite );
+
+ // Look-up the GL depth function from the Dali::DepthFunction enum, and set it.
+ context.DepthFunc( DaliDepthToGLDepthTable[ item.mRenderer->GetDepthFunction() ] );
+
+ // If this is the first use of the depth buffer this RenderTask, perform a clear.
+ // Note: We could do this at the beginning of the RenderTask and rely on the
+ // context cache to ignore the clear if not required, but, we would have to enable
+ // the depth buffer to do so, which could be a redundant enable.
+ if( DALI_UNLIKELY( firstDepthBufferUse ) )
+ {
+ // This is the first time the depth buffer is being written to or read.
+ firstDepthBufferUse = false;
+
+ // Note: The buffer will only be cleared if written to since a previous clear.
+ context.Clear( GL_DEPTH_BUFFER_BIT, Context::CHECK_CACHED_VALUES );
+ }
+ }
+ else
+ {
+ // The depth buffer is not being used by this renderer, so we must disable it to stop it being tested.
+ context.EnableDepthBuffer( false );
+ }
+}
+
+} // Unnamed namespace
+
+
+/**
+ * @brief This method is responsible for making decisions on when to apply and unapply scissor clipping, and what rectangular dimensions should be used.
+ * A stack of scissor clips at each depth of clipping is maintained, so it can be applied and unapplied.
+ * As the clips are hierarchical, this RenderItems AABB is clipped against the current "active" scissor bounds via an intersection operation.
* @param[in] item The current RenderItem about to be rendered
* @param[in] context The context
- * @param[in/out] usedStencilBuffer True if the stencil buffer has been used so far within this RenderList. Used by StencilMode::ON.
- * @param[in/out] lastStencilDepth The stencil depth of the last renderer drawn. Used by the clipping feature.
- * @param[in/out] lastClippingId The clipping ID of the last renderer drawn. Used by the clipping feature.
*/
-inline void SetupStencilBuffer( const RenderItem& item, Context& context, bool& usedStencilBuffer, uint32_t& lastStencilDepth, uint32_t& lastClippingId )
+inline void RenderAlgorithms::SetupScissorClipping( const RenderItem& item, Context& context )
+{
+ // Get the number of child scissors in the stack (do not include layer or root box).
+ size_t childStackDepth = mScissorStack.size() - 1u;
+ const uint32_t scissorDepth = item.mNode->GetScissorDepth();
+ const bool clippingNode = item.mNode->GetClippingMode() == Dali::ClippingMode::CLIP_TO_BOUNDING_BOX;
+ bool traversedUpTree = false;
+
+ // If we are using scissor clipping and we are at the same depth (or less), we need to undo previous clips.
+ // We do this by traversing up the scissor clip stack and then apply the appropriate clip for the current render item.
+ // To know this, we use clippingDepth. This value is set on *every* node, but only increased as clipping nodes are hit depth-wise.
+ // So we know if we are at depth 4 and the stackDepth is 5, that we have gone up.
+ // If the depth is the same then we are effectively part of a different sub-tree from the parent, we must also remove the current clip.
+ // Note: Stack depth must always be at least 1, as we will have the layer or stage size as the root value.
+ if( ( childStackDepth > 0u ) && ( scissorDepth < childStackDepth ) )
+ {
+ while( scissorDepth < childStackDepth )
+ {
+ mScissorStack.pop_back();
+ --childStackDepth;
+ }
+
+ // We traversed up the tree, we need to apply a new scissor rectangle (unless we are at the root).
+ traversedUpTree = true;
+ }
+ else if( clippingNode && childStackDepth > 0u && childStackDepth == scissorDepth ) // case of sibling clip area
+ {
+ mScissorStack.pop_back();
+ }
+
+ // If we are on a clipping node, or we have traveled up the tree and gone back past a clipping node, may need to apply a new scissor clip.
+ if( clippingNode || traversedUpTree )
+ {
+ // First, check if we are a clipping node.
+ if( clippingNode )
+ {
+ // This is a clipping node. We generate the AABB for this node and intersect it with the previous intersection further up the tree.
+
+ // Get the AABB bounding box for the current render item.
+ const ClippingBox scissorBox( item.CalculateViewportSpaceAABB( mViewportRectangle.width, mViewportRectangle.height ) );
+
+ // Get the AABB for the parent item that we must intersect with.
+ const ClippingBox& parentBox( mScissorStack.back() );
+
+ // We must reduce the clipping area based on the parents area to allow nested clips. This is a set intersection function.
+ // We add the new scissor box to the stack so we can return to it if needed.
+ mScissorStack.emplace_back( IntersectAABB( parentBox, scissorBox ) );
+ }
+
+ // The scissor test is enabled if we have any children on the stack, OR, if there are none but it is a user specified layer scissor box.
+ // IE. It is not enabled if we are at the top of the stack and the layer does not have a specified clipping box.
+ const bool scissorEnabled = ( mScissorStack.size() > 0u ) || mHasLayerScissor;
+
+ // Enable the scissor test based on the above calculation
+ context.SetScissorTest( scissorEnabled );
+
+ // If scissor is enabled, we use the calculated screen-space coordinates (now in the stack).
+ if( scissorEnabled )
+ {
+ ClippingBox useScissorBox( mScissorStack.back() );
+ context.Scissor( useScissorBox.x, useScissorBox.y, useScissorBox.width, useScissorBox.height );
+ }
+ }
+}
+
+inline void RenderAlgorithms::SetupClipping( const RenderItem& item, Context& context, bool& usedStencilBuffer, uint32_t& lastClippingDepth, uint32_t& lastClippingId )
{
+ RenderMode::Type renderMode = RenderMode::AUTO;
const Renderer *renderer = item.mRenderer;
+ if( renderer )
+ {
+ renderMode = renderer->GetRenderMode();
+ }
// Setup the stencil using either the automatic clipping feature, or, the manual per-renderer stencil API.
// Note: This switch is in order of most likely value first.
- RenderMode::Type renderMode = renderer->GetRenderMode();
switch( renderMode )
{
case RenderMode::AUTO:
{
- // The automatic clipping feature will manage the stencil functions and color buffer mask.
- SetupClipping( item, context, lastStencilDepth, lastClippingId );
+ // Turn the color buffer on as we always want to render this renderer, regardless of clipping hierarchy.
+ context.ColorMask( true );
+
+ // The automatic clipping feature will manage the scissor and stencil functions.
+ // As both scissor and stencil clips can be nested, we may be simultaneously traversing up the scissor tree, requiring a scissor to be un-done. Whilst simultaneously adding a new stencil clip.
+ // We process both based on our current and old clipping depths for each mode.
+ // Both methods with return rapidly if there is nothing to be done for that type of clipping.
+ SetupScissorClipping( item, context );
+ SetupStencilClipping( item, context, lastClippingDepth, lastClippingId );
break;
}
case RenderMode::NONE:
case RenderMode::COLOR:
{
+ // No clipping is performed for these modes.
+ // Note: We do not turn off scissor clipping as it may be used for the whole layer.
// The stencil buffer will not be used at all.
context.EnableStencilBuffer( false );
}
}
-/**
- * @brief Sets up the depth buffer for reading and writing based on the current render item.
- * The items read and write mode are used if specified.
- * - If AUTO is selected for reading, the decision will be based on the Layer Behavior.
- * - If AUTO is selected for writing, the decision will be based on the items opacity.
- * @param[in] item The RenderItem to set up the depth buffer for.
- * @param[in] context The context used to execute GL commands.
- * @param[in] depthTestEnabled True if depth testing has been enabled.
- * @param[in/out] firstDepthBufferUse Initialise to true on the first call, this method will set it to false afterwards.
- */
-inline void SetupDepthBuffer( const RenderItem& item, Context& context, bool depthTestEnabled, bool& firstDepthBufferUse )
-{
- // Set up whether or not to write to the depth buffer.
- const DepthWriteMode::Type depthWriteMode = item.mRenderer->GetDepthWriteMode();
- // Most common mode (AUTO) is tested first.
- const bool enableDepthWrite = ( ( depthWriteMode == DepthWriteMode::AUTO ) && depthTestEnabled && item.mIsOpaque ) ||
- ( depthWriteMode == DepthWriteMode::ON );
-
- // Set up whether or not to read from (test) the depth buffer.
- const DepthTestMode::Type depthTestMode = item.mRenderer->GetDepthTestMode();
- // Most common mode (AUTO) is tested first.
- const bool enableDepthTest = ( ( depthTestMode == DepthTestMode::AUTO ) && depthTestEnabled ) ||
- ( depthTestMode == DepthTestMode::ON );
-
- // Is the depth buffer in use?
- if( enableDepthWrite || enableDepthTest )
- {
- // The depth buffer must be enabled if either reading or writing.
- context.EnableDepthBuffer( true );
-
- // Set up the depth mask based on our depth write setting.
- context.DepthMask( enableDepthWrite );
-
- // Look-up the GL depth function from the Dali::DepthFunction enum, and set it.
- context.DepthFunc( DaliDepthToGLDepthTable[ item.mRenderer->GetDepthFunction() ] );
-
- // If this is the first use of the depth buffer this RenderTask, perform a clear.
- // Note: We could do this at the beginning of the RenderTask and rely on the
- // context cache to ignore the clear if not required, but, we would have to enable
- // the depth buffer to do so, which could be a redundant enable.
- if( DALI_UNLIKELY( firstDepthBufferUse ) )
- {
- // This is the first time the depth buffer is being written to or read.
- firstDepthBufferUse = false;
-
- // Note: The buffer will only be cleared if written to since a previous clear.
- context.Clear( GL_DEPTH_BUFFER_BIT, Context::CHECK_CACHED_VALUES );
- }
- }
- else
- {
- // The depth buffer is not being used by this renderer, so we must disable it to stop it being tested.
- context.EnableDepthBuffer( false );
- }
-}
-
-/**
- * @brief Process a render-list.
- * @param[in] renderList The render-list to process.
- * @param[in] context The GL context.
- * @param[in] buffer The current render buffer index (previous update buffer)
- * @param[in] viewMatrix The view matrix from the appropriate camera.
- * @param[in] projectionMatrix The projection matrix from the appropriate camera.
- */
-inline void ProcessRenderList(
- const RenderList& renderList,
- Context& context,
- BufferIndex bufferIndex,
- const Matrix& viewMatrix,
- const Matrix& projectionMatrix )
+inline void RenderAlgorithms::ProcessRenderList( const RenderList& renderList,
+ Context& context,
+ BufferIndex bufferIndex,
+ const Matrix& viewMatrix,
+ const Matrix& projectionMatrix )
{
DALI_PRINT_RENDER_LIST( renderList );
- SetScissorTest( renderList, context );
-
// Note: The depth buffer is enabled or disabled on a per-renderer basis.
// Here we pre-calculate the value to use if these modes are set to AUTO.
const bool autoDepthTestMode( !( renderList.GetSourceLayer()->IsDepthTestDisabled() ) && renderList.HasColorRenderItems() );
const std::size_t count = renderList.Count();
- uint32_t lastStencilDepth( 0u );
+ uint32_t lastClippingDepth( 0u );
uint32_t lastClippingId( 0u );
bool usedStencilBuffer( false );
bool firstDepthBufferUse( true );
+ mViewportRectangle = context.GetViewport();
+ mHasLayerScissor = false;
+ // Setup Scissor testing (for both viewport and per-node scissor)
+ mScissorStack.clear();
+ if( renderList.IsClipping() )
+ {
+ context.SetScissorTest( true );
+ const ClippingBox& layerScissorBox = renderList.GetClippingBox();
+ context.Scissor( layerScissorBox.x, layerScissorBox.y, layerScissorBox.width, layerScissorBox.height );
+ mScissorStack.push_back( layerScissorBox );
+ mHasLayerScissor = true;
+ }
+ else
+ {
+ // We are not performing a layer clip. Add the viewport as the root scissor rectangle.
+ context.SetScissorTest( false );
+ mScissorStack.push_back( mViewportRectangle );
+ }
+
+ // Loop through all RenderList in the RenderList, set up any prerequisites to render them, then perform the render.
for( size_t index( 0u ); index < count; ++index )
{
const RenderItem& item = renderList.GetItem( index );
DALI_PRINT_RENDER_ITEM( item );
- // Set up the depth buffer based on per-renderer flags.
- // If the per renderer flags are set to "ON" or "OFF", they will always override any Layer depth mode or
- // draw-mode state, such as Overlays.
- // If the flags are set to "AUTO", the behaviour then depends on the type of renderer. Overlay Renderers will always
- // disable depth testing and writing. Color Renderers will enable them if the Layer does.
- SetupDepthBuffer( item, context, autoDepthTestMode, firstDepthBufferUse );
-
- // Set up the stencil buffer based on both the Renderer and Actor APIs.
+ // Set up clipping based on both the Renderer and Actor APIs.
// The Renderer API will be used if specified. If AUTO, the Actors automatic clipping feature will be used.
- SetupStencilBuffer( item, context, usedStencilBuffer, lastStencilDepth, lastClippingId );
-
- // Render the item
- item.mRenderer->Render( context,
- bufferIndex,
- *item.mNode,
- item.mModelMatrix,
- item.mModelViewMatrix,
- viewMatrix,
- projectionMatrix,
- item.mSize,
- !item.mIsOpaque );
+ SetupClipping( item, context, usedStencilBuffer, lastClippingDepth, lastClippingId );
+
+ if( DALI_LIKELY( item.mRenderer ) )
+ {
+ // Set up the depth buffer based on per-renderer flags.
+ // If the per renderer flags are set to "ON" or "OFF", they will always override any Layer depth mode or
+ // draw-mode state, such as Overlays.
+ // If the flags are set to "AUTO", the behavior then depends on the type of renderer. Overlay Renderers will always
+ // disable depth testing and writing. Color Renderers will enable them if the Layer does.
+ SetupDepthBuffer( item, context, autoDepthTestMode, firstDepthBufferUse );
+
+ // Render the item.
+ item.mRenderer->Render( context, bufferIndex, *item.mNode, item.mModelMatrix, item.mModelViewMatrix,
+ viewMatrix, projectionMatrix, item.mSize, !item.mIsOpaque );
+ }
}
}
-void ProcessRenderInstruction( const RenderInstruction& instruction,
- Context& context,
- BufferIndex bufferIndex )
+RenderAlgorithms::RenderAlgorithms()
+ : mViewportRectangle(),
+ mHasLayerScissor( false )
+{
+}
+
+void RenderAlgorithms::ProcessRenderInstruction( const RenderInstruction& instruction, Context& context, BufferIndex bufferIndex )
{
DALI_PRINT_RENDER_INSTRUCTION( instruction, bufferIndex );
if( renderList && !renderList->IsEmpty() )
{
- ProcessRenderList( *renderList,
- context,
- bufferIndex,
- *viewMatrix,
- *projectionMatrix );
+ ProcessRenderList( *renderList, context, bufferIndex, *viewMatrix, *projectionMatrix );
}
}
}
}
+
} // namespace Render
} // namespace Internal