Define shadow casting behavior within layers

bug:15860114

Savelayers and HW layers both now support shadow casting.

For save layers, the light source should always be correct, for HW
layers, the light source position is set when the layer is created,
and updated when it is resized.

Change-Id: Ie85567dd43c2bb0a0b08fd0bd4db41efa793ac2b

1 files changed, 16 insertions, 2 deletions

diff --git a/libs/hwui/Layer.cpp b/libs/hwui/Layer.cpp
index d05cabca7b5a..8639ae1629e6 100644
--- a/libs/hwui/Layer.cpp
+++ b/libs/hwui/Layer.cpp
@@ -53,6 +53,7 @@ Layer::Layer(RenderState& renderState, const uint32_t layerWidth, const uint32_t
     deferredList = NULL;
     convexMask = NULL;
     caches.resourceCache.incrementRefcount(this);
+    rendererLightPosDirty = true;
 }
 
 Layer::~Layer() {
@@ -80,6 +81,17 @@ void Layer::requireRenderer() {
     }
 }
 
+void Layer::updateLightPosFromRenderer(const OpenGLRenderer& rootRenderer) {
+    if (renderer && rendererLightPosDirty) {
+        // re-init renderer's light position, based upon last cached location in window
+        Vector3 lightPos = rootRenderer.getLightCenter();
+        cachedInvTransformInWindow.mapPoint3d(lightPos);
+        renderer->initLight(lightPos, rootRenderer.getLightRadius(),
+                rootRenderer.getAmbientShadowAlpha(), rootRenderer.getSpotShadowAlpha());
+        rendererLightPosDirty = false;
+    }
+}
+
 bool Layer::resize(const uint32_t width, const uint32_t height) {
     uint32_t desiredWidth = computeIdealWidth(width);
     uint32_t desiredHeight = computeIdealWidth(height);
@@ -203,7 +215,8 @@ void Layer::allocateTexture() {
     }
 }
 
-void Layer::defer() {
+void Layer::defer(const OpenGLRenderer& rootRenderer) {
+    updateLightPosFromRenderer(rootRenderer);
     const float width = layer.getWidth();
     const float height = layer.getHeight();
 
@@ -253,7 +266,8 @@ void Layer::flush() {
     }
 }
 
-void Layer::render() {
+void Layer::render(const OpenGLRenderer& rootRenderer) {
+    updateLightPosFromRenderer(rootRenderer);
     renderer->setViewport(layer.getWidth(), layer.getHeight());
     renderer->prepareDirty(dirtyRect.left, dirtyRect.top, dirtyRect.right, dirtyRect.bottom,
             !isBlend());