Revert "Revert "Use renderengine::drawLayers api everywhere.""

This reverts commit 79108df863d454369ee61cdb70f6d14c8414e30e.

Reason for revert: merged in forward fix - GL_BLEND is now explictly
disabled before initially clearing the buffer.

Bug: 118461793
Test: b/123878751 cannot be reproduced.
Change-Id: Ia49163b40016e746500d9954e1863d0706bc65e1
diff --git a/services/surfaceflinger/BufferLayer.cpp b/services/surfaceflinger/BufferLayer.cpp
index 65308a6..f986329 100644
--- a/services/surfaceflinger/BufferLayer.cpp
+++ b/services/surfaceflinger/BufferLayer.cpp
@@ -57,8 +57,6 @@
                 compositionengine::LayerCreationArgs{this})} {
     ALOGV("Creating Layer %s", args.name.string());
 
-    mTexture.init(renderengine::Texture::TEXTURE_EXTERNAL, mTextureName);
-
     mPremultipliedAlpha = !(args.flags & ISurfaceComposerClient::eNonPremultiplied);
 
     mPotentialCursor = args.flags & ISurfaceComposerClient::eCursorWindow;
@@ -129,13 +127,11 @@
     return inverse(tr);
 }
 
-/*
- * onDraw will draw the current layer onto the presentable buffer
- */
-void BufferLayer::onDraw(const RenderArea& renderArea, const Region& clip,
-                         bool useIdentityTransform) {
+bool BufferLayer::prepareClientLayer(const RenderArea& renderArea, const Region& clip,
+                                     bool useIdentityTransform, Region& clearRegion,
+                                     renderengine::LayerSettings& layer) {
     ATRACE_CALL();
-
+    Layer::prepareClientLayer(renderArea, clip, useIdentityTransform, clearRegion, layer);
     if (CC_UNLIKELY(mActiveBuffer == 0)) {
         // the texture has not been created yet, this Layer has
         // in fact never been drawn into. This happens frequently with
@@ -153,30 +149,27 @@
                 finished = true;
                 return;
             }
-            under.orSelf(renderArea.getTransform().transform(layer->visibleRegion));
+            under.orSelf(layer->visibleRegion);
         });
         // if not everything below us is covered, we plug the holes!
         Region holes(clip.subtract(under));
         if (!holes.isEmpty()) {
-            clearWithOpenGL(renderArea, 0, 0, 0, 1);
+            clearRegion.orSelf(holes);
         }
-        return;
+        return false;
     }
-
-    // Bind the current buffer to the GL texture, and wait for it to be
-    // ready for us to draw into.
-    status_t err = bindTextureImage();
-    if (err != NO_ERROR) {
-        ALOGW("onDraw: bindTextureImage failed (err=%d)", err);
-        // Go ahead and draw the buffer anyway; no matter what we do the screen
-        // is probably going to have something visibly wrong.
-    }
-
     bool blackOutLayer = isProtected() || (isSecure() && !renderArea.isSecure());
-
-    auto& engine(mFlinger->getRenderEngine());
-
+    const State& s(getDrawingState());
     if (!blackOutLayer) {
+        layer.source.buffer.buffer = mActiveBuffer;
+        layer.source.buffer.isOpaque = isOpaque(s);
+        layer.source.buffer.fence = mActiveBufferFence;
+        layer.source.buffer.cacheHint = useCachedBufferForClientComposition()
+                ? renderengine::Buffer::CachingHint::USE_CACHE
+                : renderengine::Buffer::CachingHint::NO_CACHE;
+        layer.source.buffer.textureName = mTextureName;
+        layer.source.buffer.usePremultipliedAlpha = getPremultipledAlpha();
+        layer.source.buffer.isY410BT2020 = isHdrY410();
         // TODO: we could be more subtle with isFixedSize()
         const bool useFiltering = needsFiltering() || renderArea.needsFiltering() || isFixedSize();
 
@@ -213,17 +206,31 @@
             memcpy(textureMatrix, texTransform.asArray(), sizeof(textureMatrix));
         }
 
-        // Set things up for texturing.
-        mTexture.setDimensions(mActiveBuffer->getWidth(), mActiveBuffer->getHeight());
-        mTexture.setFiltering(useFiltering);
-        mTexture.setMatrix(textureMatrix);
+        const Rect win{computeBounds()};
+        const float bufferWidth = getBufferSize(s).getWidth();
+        const float bufferHeight = getBufferSize(s).getHeight();
 
-        engine.setupLayerTexturing(mTexture);
+        const float scaleHeight = (float(win.bottom) - float(win.top)) / bufferHeight;
+        const float scaleWidth = (float(win.right) - float(win.left)) / bufferWidth;
+        const float translateY = float(win.top) / bufferHeight;
+        const float translateX = float(win.left) / bufferWidth;
+
+        // Flip y-coordinates because GLConsumer expects OpenGL convention.
+        mat4 tr = mat4::translate(vec4(.5, .5, 0, 1)) * mat4::scale(vec4(1, -1, 1, 1)) *
+                mat4::translate(vec4(-.5, -.5, 0, 1)) *
+                mat4::translate(vec4(translateX, translateY, 0, 1)) *
+                mat4::scale(vec4(scaleWidth, scaleHeight, 1.0, 1.0));
+
+        layer.source.buffer.useTextureFiltering = useFiltering;
+        layer.source.buffer.textureTransform = mat4(static_cast<const float*>(textureMatrix)) * tr;
     } else {
-        engine.setupLayerBlackedOut();
+        // If layer is blacked out, force alpha to 1 so that we draw a black color
+        // layer.
+        layer.source.buffer.buffer = nullptr;
+        layer.alpha = 1.0;
     }
-    drawWithOpenGL(renderArea, useIdentityTransform);
-    engine.disableTexturing();
+
+    return true;
 }
 
 bool BufferLayer::isHdrY410() const {
@@ -606,67 +613,6 @@
             sourceCrop.getWidth() != displayFrame.getWidth();
 }
 
-void BufferLayer::drawWithOpenGL(const RenderArea& renderArea, bool useIdentityTransform) const {
-    ATRACE_CALL();
-    const State& s(getDrawingState());
-
-    computeGeometry(renderArea, getBE().mMesh, useIdentityTransform);
-
-    /*
-     * NOTE: the way we compute the texture coordinates here produces
-     * different results than when we take the HWC path -- in the later case
-     * the "source crop" is rounded to texel boundaries.
-     * This can produce significantly different results when the texture
-     * is scaled by a large amount.
-     *
-     * The GL code below is more logical (imho), and the difference with
-     * HWC is due to a limitation of the HWC API to integers -- a question
-     * is suspend is whether we should ignore this problem or revert to
-     * GL composition when a buffer scaling is applied (maybe with some
-     * minimal value)? Or, we could make GL behave like HWC -- but this feel
-     * like more of a hack.
-     */
-    const Rect bounds{computeBounds()}; // Rounds from FloatRect
-
-    Rect win = bounds;
-    const int bufferWidth = getBufferSize(s).getWidth();
-    const int bufferHeight = getBufferSize(s).getHeight();
-
-    const float left = float(win.left) / float(bufferWidth);
-    const float top = float(win.top) / float(bufferHeight);
-    const float right = float(win.right) / float(bufferWidth);
-    const float bottom = float(win.bottom) / float(bufferHeight);
-
-    // TODO: we probably want to generate the texture coords with the mesh
-    // here we assume that we only have 4 vertices
-    renderengine::Mesh::VertexArray<vec2> texCoords(getBE().mMesh.getTexCoordArray<vec2>());
-    // flip texcoords vertically because BufferLayerConsumer expects them to be in GL convention
-    texCoords[0] = vec2(left, 1.0f - top);
-    texCoords[1] = vec2(left, 1.0f - bottom);
-    texCoords[2] = vec2(right, 1.0f - bottom);
-    texCoords[3] = vec2(right, 1.0f - top);
-
-    const auto roundedCornerState = getRoundedCornerState();
-    const auto cropRect = roundedCornerState.cropRect;
-    setupRoundedCornersCropCoordinates(win, cropRect);
-
-    auto& engine(mFlinger->getRenderEngine());
-    engine.setupLayerBlending(mPremultipliedAlpha, isOpaque(s), false /* disableTexture */,
-                              getColor(), roundedCornerState.radius);
-    engine.setSourceDataSpace(mCurrentDataSpace);
-
-    if (isHdrY410()) {
-        engine.setSourceY410BT2020(true);
-    }
-
-    engine.setupCornerRadiusCropSize(cropRect.getWidth(), cropRect.getHeight());
-
-    engine.drawMesh(getBE().mMesh);
-    engine.disableBlending();
-
-    engine.setSourceY410BT2020(false);
-}
-
 uint64_t BufferLayer::getHeadFrameNumber() const {
     if (hasFrameUpdate()) {
         return getFrameNumber();