Better backend for hardware layers.

With this new backend, a hardware layer is only recreated when
its associated view is udpated. This offers fast composition
in GL and fast update of the layer in GL as well.

Change-Id: I97c43a612f5955c6bf1c192c8ca4af10fdf1d076

1 files changed, 121 insertions, 0 deletions

diff --git a/libs/hwui/LayerRenderer.cpp b/libs/hwui/LayerRenderer.cpp
new file mode 100644
index 000000000000..3583b8658254
--- /dev/null
+++ b/libs/hwui/LayerRenderer.cpp
@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "OpenGLRenderer"
+
+#include "LayerRenderer.h"
+
+namespace android {
+namespace uirenderer {
+
+///////////////////////////////////////////////////////////////////////////////
+// Rendering
+///////////////////////////////////////////////////////////////////////////////
+
+void LayerRenderer::prepare(bool opaque) {
+    glGetIntegerv(GL_FRAMEBUFFER_BINDING, (GLint*) &mPreviousFbo);
+    glBindFramebuffer(GL_FRAMEBUFFER, mFbo);
+    OpenGLRenderer::prepare(opaque);
+}
+
+void LayerRenderer::finish() {
+    OpenGLRenderer::finish();
+    glBindFramebuffer(GL_FRAMEBUFFER, mPreviousFbo);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// Static functions
+///////////////////////////////////////////////////////////////////////////////
+
+GLuint LayerRenderer::createLayer(uint32_t width, uint32_t height,
+        uint32_t* layerWidth, uint32_t* layerHeight, GLuint* texture) {
+    GLuint previousFbo;
+    glGetIntegerv(GL_FRAMEBUFFER_BINDING, (GLint*) &previousFbo);
+
+    GLuint fbo = 0;
+    glGenFramebuffers(1, &fbo);
+    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+
+    glActiveTexture(GL_TEXTURE0);
+    glGenTextures(1, texture);
+    glBindTexture(GL_TEXTURE_2D, *texture);
+
+    glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
+
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0,
+            GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+
+    if (glGetError() != GL_NO_ERROR) {
+        glDeleteBuffers(1, &fbo);
+        glDeleteTextures(1, texture);
+        glBindFramebuffer(GL_FRAMEBUFFER, previousFbo);
+        return 0;
+    }
+
+    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
+                *texture, 0);
+
+    if (glGetError() != GL_NO_ERROR) {
+        glDeleteBuffers(1, &fbo);
+        glDeleteTextures(1, texture);
+        glBindFramebuffer(GL_FRAMEBUFFER, previousFbo);
+        return 0;
+    }
+
+    glBindFramebuffer(GL_FRAMEBUFFER, previousFbo);
+
+    *layerWidth = width;
+    *layerHeight = height;
+
+    return fbo;
+}
+
+void LayerRenderer::resizeLayer(GLuint fbo, GLuint texture, uint32_t width, uint32_t height,
+        uint32_t* layerWidth, uint32_t* layerHeight) {
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_2D, texture);
+
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0,
+            GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+
+    if (glGetError() != GL_NO_ERROR) {
+        glDeleteBuffers(1, &fbo);
+        glDeleteTextures(1, texture);
+        glBindFramebuffer(GL_FRAMEBUFFER, previousFbo);
+
+        *layerWidth = 0;
+        *layerHeight = 0;
+
+        return;
+    }
+
+    *layerWidth = width;
+    *layerHeight = height;
+}
+
+void LayerRenderer::destroyLayer(GLuint fbo, GLuint texture) {
+    if (fbo) glDeleteFramebuffers(1, &fbo);
+    if (texture) glDeleteTextures(1, &texture);
+}
+
+}; // namespace uirenderer
+}; // namespace android