Add support for paths.

Rendering is implementing by rasterizing the paths into A8 textures.
This cna be extremely inefficient if the path changes often.

Change-Id: I609343f304ae38e0d319359403ee73b9b5b3c93a

1 files changed, 165 insertions, 0 deletions

diff --git a/libs/hwui/PathCache.cpp b/libs/hwui/PathCache.cpp
new file mode 100644
index 000000000000..67a5f923d598
--- /dev/null
+++ b/libs/hwui/PathCache.cpp
@@ -0,0 +1,165 @@
+/*
+ * Copyright (C) 2010 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 <GLES2/gl2.h>
+
+#include <SkCanvas.h>
+#include <SkRect.h>
+
+#include "PathCache.h"
+
+namespace android {
+namespace uirenderer {
+
+///////////////////////////////////////////////////////////////////////////////
+// Constructors/destructor
+///////////////////////////////////////////////////////////////////////////////
+
+PathCache::PathCache(uint32_t maxByteSize):
+        mCache(GenerationCache<PathCacheEntry, PathTexture*>::kUnlimitedCapacity),
+        mSize(0), mMaxSize(maxByteSize) {
+    mCache.setOnEntryRemovedListener(this);
+}
+
+PathCache::~PathCache() {
+    mCache.clear();
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// Size management
+///////////////////////////////////////////////////////////////////////////////
+
+uint32_t PathCache::getSize() {
+    return mSize;
+}
+
+uint32_t PathCache::getMaxSize() {
+    return mMaxSize;
+}
+
+void PathCache::setMaxSize(uint32_t maxSize) {
+    mMaxSize = maxSize;
+    while (mSize > mMaxSize) {
+        mCache.removeOldest();
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// Callbacks
+///////////////////////////////////////////////////////////////////////////////
+
+void PathCache::operator()(PathCacheEntry& path, PathTexture*& texture) {
+    const uint32_t size = texture->width * texture->height;
+    mSize -= size;
+
+    if (texture) {
+        glDeleteTextures(1, &texture->id);
+        delete texture;
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// Caching
+///////////////////////////////////////////////////////////////////////////////
+
+PathTexture* PathCache::get(SkPath* path, SkPaint* paint) {
+    PathCacheEntry entry(path, paint);
+    PathTexture* texture = mCache.get(entry);
+
+    if (!texture) {
+        texture = addTexture(entry, path, paint);
+    } else if (path->getGenerationID() != texture->generation) {
+        mCache.remove(entry);
+        texture = addTexture(entry, path, paint);
+    }
+
+    // TODO: Do something to destroy the texture object if it's too big for the cache
+    return texture;
+}
+
+PathTexture* PathCache::addTexture(const PathCacheEntry& entry,
+        const SkPath *path, const SkPaint* paint) {
+    const SkRect& bounds = path->getBounds();
+    const float offset = entry.strokeWidth * 1.5f;
+    const uint32_t width = uint32_t(bounds.width() + offset * 2.0 + 0.5);
+    const uint32_t height = uint32_t(bounds.height() + offset * 2.0 + 0.5);
+
+    const uint32_t size = width * height;
+    // Don't even try to cache a bitmap that's bigger than the cache
+    if (size < mMaxSize) {
+        while (mSize + size > mMaxSize) {
+            mCache.removeOldest();
+        }
+    }
+
+    PathTexture* texture = new PathTexture;
+    texture->left = bounds.fLeft;
+    texture->top = bounds.fTop;
+    texture->offset = offset;
+    texture->width = width;
+    texture->height = height;
+    texture->generation = path->getGenerationID();
+
+    SkBitmap bitmap;
+    bitmap.setConfig(SkBitmap::kA8_Config, width, height);
+    bitmap.allocPixels();
+    bitmap.eraseColor(0);
+
+    SkCanvas canvas(bitmap);
+    canvas.translate(-bounds.fLeft + offset, -bounds.fTop + offset);
+    canvas.drawPath(*path, *paint);
+
+    generateTexture(bitmap, texture);
+
+    if (size < mMaxSize) {
+        mSize += size;
+        mCache.put(entry, texture);
+    }
+
+    return texture;
+}
+
+void PathCache::clear() {
+    mCache.clear();
+}
+
+void PathCache::generateTexture(SkBitmap& bitmap, Texture* texture) {
+    SkAutoLockPixels alp(bitmap);
+    if (!bitmap.readyToDraw()) {
+        LOGE("Cannot generate texture from bitmap");
+        return;
+    }
+
+    glGenTextures(1, &texture->id);
+
+    glBindTexture(GL_TEXTURE_2D, texture->id);
+    glPixelStorei(GL_UNPACK_ALIGNMENT, bitmap.bytesPerPixel());
+
+    texture->blend = true;
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, bitmap.rowBytesAsPixels(), texture->height, 0,
+            GL_ALPHA, GL_UNSIGNED_BYTE, bitmap.getPixels());
+
+    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);
+}
+
+}; // namespace uirenderer
+}; // namespace android