GLFunctorDrawable.cpp revision 021693b967a2c5556dddd183eb0247df4079e1ad 
1/*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "GLFunctorDrawable.h"
18#include "GlFunctorLifecycleListener.h"
19#include "RenderNode.h"
20#include "SkClipStack.h"
21#include <private/hwui/DrawGlInfo.h>
22#include <SkPath.h>
23#include <GrContext.h>
24
25namespace android {
26namespace uirenderer {
27namespace skiapipeline {
28
29GLFunctorDrawable::~GLFunctorDrawable() {
30    if(mListener.get() != nullptr) {
31        mListener->onGlFunctorReleased(mFunctor);
32    }
33}
34
35void GLFunctorDrawable::syncFunctor() const {
36    (*mFunctor)(DrawGlInfo::kModeSync, nullptr);
37}
38
39static void setScissor(int viewportHeight, const SkIRect& clip) {
40    SkASSERT(!clip.isEmpty());
41    // transform to Y-flipped GL space, and prevent negatives
42    GLint y = viewportHeight - clip.fBottom;
43    GLint height = (viewportHeight - clip.fTop) - y;
44    glScissor(clip.fLeft, y, clip.width(), height);
45}
46
47void GLFunctorDrawable::onDraw(SkCanvas* canvas) {
48    if (canvas->getGrContext() == nullptr) {
49        SkDEBUGF(("Attempting to draw GLFunctor into an unsupported surface"));
50        return;
51    }
52
53    canvas->flush();
54
55    SkImageInfo canvasInfo = canvas->imageInfo();
56    SkMatrix44 mat4(canvas->getTotalMatrix());
57
58    SkIRect ibounds;
59    canvas->getClipDeviceBounds(&ibounds);
60
61    DrawGlInfo info;
62    info.clipLeft = ibounds.fLeft;
63    info.clipTop = ibounds.fTop;
64    info.clipRight = ibounds.fRight;
65    info.clipBottom = ibounds.fBottom;
66    //   info.isLayer = hasLayer();
67    info.isLayer = false;
68    info.width = canvasInfo.width();
69    info.height = canvasInfo.height();
70    mat4.asColMajorf(&info.transform[0]);
71
72    //apply a simple clip with a scissor or a complex clip with a stencil
73    SkRegion clipRegion;
74    SkPath path;
75    canvas->getClipStack()->asPath(&path);
76    clipRegion.setPath(path, SkRegion(ibounds));
77    if (CC_UNLIKELY(clipRegion.isComplex())) {
78        //It is only a temporary solution to use a scissor to draw the stencil.
79        //There is a bug 31489986 to implement efficiently non-rectangular clips.
80        glDisable(GL_SCISSOR_TEST);
81        glDisable(GL_STENCIL_TEST);
82        glStencilMask(0xff);
83        glClearStencil(0);
84        glClear(GL_STENCIL_BUFFER_BIT);
85        glEnable(GL_SCISSOR_TEST);
86        SkRegion::Cliperator it(clipRegion, ibounds);
87        while (!it.done()) {
88            setScissor(info.height, it.rect());
89            glClearStencil(0x1);
90            glClear(GL_STENCIL_BUFFER_BIT);
91            it.next();
92        }
93        glDisable(GL_SCISSOR_TEST);
94        glStencilFunc(GL_EQUAL, 0x1, 0xff);
95        glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
96        glEnable(GL_STENCIL_TEST);
97    } else if (clipRegion.isEmpty()) {
98        glDisable(GL_STENCIL_TEST);
99        glDisable(GL_SCISSOR_TEST);
100    } else {
101        glDisable(GL_STENCIL_TEST);
102        glEnable(GL_SCISSOR_TEST);
103        setScissor(info.height, clipRegion.getBounds());
104    }
105
106    (*mFunctor)(DrawGlInfo::kModeDraw, &info);
107
108    canvas->getGrContext()->resetContext();
109 }
110
111}; // namespace skiapipeline
112}; // namespace uirenderer
113}; // namespace android
114