/*
* 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.
*/
#ifndef ANDROID_HWUI_SNAPSHOT_H
#define ANDROID_HWUI_SNAPSHOT_H
#include <GLES2/gl2.h>
#include <GLES2/gl2ext.h>
#include <utils/RefBase.h>
#include <ui/Region.h>
#include <SkCanvas.h>
#include "Layer.h"
#include "Matrix.h"
#include "Rect.h"
namespace android {
namespace uirenderer {
/**
* A snapshot holds information about the current state of the rendering
* surface. A snapshot is usually created whenever the user calls save()
* and discarded when the user calls restore(). Once a snapshot is created,
* it can hold information for deferred rendering.
*
* Each snapshot has a link to a previous snapshot, indicating the previous
* state of the renderer.
*/
class Snapshot: public LightRefBase<Snapshot> {
public:
Snapshot(): flags(0), previous(NULL), layer(NULL), fbo(0), invisible(false), empty(false) {
transform = &mTransformRoot;
clipRect = &mClipRectRoot;
region = NULL;
}
/**
* Copies the specified snapshot/ The specified snapshot is stored as
* the previous snapshot.
*/
Snapshot(const sp<Snapshot>& s, int saveFlags):
flags(0), previous(s), layer(NULL), fbo(s->fbo),
invisible(s->invisible), empty(false), viewport(s->viewport), height(s->height) {
if (saveFlags & SkCanvas::kMatrix_SaveFlag) {
mTransformRoot.load(*s->transform);
transform = &mTransformRoot;
} else {
transform = s->transform;
}
if (saveFlags & SkCanvas::kClip_SaveFlag) {
mClipRectRoot.set(*s->clipRect);
clipRect = &mClipRectRoot;
} else {
clipRect = s->clipRect;
}
if (s->flags & Snapshot::kFlagFboTarget) {
flags |= Snapshot::kFlagFboTarget;
region = s->region;
} else {
region = NULL;
}
}
/**
* Various flags set on #flags.
*/
enum Flags {
/**
* Indicates that the clip region was modified. When this
* snapshot is restored so must the clip.
*/
kFlagClipSet = 0x1,
/**
* Indicates that this snapshot was created when saving
* a new layer.
*/
kFlagIsLayer = 0x2,
/**
* Indicates that this snapshot is a special type of layer
* backed by an FBO. This flag only makes sense when the
* flag kFlagIsLayer is also set.
*/
kFlagIsFboLayer = 0x4,
/**
* Indicates that this snapshot has changed the ortho matrix.
*/
kFlagDirtyOrtho = 0x8,
/**
* Indicates that this snapshot or an ancestor snapshot is
* an FBO layer.
*/
kFlagFboTarget = 0x10
};
/**
* Modifies the current clip with the new clip rectangle and
* the specified operation. The specified rectangle is transformed
* by this snapshot's trasnformation.
*/
bool clip(float left, float top, float right, float bottom,
SkRegion::Op op = SkRegion::kIntersect_Op) {
Rect r(left, top, right, bottom);
transform->mapRect(r);
return clipTransformed(r, op);
}
/**
* Modifies the current clip with the new clip rectangle and
* the specified operation. The specified rectangle is considered
* already transformed.
*/
bool clipTransformed(const Rect& r, SkRegion::Op op = SkRegion::kIntersect_Op) {
bool clipped = false;
// NOTE: The unimplemented operations require support for regions
// Supporting regions would require using a stencil buffer instead
// of the scissor. The stencil buffer itself is not too expensive
// (memory cost excluded) but on fillrate limited devices, managing
// the stencil might have a negative impact on the framerate.
switch (op) {
case SkRegion::kDifference_Op:
break;
case SkRegion::kIntersect_Op:
clipped = clipRect->intersect(r);
if (!clipped) {
clipRect->setEmpty();
clipped = true;
}
break;
case SkRegion::kUnion_Op:
clipped = clipRect->unionWith(r);
break;
case SkRegion::kXOR_Op:
break;
case SkRegion::kReverseDifference_Op:
break;
case SkRegion::kReplace_Op:
clipRect->set(r);
clipped = true;
break;
}
if (clipped) {
flags |= Snapshot::kFlagClipSet;
}
return clipped;
}
/**
* Sets the current clip.
*/
void setClip(float left, float top, float right, float bottom) {
clipRect->set(left, top, right, bottom);
flags |= Snapshot::kFlagClipSet;
}
const Rect& getLocalClip() {
mat4 inverse;
inverse.loadInverse(*transform);
mLocalClip.set(*clipRect);
inverse.mapRect(mLocalClip);
return mLocalClip;
}
void resetTransform(float x, float y, float z) {
transform = &mTransformRoot;
transform->loadTranslate(x, y, z);
}
void resetClip(float left, float top, float right, float bottom) {
clipRect = &mClipRectRoot;
clipRect->set(left, top, right, bottom);
flags |= Snapshot::kFlagClipSet;
}
bool isIgnored() const {
return invisible || empty;
}
/**
* Dirty flags.
*/
int flags;
/**
* Previous snapshot.
*/
sp<Snapshot> previous;
/**
* Only set when the flag kFlagIsLayer is set.
*/
Layer* layer;
/**
* Only set when the flag kFlagIsFboLayer is set.
*/
GLuint fbo;
/**
* Indicates that this snapshot is invisible and nothing should be drawn
* inside it. This flag is set only when the layer clips drawing to its
* bounds and is passed to subsequent snapshots.
*/
bool invisible;
/**
* If set to true, the layer will not be composited. This is similar to
* invisible but this flag is not passed to subsequent snapshots.
*/
bool empty;
/**
* Current viewport.
*/
Rect viewport;
/**
* Height of the framebuffer the snapshot is rendering into.
*/
int height;
/**
* Contains the previous ortho matrix.
*/
mat4 orthoMatrix;
/**
* Local transformation. Holds the current translation, scale and
* rotation values.
*/
mat4* transform;
/**
* Current clip region. The clip is stored in canvas-space coordinates,
* (screen-space coordinates in the regular case.)
*/
Rect* clipRect;
/**
* The ancestor layer's dirty region.
*/
Region* region;
private:
mat4 mTransformRoot;
Rect mClipRectRoot;
Rect mLocalClip;
}; // class Snapshot
}; // namespace uirenderer
}; // namespace android
#endif // ANDROID_HWUI_SNAPSHOT_H