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      1 /*
      2  * Copyright (C) 2010 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 #ifndef ANDROID_HWUI_SNAPSHOT_H
     18 #define ANDROID_HWUI_SNAPSHOT_H
     19 
     20 #include <GLES2/gl2.h>
     21 #include <GLES2/gl2ext.h>
     22 
     23 #include <utils/LinearAllocator.h>
     24 #include <utils/RefBase.h>
     25 #include <ui/Region.h>
     26 
     27 #include <SkRegion.h>
     28 
     29 #include "ClipArea.h"
     30 #include "Layer.h"
     31 #include "Matrix.h"
     32 #include "Outline.h"
     33 #include "Rect.h"
     34 #include "utils/Macros.h"
     35 
     36 namespace android {
     37 namespace uirenderer {
     38 
     39 /**
     40  * Temporary structure holding information for a single outline clip.
     41  *
     42  * These structures are treated as immutable once created, and only exist for a single frame, which
     43  * is why they may only be allocated with a LinearAllocator.
     44  */
     45 class RoundRectClipState {
     46 public:
     47     /** static void* operator new(size_t size); PURPOSELY OMITTED, allocator only **/
     48     static void* operator new(size_t size, LinearAllocator& allocator) {
     49         return allocator.alloc(size);
     50     }
     51 
     52     bool areaRequiresRoundRectClip(const Rect& rect) const {
     53         return rect.intersects(dangerRects[0])
     54                 || rect.intersects(dangerRects[1])
     55                 || rect.intersects(dangerRects[2])
     56                 || rect.intersects(dangerRects[3]);
     57     }
     58 
     59     bool highPriority;
     60     Matrix4 matrix;
     61     Rect dangerRects[4];
     62     Rect innerRect;
     63     float radius;
     64 };
     65 
     66 class ProjectionPathMask {
     67 public:
     68     /** static void* operator new(size_t size); PURPOSELY OMITTED, allocator only **/
     69     static void* operator new(size_t size, LinearAllocator& allocator) {
     70         return allocator.alloc(size);
     71     }
     72 
     73     const SkPath* projectionMask;
     74     Matrix4 projectionMaskTransform;
     75 };
     76 
     77 /**
     78  * A snapshot holds information about the current state of the rendering
     79  * surface. A snapshot is usually created whenever the user calls save()
     80  * and discarded when the user calls restore(). Once a snapshot is created,
     81  * it can hold information for deferred rendering.
     82  *
     83  * Each snapshot has a link to a previous snapshot, indicating the previous
     84  * state of the renderer.
     85  */
     86 class Snapshot: public LightRefBase<Snapshot> {
     87 public:
     88 
     89     Snapshot();
     90     Snapshot(const sp<Snapshot>& s, int saveFlags);
     91 
     92     /**
     93      * Various flags set on ::flags.
     94      */
     95     enum Flags {
     96         /**
     97          * Indicates that the clip region was modified. When this
     98          * snapshot is restored so must the clip.
     99          */
    100         kFlagClipSet = 0x1,
    101         /**
    102          * Indicates that this snapshot was created when saving
    103          * a new layer.
    104          */
    105         kFlagIsLayer = 0x2,
    106         /**
    107          * Indicates that this snapshot is a special type of layer
    108          * backed by an FBO. This flag only makes sense when the
    109          * flag kFlagIsLayer is also set.
    110          *
    111          * Viewport has been modified to fit the new Fbo, and must be
    112          * restored when this snapshot is restored.
    113          */
    114         kFlagIsFboLayer = 0x4,
    115         /**
    116          * Indicates that this snapshot or an ancestor snapshot is
    117          * an FBO layer.
    118          */
    119         kFlagFboTarget = 0x8,
    120     };
    121 
    122     /**
    123      * Modifies the current clip with the new clip rectangle and
    124      * the specified operation. The specified rectangle is transformed
    125      * by this snapshot's trasnformation.
    126      */
    127     bool clip(float left, float top, float right, float bottom,
    128             SkRegion::Op op = SkRegion::kIntersect_Op);
    129 
    130     /**
    131      * Modifies the current clip with the new clip rectangle and
    132      * the specified operation. The specified rectangle is considered
    133      * already transformed.
    134      */
    135     bool clipTransformed(const Rect& r, SkRegion::Op op = SkRegion::kIntersect_Op);
    136 
    137     /**
    138      * Modifies the current clip with the specified region and operation.
    139      * The specified region is considered already transformed.
    140      */
    141     bool clipRegionTransformed(const SkRegion& region, SkRegion::Op op);
    142 
    143     /**
    144      * Modifies the current clip with the specified path and operation.
    145      */
    146     bool clipPath(const SkPath& path, SkRegion::Op op);
    147 
    148     /**
    149      * Sets the current clip.
    150      */
    151     void setClip(float left, float top, float right, float bottom);
    152 
    153     /**
    154      * Returns the current clip in local coordinates. The clip rect is
    155      * transformed by the inverse transform matrix.
    156      */
    157     ANDROID_API const Rect& getLocalClip();
    158 
    159     /**
    160      * Returns the current clip in render target coordinates.
    161      */
    162     const Rect& getRenderTargetClip() { return mClipArea->getClipRect(); }
    163 
    164     /*
    165      * Accessor functions so that the clip area can stay private
    166      */
    167     bool clipIsEmpty() const { return mClipArea->isEmpty(); }
    168     const Rect& getClipRect() const { return mClipArea->getClipRect(); }
    169     const SkRegion& getClipRegion() const { return mClipArea->getClipRegion(); }
    170     bool clipIsSimple() const { return mClipArea->isSimple(); }
    171     const ClipArea& getClipArea() const { return *mClipArea; }
    172 
    173     /**
    174      * Resets the clip to the specified rect.
    175      */
    176     void resetClip(float left, float top, float right, float bottom);
    177 
    178     /**
    179      * Resets the current transform to a pure 3D translation.
    180      */
    181     void resetTransform(float x, float y, float z);
    182 
    183     void initializeViewport(int width, int height) {
    184         mViewportData.initialize(width, height);
    185         mClipAreaRoot.setViewportDimensions(width, height);
    186     }
    187 
    188     int getViewportWidth() const { return mViewportData.mWidth; }
    189     int getViewportHeight() const { return mViewportData.mHeight; }
    190     const Matrix4& getOrthoMatrix() const { return mViewportData.mOrthoMatrix; }
    191 
    192     const Vector3& getRelativeLightCenter() const { return mRelativeLightCenter; }
    193     void setRelativeLightCenter(const Vector3& lightCenter) { mRelativeLightCenter = lightCenter; }
    194 
    195     /**
    196      * Sets (and replaces) the current clipping outline
    197      *
    198      * If the current round rect clip is high priority, the incoming clip is ignored.
    199      */
    200     void setClippingRoundRect(LinearAllocator& allocator, const Rect& bounds,
    201             float radius, bool highPriority);
    202 
    203     /**
    204      * Sets (and replaces) the current projection mask
    205      */
    206     void setProjectionPathMask(LinearAllocator& allocator, const SkPath* path);
    207 
    208     /**
    209      * Indicates whether this snapshot should be ignored. A snapshot
    210      * is typically ignored if its layer is invisible or empty.
    211      */
    212     bool isIgnored() const;
    213 
    214     /**
    215      * Indicates whether the current transform has perspective components.
    216      */
    217     bool hasPerspectiveTransform() const;
    218 
    219     /**
    220      * Fills outTransform with the current, total transform to screen space,
    221      * across layer boundaries.
    222      */
    223     void buildScreenSpaceTransform(Matrix4* outTransform) const;
    224 
    225     /**
    226      * Dirty flags.
    227      */
    228     int flags;
    229 
    230     /**
    231      * Previous snapshot.
    232      */
    233     sp<Snapshot> previous;
    234 
    235     /**
    236      * A pointer to the currently active layer.
    237      *
    238      * This snapshot does not own the layer, this pointer must not be freed.
    239      */
    240     Layer* layer;
    241 
    242     /**
    243      * Target FBO used for rendering. Set to 0 when rendering directly
    244      * into the framebuffer.
    245      */
    246     GLuint fbo;
    247 
    248     /**
    249      * Indicates that this snapshot is invisible and nothing should be drawn
    250      * inside it. This flag is set only when the layer clips drawing to its
    251      * bounds and is passed to subsequent snapshots.
    252      */
    253     bool invisible;
    254 
    255     /**
    256      * If set to true, the layer will not be composited. This is similar to
    257      * invisible but this flag is not passed to subsequent snapshots.
    258      */
    259     bool empty;
    260 
    261     /**
    262      * Local transformation. Holds the current translation, scale and
    263      * rotation values.
    264      *
    265      * This is a reference to a matrix owned by this snapshot or another
    266      *  snapshot. This pointer must not be freed. See ::mTransformRoot.
    267      */
    268     mat4* transform;
    269 
    270     /**
    271      * The ancestor layer's dirty region.
    272      *
    273      * This is a reference to a region owned by a layer. This pointer must
    274      * not be freed.
    275      */
    276     Region* region;
    277 
    278     /**
    279      * Current alpha value. This value is 1 by default, but may be set by a DisplayList which
    280      * has translucent rendering in a non-overlapping View. This value will be used by
    281      * the renderer to set the alpha in the current color being used for ensuing drawing
    282      * operations. The value is inherited by child snapshots because the same value should
    283      * be applied to descendants of the current DisplayList (for example, a TextView contains
    284      * the base alpha value which should be applied to the child DisplayLists used for drawing
    285      * the actual text).
    286      */
    287     float alpha;
    288 
    289     /**
    290      * Current clipping round rect.
    291      *
    292      * Points to data not owned by the snapshot, and may only be replaced by subsequent RR clips,
    293      * never modified.
    294      */
    295     const RoundRectClipState* roundRectClipState;
    296 
    297     /**
    298      * Current projection masking path - used exclusively to mask tessellated circles.
    299      */
    300     const ProjectionPathMask* projectionPathMask;
    301 
    302     void dump() const;
    303 
    304 private:
    305     struct ViewportData {
    306         ViewportData() : mWidth(0), mHeight(0) {}
    307         void initialize(int width, int height) {
    308             mWidth = width;
    309             mHeight = height;
    310             mOrthoMatrix.loadOrtho(0, width, height, 0, -1, 1);
    311         }
    312 
    313         /*
    314          * Width and height of current viewport.
    315          *
    316          * The viewport is always defined to be (0, 0, width, height).
    317          */
    318         int mWidth;
    319         int mHeight;
    320         /**
    321          * Contains the current orthographic, projection matrix.
    322          */
    323         mat4 mOrthoMatrix;
    324     };
    325 
    326     mat4 mTransformRoot;
    327 
    328     ClipArea mClipAreaRoot;
    329     ClipArea* mClipArea;
    330     Rect mLocalClip;
    331 
    332     ViewportData mViewportData;
    333     Vector3 mRelativeLightCenter;
    334 
    335 }; // class Snapshot
    336 
    337 }; // namespace uirenderer
    338 }; // namespace android
    339 
    340 #endif // ANDROID_HWUI_SNAPSHOT_H
    341