haiku/headers/private/interface/ShapePrivate.h
Julian Harnath b54b3ae511 app_server: add a cache for AlphaMasks
* If the same shape alpha mask is set again and again, we now keep
  the rendered masks in a cache. On certain websites, WebKit sets
  the same shape for clipping hundreds of times, which uses a lot
  of time to render the masks.

* When a shape mask was generated, we put it into AlphaMaskCache.
  The constructor for ShapeAlphaMask is made private and a factory
  method is used for instantiation instead, which transparently
  looks up in the cache whether a suitable mask was already generated
  before (so the entire caching is encapsulated inside the AlphaMask
  class).

* When taking a mask out of the cache, we still create a new
  AlphaMask instance. However, the new instance will share the
  mask bitmap with the previously generated instance (aside from
  the rendering of their bitmap, AlphaMask instances are pretty
  lightweight). Shape masks are only seen as identical when
  their shape is the same, the inverse flag, and they have the
  same parent mask.

* Cache is limited to a fixed size of currently 8 MiB, using a
  simple random replacement scheme. An LRU scheme can be added in
  the future if necessary. Counting of bytes for the cache size
  includes parent masks of masks in the cache, even if the parent
  itself is not cached. A reference counter for "indirect" cache
  references keeps track of which masks are not part of the cache,
  but still need to be added to the cache byte size.

* For now, only for ShapeAlphaMasks, other mask types can be added
  as necessary.
2015-11-14 16:09:52 +01:00

100 lines
1.9 KiB
C++

/*
* Copyright 2003-2010 Haiku, Inc. All rights reserved.
* Distributed under the terms of the MIT License.
*
* Authors:
* Axel Dörfler, axeld@pinc-software.de
* Adrian Oanca, adioanca@cotty.iren.ro
*/
#ifndef SHAPE_PRIVATE_H
#define SHAPE_PRIVATE_H
#include <Point.h>
#include <Rect.h>
#include <Referenceable.h>
#include <string.h>
#include <stdio.h>
#define OP_LINETO 0x10000000
#define OP_BEZIERTO 0x20000000
#define OP_CLOSE 0x40000000
#define OP_MOVETO 0x80000000
#define OP_LARGE_ARC_TO_CW 0x01000000
#define OP_LARGE_ARC_TO_CCW 0x02000000
#define OP_SMALL_ARC_TO_CW 0x04000000
#define OP_SMALL_ARC_TO_CCW 0x08000000
struct shape_data : public BReferenceable {
uint32* opList;
BPoint* ptList;
int32 opCount;
int32 opSize;
int32 ptCount;
int32 ptSize;
bool fOwnsMemory;
shape_data()
:
fOwnsMemory(false)
{
}
~shape_data()
{
if (fOwnsMemory) {
delete[] opList;
delete[] ptList;
}
}
shape_data(const shape_data& other)
{
opList = new(std::nothrow) uint32[other.opCount];
ptList = new(std::nothrow) BPoint[other.ptCount];
fOwnsMemory = true;
opCount = other.opCount;
opSize = other.opSize;
ptCount = other.ptCount;
ptSize = other.ptSize;
memcpy(opList, other.opList, opSize);
memcpy(ptList, other.ptList, ptSize);
}
BRect DetermineBoundingBox() const
{
BRect bounds;
if (ptCount == 0)
return bounds;
// TODO: This implementation doesn't take into account curves at all.
bounds.left = ptList[0].x;
bounds.top = ptList[0].y;
bounds.right = ptList[0].x;
bounds.bottom = ptList[0].y;
for (int32 i = 1; i < ptCount; i++) {
if (bounds.left > ptList[i].x)
bounds.left = ptList[i].x;
if (bounds.top > ptList[i].y)
bounds.top = ptList[i].y;
if (bounds.right < ptList[i].x)
bounds.right = ptList[i].x;
if (bounds.bottom < ptList[i].y)
bounds.bottom = ptList[i].y;
}
return bounds;
}
};
#endif // SHAPE_PRIVATE_H