paulxstretch/deps/juce/modules/juce_graphics/geometry/juce_EdgeTable.h
essej 25bd5d8adb git subrepo clone --branch=sono6good https://github.com/essej/JUCE.git deps/juce
subrepo:
  subdir:   "deps/juce"
  merged:   "b13f9084e"
upstream:
  origin:   "https://github.com/essej/JUCE.git"
  branch:   "sono6good"
  commit:   "b13f9084e"
git-subrepo:
  version:  "0.4.3"
  origin:   "https://github.com/ingydotnet/git-subrepo.git"
  commit:   "2f68596"
2022-04-18 17:51:22 -04:00

227 lines
9.0 KiB
C++

/*
==============================================================================
This file is part of the JUCE library.
Copyright (c) 2020 - Raw Material Software Limited
JUCE is an open source library subject to commercial or open-source
licensing.
By using JUCE, you agree to the terms of both the JUCE 6 End-User License
Agreement and JUCE Privacy Policy (both effective as of the 16th June 2020).
End User License Agreement: www.juce.com/juce-6-licence
Privacy Policy: www.juce.com/juce-privacy-policy
Or: You may also use this code under the terms of the GPL v3 (see
www.gnu.org/licenses).
JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
DISCLAIMED.
==============================================================================
*/
namespace juce
{
//==============================================================================
/**
A table of horizontal scan-line segments - used for rasterising Paths.
@see Path, Graphics
@tags{Graphics}
*/
class JUCE_API EdgeTable
{
public:
//==============================================================================
/** Creates an edge table containing a path.
A table is created with a fixed vertical range, and only sections of the path
which lie within this range will be added to the table.
@param clipLimits only the region of the path that lies within this area will be added
@param pathToAdd the path to add to the table
@param transform a transform to apply to the path being added
*/
EdgeTable (Rectangle<int> clipLimits,
const Path& pathToAdd,
const AffineTransform& transform);
/** Creates an edge table containing a rectangle. */
explicit EdgeTable (Rectangle<int> rectangleToAdd);
/** Creates an edge table containing a rectangle. */
explicit EdgeTable (Rectangle<float> rectangleToAdd);
/** Creates an edge table containing a rectangle list. */
explicit EdgeTable (const RectangleList<int>& rectanglesToAdd);
/** Creates an edge table containing a rectangle list. */
explicit EdgeTable (const RectangleList<float>& rectanglesToAdd);
/** Creates a copy of another edge table. */
EdgeTable (const EdgeTable&);
/** Copies from another edge table. */
EdgeTable& operator= (const EdgeTable&);
/** Destructor. */
~EdgeTable();
//==============================================================================
void clipToRectangle (Rectangle<int> r);
void excludeRectangle (Rectangle<int> r);
void clipToEdgeTable (const EdgeTable&);
void clipLineToMask (int x, int y, const uint8* mask, int maskStride, int numPixels);
bool isEmpty() noexcept;
const Rectangle<int>& getMaximumBounds() const noexcept { return bounds; }
void translate (float dx, int dy) noexcept;
/** Scales all the alpha-levels in the table by the given multiplier. */
void multiplyLevels (float factor);
/** Reduces the amount of space the table has allocated.
This will shrink the table down to use as little memory as possible - useful for
read-only tables that get stored and re-used for rendering.
*/
void optimiseTable();
//==============================================================================
/** Iterates the lines in the table, for rendering.
This function will iterate each line in the table, and call a user-defined class
to render each pixel or continuous line of pixels that the table contains.
@param iterationCallback this templated class must contain the following methods:
@code
inline void setEdgeTableYPos (int y);
inline void handleEdgeTablePixel (int x, int alphaLevel) const;
inline void handleEdgeTablePixelFull (int x) const;
inline void handleEdgeTableLine (int x, int width, int alphaLevel) const;
inline void handleEdgeTableLineFull (int x, int width) const;
@endcode
(these don't necessarily have to be 'const', but it might help it go faster)
*/
template <class EdgeTableIterationCallback>
void iterate (EdgeTableIterationCallback& iterationCallback) const noexcept
{
const int* lineStart = table;
for (int y = 0; y < bounds.getHeight(); ++y)
{
const int* line = lineStart;
lineStart += lineStrideElements;
int numPoints = line[0];
if (--numPoints > 0)
{
int x = *++line;
jassert ((x / scale) >= bounds.getX() && (x / scale) < bounds.getRight());
int levelAccumulator = 0;
iterationCallback.setEdgeTableYPos (bounds.getY() + y);
while (--numPoints >= 0)
{
const int level = *++line;
jassert (isPositiveAndBelow (level, scale));
const int endX = *++line;
jassert (endX >= x);
const int endOfRun = (endX / scale);
if (endOfRun == (x / scale))
{
// small segment within the same pixel, so just save it for the next
// time round..
levelAccumulator += (endX - x) * level;
}
else
{
// plot the fist pixel of this segment, including any accumulated
// levels from smaller segments that haven't been drawn yet
levelAccumulator += (0x100 - (x & 0xff)) * level;
levelAccumulator /= scale;
x /= scale;
if (levelAccumulator > 0)
{
if (levelAccumulator >= 255)
iterationCallback.handleEdgeTablePixelFull (x);
else
iterationCallback.handleEdgeTablePixel (x, levelAccumulator);
}
// if there's a run of similar pixels, do it all in one go..
if (level > 0)
{
jassert (endOfRun <= bounds.getRight());
const int numPix = endOfRun - ++x;
if (numPix > 0)
iterationCallback.handleEdgeTableLine (x, numPix, level);
}
// save the bit at the end to be drawn next time round the loop.
levelAccumulator = (endX & 0xff) * level;
}
x = endX;
}
levelAccumulator /= scale;
if (levelAccumulator > 0)
{
x /= scale;
jassert (x >= bounds.getX() && x < bounds.getRight());
if (levelAccumulator >= 255)
iterationCallback.handleEdgeTablePixelFull (x);
else
iterationCallback.handleEdgeTablePixel (x, levelAccumulator);
}
}
}
}
private:
//==============================================================================
static constexpr auto defaultEdgesPerLine = 32;
static constexpr auto scale = 256;
//==============================================================================
// table line format: number of points; point0 x, point0 levelDelta, point1 x, point1 levelDelta, etc
struct LineItem
{
int x, level;
bool operator< (const LineItem& other) const noexcept { return x < other.x; }
};
HeapBlock<int> table;
Rectangle<int> bounds;
int maxEdgesPerLine, lineStrideElements;
bool needToCheckEmptiness = true;
void allocate();
void clearLineSizes() noexcept;
void addEdgePoint (int x, int y, int winding);
void addEdgePointPair (int x1, int x2, int y, int winding);
void remapTableForNumEdges (int newNumEdgesPerLine);
void remapWithExtraSpace (int numPointsNeeded);
void intersectWithEdgeTableLine (int y, const int* otherLine);
void clipEdgeTableLineToRange (int* line, int x1, int x2) noexcept;
void sanitiseLevels (bool useNonZeroWinding) noexcept;
static void copyEdgeTableData (int* dest, int destLineStride, const int* src, int srcLineStride, int numLines) noexcept;
JUCE_LEAK_DETECTOR (EdgeTable)
};
} // namespace juce