paulxstretch/deps/juce/modules/juce_graphics/geometry/juce_EdgeTable.cpp

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/*
==============================================================================
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
{
JUCE_BEGIN_IGNORE_WARNINGS_MSVC (6255 6263 6386)
EdgeTable::EdgeTable (Rectangle<int> area, const Path& path, const AffineTransform& transform)
: bounds (area),
// this is a very vague heuristic to make a rough guess at a good table size
// for a given path, such that it's big enough to mostly avoid remapping, but also
// not so big that it's wasteful for simple paths.
maxEdgesPerLine (jmax (defaultEdgesPerLine / 2,
4 * (int) std::sqrt (path.data.size()))),
lineStrideElements (maxEdgesPerLine * 2 + 1)
{
allocate();
int* t = table;
for (int i = bounds.getHeight(); --i >= 0;)
{
*t = 0;
t += lineStrideElements;
}
auto leftLimit = scale * bounds.getX();
auto topLimit = scale * bounds.getY();
auto rightLimit = scale * bounds.getRight();
auto heightLimit = scale * bounds.getHeight();
PathFlatteningIterator iter (path, transform);
while (iter.next())
{
auto y1 = roundToInt (iter.y1 * 256.0f);
auto y2 = roundToInt (iter.y2 * 256.0f);
if (y1 != y2)
{
y1 -= topLimit;
y2 -= topLimit;
auto startY = y1;
int direction = -1;
if (y1 > y2)
{
std::swap (y1, y2);
direction = 1;
}
if (y1 < 0)
y1 = 0;
if (y2 > heightLimit)
y2 = heightLimit;
if (y1 < y2)
{
const double startX = 256.0f * iter.x1;
const double multiplier = (iter.x2 - iter.x1) / (iter.y2 - iter.y1);
auto stepSize = jlimit (1, 256, 256 / (1 + (int) std::abs (multiplier)));
do
{
auto step = jmin (stepSize, y2 - y1, 256 - (y1 & 255));
auto x = roundToInt (startX + multiplier * ((y1 + (step >> 1)) - startY));
if (x < leftLimit)
x = leftLimit;
else if (x >= rightLimit)
x = rightLimit - 1;
addEdgePoint (x, y1 / scale, direction * step);
y1 += step;
}
while (y1 < y2);
}
}
}
sanitiseLevels (path.isUsingNonZeroWinding());
}
EdgeTable::EdgeTable (Rectangle<int> rectangleToAdd)
: bounds (rectangleToAdd),
maxEdgesPerLine (defaultEdgesPerLine),
lineStrideElements (defaultEdgesPerLine * 2 + 1)
{
allocate();
table[0] = 0;
auto x1 = scale * rectangleToAdd.getX();
auto x2 = scale * rectangleToAdd.getRight();
int* t = table;
for (int i = rectangleToAdd.getHeight(); --i >= 0;)
{
t[0] = 2;
t[1] = x1;
t[2] = 255;
t[3] = x2;
t[4] = 0;
t += lineStrideElements;
}
}
EdgeTable::EdgeTable (const RectangleList<int>& rectanglesToAdd)
: bounds (rectanglesToAdd.getBounds()),
maxEdgesPerLine (defaultEdgesPerLine),
lineStrideElements (defaultEdgesPerLine * 2 + 1),
needToCheckEmptiness (true)
{
allocate();
clearLineSizes();
for (auto& r : rectanglesToAdd)
{
auto x1 = scale * r.getX();
auto x2 = scale * r.getRight();
auto y = r.getY() - bounds.getY();
for (int j = r.getHeight(); --j >= 0;)
addEdgePointPair (x1, x2, y++, 255);
}
sanitiseLevels (true);
}
EdgeTable::EdgeTable (const RectangleList<float>& rectanglesToAdd)
: bounds (rectanglesToAdd.getBounds().getSmallestIntegerContainer()),
maxEdgesPerLine (rectanglesToAdd.getNumRectangles() * 2),
lineStrideElements (rectanglesToAdd.getNumRectangles() * 4 + 1)
{
bounds.setHeight (bounds.getHeight() + 1);
allocate();
clearLineSizes();
for (auto& r : rectanglesToAdd)
{
auto x1 = roundToInt ((float) scale * r.getX());
auto x2 = roundToInt ((float) scale * r.getRight());
auto y1 = roundToInt ((float) scale * r.getY()) - (bounds.getY() * scale);
auto y2 = roundToInt ((float) scale * r.getBottom()) - (bounds.getY() * scale);
if (x2 <= x1 || y2 <= y1)
continue;
auto y = y1 / scale;
auto lastLine = y2 / scale;
if (y == lastLine)
{
addEdgePointPair (x1, x2, y, y2 - y1);
}
else
{
addEdgePointPair (x1, x2, y++, 255 - (y1 & 255));
while (y < lastLine)
addEdgePointPair (x1, x2, y++, 255);
jassert (y < bounds.getHeight());
addEdgePointPair (x1, x2, y, y2 & 255);
}
}
sanitiseLevels (true);
}
EdgeTable::EdgeTable (Rectangle<float> rectangleToAdd)
: bounds ((int) std::floor (rectangleToAdd.getX()),
roundToInt (rectangleToAdd.getY() * 256.0f) / scale,
2 + (int) rectangleToAdd.getWidth(),
2 + (int) rectangleToAdd.getHeight()),
maxEdgesPerLine (defaultEdgesPerLine),
lineStrideElements ((defaultEdgesPerLine * 2) + 1)
{
jassert (! rectangleToAdd.isEmpty());
allocate();
table[0] = 0;
auto x1 = roundToInt ((float) scale * rectangleToAdd.getX());
auto x2 = roundToInt ((float) scale * rectangleToAdd.getRight());
auto y1 = roundToInt ((float) scale * rectangleToAdd.getY()) - (bounds.getY() * scale);
auto y2 = roundToInt ((float) scale * rectangleToAdd.getBottom()) - (bounds.getY() * scale);
jassert (y1 < 256);
if (x2 <= x1 || y2 <= y1)
{
bounds.setHeight (0);
return;
}
int lineY = 0;
int* t = table;
if ((y1 / scale) == (y2 / scale))
{
t[0] = 2;
t[1] = x1;
t[2] = y2 - y1;
t[3] = x2;
t[4] = 0;
++lineY;
t += lineStrideElements;
}
else
{
t[0] = 2;
t[1] = x1;
t[2] = 255 - (y1 & 255);
t[3] = x2;
t[4] = 0;
++lineY;
t += lineStrideElements;
while (lineY < (y2 / scale))
{
t[0] = 2;
t[1] = x1;
t[2] = 255;
t[3] = x2;
t[4] = 0;
++lineY;
t += lineStrideElements;
}
jassert (lineY < bounds.getHeight());
t[0] = 2;
t[1] = x1;
t[2] = y2 & 255;
t[3] = x2;
t[4] = 0;
++lineY;
t += lineStrideElements;
}
while (lineY < bounds.getHeight())
{
t[0] = 0;
t += lineStrideElements;
++lineY;
}
}
EdgeTable::EdgeTable (const EdgeTable& other)
{
operator= (other);
}
EdgeTable& EdgeTable::operator= (const EdgeTable& other)
{
bounds = other.bounds;
maxEdgesPerLine = other.maxEdgesPerLine;
lineStrideElements = other.lineStrideElements;
needToCheckEmptiness = other.needToCheckEmptiness;
allocate();
copyEdgeTableData (table, lineStrideElements, other.table, lineStrideElements, bounds.getHeight());
return *this;
}
EdgeTable::~EdgeTable()
{
}
//==============================================================================
static size_t getEdgeTableAllocationSize (int lineStride, int height) noexcept
{
// (leave an extra line at the end for use as scratch space)
return (size_t) (lineStride * (2 + jmax (0, height)));
}
void EdgeTable::allocate()
{
table.malloc (getEdgeTableAllocationSize (lineStrideElements, bounds.getHeight()));
}
void EdgeTable::clearLineSizes() noexcept
{
int* t = table;
for (int i = bounds.getHeight(); --i >= 0;)
{
*t = 0;
t += lineStrideElements;
}
}
void EdgeTable::copyEdgeTableData (int* dest, int destLineStride, const int* src, int srcLineStride, int numLines) noexcept
{
while (--numLines >= 0)
{
memcpy (dest, src, (size_t) (src[0] * 2 + 1) * sizeof (int));
src += srcLineStride;
dest += destLineStride;
}
}
void EdgeTable::sanitiseLevels (const bool useNonZeroWinding) noexcept
{
// Convert the table from relative windings to absolute levels..
int* lineStart = table;
for (int y = bounds.getHeight(); --y >= 0;)
{
auto num = lineStart[0];
if (num > 0)
{
auto* items = reinterpret_cast<LineItem*> (lineStart + 1);
auto* itemsEnd = items + num;
// sort the X coords
std::sort (items, itemsEnd);
auto* src = items;
auto correctedNum = num;
int level = 0;
while (src < itemsEnd)
{
level += src->level;
auto x = src->x;
++src;
while (src < itemsEnd && src->x == x)
{
level += src->level;
++src;
--correctedNum;
}
auto corrected = std::abs (level);
if (corrected / scale)
{
if (useNonZeroWinding)
{
corrected = 255;
}
else
{
corrected &= 511;
if (corrected / scale)
corrected = 511 - corrected;
}
}
items->x = x;
items->level = corrected;
++items;
}
lineStart[0] = correctedNum;
(items - 1)->level = 0; // force the last level to 0, just in case something went wrong in creating the table
}
lineStart += lineStrideElements;
}
}
void EdgeTable::remapTableForNumEdges (const int newNumEdgesPerLine)
{
if (newNumEdgesPerLine != maxEdgesPerLine)
{
maxEdgesPerLine = newNumEdgesPerLine;
jassert (bounds.getHeight() > 0);
auto newLineStrideElements = maxEdgesPerLine * 2 + 1;
HeapBlock<int> newTable (getEdgeTableAllocationSize (newLineStrideElements, bounds.getHeight()));
copyEdgeTableData (newTable, newLineStrideElements, table, lineStrideElements, bounds.getHeight());
table.swapWith (newTable);
lineStrideElements = newLineStrideElements;
}
}
inline void EdgeTable::remapWithExtraSpace (int numPoints)
{
remapTableForNumEdges (numPoints * 2);
jassert (numPoints < maxEdgesPerLine);
}
void EdgeTable::optimiseTable()
{
int maxLineElements = 0;
for (int i = bounds.getHeight(); --i >= 0;)
maxLineElements = jmax (maxLineElements, table[i * lineStrideElements]);
remapTableForNumEdges (maxLineElements);
}
void EdgeTable::addEdgePoint (const int x, const int y, const int winding)
{
jassert (y >= 0 && y < bounds.getHeight());
auto* line = table + lineStrideElements * y;
auto numPoints = line[0];
if (numPoints >= maxEdgesPerLine)
{
remapWithExtraSpace (numPoints);
line = table + lineStrideElements * y;
}
line[0] = numPoints + 1;
line += numPoints * 2;
line[1] = x;
line[2] = winding;
}
void EdgeTable::addEdgePointPair (int x1, int x2, int y, int winding)
{
jassert (y >= 0 && y < bounds.getHeight());
auto* line = table + lineStrideElements * y;
auto numPoints = line[0];
if (numPoints + 1 >= maxEdgesPerLine)
{
remapWithExtraSpace (numPoints + 1);
line = table + lineStrideElements * y;
}
line[0] = numPoints + 2;
line += numPoints * 2;
line[1] = x1;
line[2] = winding;
line[3] = x2;
line[4] = -winding;
}
void EdgeTable::translate (float dx, int dy) noexcept
{
bounds.translate ((int) std::floor (dx), dy);
int* lineStart = table;
auto intDx = (int) (dx * 256.0f);
for (int i = bounds.getHeight(); --i >= 0;)
{
auto* line = lineStart;
lineStart += lineStrideElements;
auto num = *line++;
while (--num >= 0)
{
*line += intDx;
line += 2;
}
}
}
void EdgeTable::multiplyLevels (float amount)
{
int* lineStart = table;
auto multiplier = (int) (amount * 256.0f);
for (int y = 0; y < bounds.getHeight(); ++y)
{
auto numPoints = lineStart[0];
auto* item = reinterpret_cast<LineItem*> (lineStart + 1);
lineStart += lineStrideElements;
while (--numPoints > 0)
{
item->level = jmin (255, (item->level * multiplier) / scale);
++item;
}
}
}
void EdgeTable::intersectWithEdgeTableLine (const int y, const int* const otherLine)
{
jassert (y >= 0 && y < bounds.getHeight());
auto* srcLine = table + lineStrideElements * y;
auto srcNum1 = *srcLine;
if (srcNum1 == 0)
return;
auto srcNum2 = *otherLine;
if (srcNum2 == 0)
{
*srcLine = 0;
return;
}
auto right = bounds.getRight() * scale;
// optimise for the common case where our line lies entirely within a
// single pair of points, as happens when clipping to a simple rect.
if (srcNum2 == 2 && otherLine[2] >= 255)
{
clipEdgeTableLineToRange (srcLine, otherLine[1], jmin (right, otherLine[3]));
return;
}
bool isUsingTempSpace = false;
const int* src1 = srcLine + 1;
auto x1 = *src1++;
const int* src2 = otherLine + 1;
auto x2 = *src2++;
int destIndex = 0, destTotal = 0;
int level1 = 0, level2 = 0;
int lastX = std::numeric_limits<int>::min(), lastLevel = 0;
while (srcNum1 > 0 && srcNum2 > 0)
{
int nextX;
if (x1 <= x2)
{
if (x1 == x2)
{
level2 = *src2++;
x2 = *src2++;
--srcNum2;
}
nextX = x1;
level1 = *src1++;
x1 = *src1++;
--srcNum1;
}
else
{
nextX = x2;
level2 = *src2++;
x2 = *src2++;
--srcNum2;
}
if (nextX > lastX)
{
if (nextX >= right)
break;
lastX = nextX;
auto nextLevel = (level1 * (level2 + 1)) / scale;
jassert (isPositiveAndBelow (nextLevel, 256));
if (nextLevel != lastLevel)
{
if (destTotal >= maxEdgesPerLine)
{
srcLine[0] = destTotal;
if (isUsingTempSpace)
{
auto tempSize = (size_t) srcNum1 * 2 * sizeof (int);
auto oldTemp = static_cast<int*> (alloca (tempSize));
memcpy (oldTemp, src1, tempSize);
remapTableForNumEdges (jmax (256, destTotal * 2));
srcLine = table + lineStrideElements * y;
auto* newTemp = table + lineStrideElements * bounds.getHeight();
memcpy (newTemp, oldTemp, tempSize);
src1 = newTemp;
}
else
{
remapTableForNumEdges (jmax (256, destTotal * 2));
srcLine = table + lineStrideElements * y;
}
}
++destTotal;
lastLevel = nextLevel;
if (! isUsingTempSpace)
{
isUsingTempSpace = true;
auto* temp = table + lineStrideElements * bounds.getHeight();
memcpy (temp, src1, (size_t) srcNum1 * 2 * sizeof (int));
src1 = temp;
}
srcLine[++destIndex] = nextX;
srcLine[++destIndex] = nextLevel;
}
}
}
if (lastLevel > 0)
{
if (destTotal >= maxEdgesPerLine)
{
srcLine[0] = destTotal;
remapTableForNumEdges (jmax (256, destTotal * 2));
srcLine = table + lineStrideElements * y;
}
++destTotal;
srcLine[++destIndex] = right;
srcLine[++destIndex] = 0;
}
srcLine[0] = destTotal;
}
void EdgeTable::clipEdgeTableLineToRange (int* dest, const int x1, const int x2) noexcept
{
int* lastItem = dest + (dest[0] * 2 - 1);
if (x2 < lastItem[0])
{
if (x2 <= dest[1])
{
dest[0] = 0;
return;
}
while (x2 < lastItem[-2])
{
--(dest[0]);
lastItem -= 2;
}
lastItem[0] = x2;
lastItem[1] = 0;
}
if (x1 > dest[1])
{
while (lastItem[0] > x1)
lastItem -= 2;
auto itemsRemoved = (int) (lastItem - (dest + 1)) / 2;
if (itemsRemoved > 0)
{
dest[0] -= itemsRemoved;
memmove (dest + 1, lastItem, (size_t) dest[0] * (sizeof (int) * 2));
}
dest[1] = x1;
}
}
//==============================================================================
void EdgeTable::clipToRectangle (Rectangle<int> r)
{
auto clipped = r.getIntersection (bounds);
if (clipped.isEmpty())
{
needToCheckEmptiness = false;
bounds.setHeight (0);
}
else
{
auto top = clipped.getY() - bounds.getY();
auto bottom = clipped.getBottom() - bounds.getY();
if (bottom < bounds.getHeight())
bounds.setHeight (bottom);
for (int i = 0; i < top; ++i)
table[lineStrideElements * i] = 0;
if (clipped.getX() > bounds.getX() || clipped.getRight() < bounds.getRight())
{
auto x1 = scale * clipped.getX();
auto x2 = scale * jmin (bounds.getRight(), clipped.getRight());
int* line = table + lineStrideElements * top;
for (int i = bottom - top; --i >= 0;)
{
if (line[0] != 0)
clipEdgeTableLineToRange (line, x1, x2);
line += lineStrideElements;
}
}
needToCheckEmptiness = true;
}
}
void EdgeTable::excludeRectangle (Rectangle<int> r)
{
auto clipped = r.getIntersection (bounds);
if (! clipped.isEmpty())
{
auto top = clipped.getY() - bounds.getY();
auto bottom = clipped.getBottom() - bounds.getY();
const int rectLine[] = { 4, std::numeric_limits<int>::min(), 255,
scale * clipped.getX(), 0,
scale * clipped.getRight(), 255,
std::numeric_limits<int>::max(), 0 };
for (int i = top; i < bottom; ++i)
intersectWithEdgeTableLine (i, rectLine);
needToCheckEmptiness = true;
}
}
void EdgeTable::clipToEdgeTable (const EdgeTable& other)
{
auto clipped = other.bounds.getIntersection (bounds);
if (clipped.isEmpty())
{
needToCheckEmptiness = false;
bounds.setHeight (0);
}
else
{
auto top = clipped.getY() - bounds.getY();
auto bottom = clipped.getBottom() - bounds.getY();
if (bottom < bounds.getHeight())
bounds.setHeight (bottom);
if (clipped.getRight() < bounds.getRight())
bounds.setRight (clipped.getRight());
for (int i = 0; i < top; ++i)
table[lineStrideElements * i] = 0;
auto* otherLine = other.table + other.lineStrideElements * (clipped.getY() - other.bounds.getY());
for (int i = top; i < bottom; ++i)
{
intersectWithEdgeTableLine (i, otherLine);
otherLine += other.lineStrideElements;
}
needToCheckEmptiness = true;
}
}
void EdgeTable::clipLineToMask (int x, int y, const uint8* mask, int maskStride, int numPixels)
{
y -= bounds.getY();
if (y < 0 || y >= bounds.getHeight())
return;
needToCheckEmptiness = true;
if (numPixels <= 0)
{
table[lineStrideElements * y] = 0;
return;
}
auto* tempLine = static_cast<int*> (alloca ((size_t) (numPixels * 2 + 4) * sizeof (int)));
int destIndex = 0, lastLevel = 0;
while (--numPixels >= 0)
{
auto alpha = *mask;
mask += maskStride;
if (alpha != lastLevel)
{
tempLine[++destIndex] = (x * scale);
tempLine[++destIndex] = alpha;
lastLevel = alpha;
}
++x;
}
if (lastLevel > 0)
{
tempLine[++destIndex] = (x * scale);
tempLine[++destIndex] = 0;
}
tempLine[0] = destIndex >> 1;
intersectWithEdgeTableLine (y, tempLine);
}
bool EdgeTable::isEmpty() noexcept
{
if (needToCheckEmptiness)
{
needToCheckEmptiness = false;
int* t = table;
for (int i = bounds.getHeight(); --i >= 0;)
{
if (t[0] > 1)
return false;
t += lineStrideElements;
}
bounds.setHeight (0);
}
return bounds.getHeight() == 0;
}
JUCE_END_IGNORE_WARNINGS_MSVC
} // namespace juce