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Performance optimalization of patch meshes

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Jakub Melka
2021-03-20 18:04:58 +01:00
parent e9bff58c06
commit 67872a532f
4 changed files with 63 additions and 20 deletions
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69
Pdf4QtLib/sources/pdfpattern.cpp
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@ -2604,6 +2604,13 @@ QPointF PDFTensorPatch::getValue(PDFReal u, PDFReal v, int derivativeOrderU, int
bool PDFTensorPatch::getUV(PDFReal& u, PDFReal& v, PDFReal x, PDFReal y, PDFReal epsilon, int maximalNumberOfSteps) const
{
// First we will text, if point (x, y) is in bounding rectangle of the patch.
// If it isn't, then return false immediately, because point is not in tensor patch.
if (!m_boundingBox.contains(x, y))
{
return false;
}
int i = 0;
// Jakub Melka: We are finding root of function F(u, v) defined as:
@ -2816,6 +2823,27 @@ constexpr PDFReal PDFTensorPatch::B3(PDFReal t, int derivative)
return std::numeric_limits<PDFReal>::signaling_NaN();
}
void PDFTensorPatch::computeBoundingRectangle()
{
PDFReal xMin = std::numeric_limits<PDFReal>::infinity();
PDFReal xMax = -xMin;
PDFReal yMin = xMin;
PDFReal yMax = xMax;
for (const auto& row : m_P)
{
for (const auto& point : row)
{
xMin = qMin(xMin, point.x());
xMax = qMax(xMax, point.x());
yMin = qMin(yMin, point.y());
yMax = qMax(yMax, point.y());
}
}
m_boundingBox = QRectF(xMin, yMin, xMax - xMin, yMax - yMin);
}
ShadingType PDFTensorProductPatchShading::getShadingType() const
{
return ShadingType::TensorProductPatchMesh;
@ -3198,7 +3226,8 @@ void PDFTensorProductPatchShadingBase::fillMesh(PDFMesh& mesh,
const PDFTensorPatch& patch,
const PDFCMS* cms,
RenderingIntent intent,
PDFRenderErrorReporter* reporter) const
PDFRenderErrorReporter* reporter,
bool fastAlgorithm) const
{
// We implement algorithm similar to Ruppert's algorithm (see https://en.wikipedia.org/wiki/Ruppert%27s_algorithm), but
// we do not need a mesh for FEM calculation, so we do not care about quality of the triangles (we can have triangles with
@ -3216,24 +3245,31 @@ void PDFTensorProductPatchShadingBase::fillMesh(PDFMesh& mesh,
std::atomic<PDFReal> maximalCurvature(0.0);
Q_ASSERT(settings.patchTestPoints > 2);
const PDFReal testPointScale = 1.0 / (settings.patchTestPoints - 1.0);
PDFIntegerRange<PDFInteger> range(0, settings.patchTestPoints * settings.patchTestPoints);
auto updateCurvature = [&](PDFInteger i)
if (!fastAlgorithm)
{
PDFInteger row = i / settings.patchTestPoints;
PDFInteger column = i % settings.patchTestPoints;
Q_ASSERT(settings.patchTestPoints > 2);
const PDFReal testPointScale = 1.0 / (settings.patchTestPoints - 1.0);
PDFIntegerRange<PDFInteger> range(0, settings.patchTestPoints * settings.patchTestPoints);
auto updateCurvature = [&](PDFInteger i)
{
PDFInteger row = i / settings.patchTestPoints;
PDFInteger column = i % settings.patchTestPoints;
const PDFReal u = column * testPointScale;
const PDFReal v = row * testPointScale;
const PDFReal u = column * testPointScale;
const PDFReal v = row * testPointScale;
const PDFReal curvature = patch.getCurvature_u(u, v) + patch.getCurvature_v(u, v);
const PDFReal curvature = patch.getCurvature_u(u, v) + patch.getCurvature_v(u, v);
// Atomically update the maximum curvature
PDFReal previousCurvature = maximalCurvature;
while (previousCurvature < curvature && !maximalCurvature.compare_exchange_weak(previousCurvature, curvature)) { }
};
PDFExecutionPolicy::execute(PDFExecutionPolicy::Scope::Content, range.begin(), range.end(), updateCurvature);
// Atomically update the maximum curvature
PDFReal previousCurvature = maximalCurvature;
while (previousCurvature < curvature && !maximalCurvature.compare_exchange_weak(previousCurvature, curvature)) { }
};
std::for_each(range.begin(), range.end(), updateCurvature);
}
else
{
maximalCurvature = std::numeric_limits<PDFReal>::infinity();
}
auto getColorForUV = [&](PDFReal u, PDFReal v)
{
@ -3382,9 +3418,10 @@ void PDFTensorProductPatchShadingBase::fillMesh(PDFMesh& mesh,
RenderingIntent intent,
PDFRenderErrorReporter* reporter) const
{
const bool fastAlgorithm = patches.size() > 16;
for (const auto& patch : patches)
{
fillMesh(mesh, settings, patch, cms, intent, reporter);
fillMesh(mesh, settings, patch, cms, intent, reporter, fastAlgorithm);
}
// Create bounding path