impeller::Tessellator::ArcVertexGenerator Class Reference

The |VertexGenerator| implementation common to all shapes that are based on a polygonal representation of an ellipse. More...

#include <tessellator.h>

Inheritance diagram for impeller::Tessellator::ArcVertexGenerator:

Public Member Functions
PrimitiveType	GetTriangleType () const override
	|VertexGenerator| More...
size_t	GetVertexCount () const override
	|VertexGenerator| More...
void	GenerateVertices (const TessellatedVertexProc &proc) const override
	|VertexGenerator| More...

Friends
class	Tessellator

Detailed Description

The |VertexGenerator| implementation common to all shapes that are based on a polygonal representation of an ellipse.

Definition at line 191 of file tessellator.h.

Member Function Documentation

GenerateVertices()

void impeller::ArcVertexGenerator::GenerateVertices ( const TessellatedVertexProc &  proc ) const

overridevirtual

|VertexGenerator|

Implements impeller::Tessellator::VertexGenerator.

Definition at line 541 of file tessellator.cc.

                                             {
  if (half_width_ > 0) {
    FML_DCHECK(!use_center_);
    Tessellator::GenerateStrokedArc(trigs_, iteration_, oval_bounds_,
                                    half_width_, cap_, proc);
  } else if (supports_triangle_fans_) {
    Tessellator::GenerateFilledArcFan(trigs_, iteration_, oval_bounds_,
                                      use_center_, proc);
  } else {
    Tessellator::GenerateFilledArcStrip(trigs_, iteration_, oval_bounds_,
                                        use_center_, proc);
  }
}

GetTriangleType()

PrimitiveType impeller::ArcVertexGenerator::GetTriangleType ( ) const

overridevirtual

|VertexGenerator|

Implements impeller::Tessellator::VertexGenerator.

Definition at line 515 of file tessellator.cc.

                                                        {
  return (half_width_ < 0 && supports_triangle_fans_)
             ? PrimitiveType::kTriangleFan
             : PrimitiveType::kTriangleStrip;
}

References impeller::kTriangleFan, and impeller::kTriangleStrip.

GetVertexCount()

size_t impeller::ArcVertexGenerator::GetVertexCount ( ) const

overridevirtual

|VertexGenerator|

Implements impeller::Tessellator::VertexGenerator.

Definition at line 521 of file tessellator.cc.

                                                {
  size_t count = iteration_.GetPointCount();
  if (half_width_ > 0) {
    FML_DCHECK(!use_center_);
    FML_DCHECK(cap_ != Cap::kRound);
    count *= 2;
    if (cap_ == Cap::kSquare) {
      count += 4;
    }
  } else if (supports_triangle_fans_) {
    if (use_center_) {
      count++;
    }
  } else {
    // corrugated triangle fan
    count += (count + 1) / 2;
  }
  return count;
}

References impeller::Arc::Iteration::GetPointCount(), impeller::kRound, and impeller::kSquare.

Friends And Related Function Documentation

Tessellator

friend class Tessellator

friend

Definition at line 203 of file tessellator.h.

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The documentation for this class was generated from the following files:

• impeller/tessellator/tessellator.h
• impeller/tessellator/tessellator.cc