flutter::DlVertexPainter Class Reference

Provides canvas-like painting methods that actually build vertices. More...

#include <stopwatch_dl.h>

Public Member Functions
	DlVertexPainter (std::vector< DlPoint > &vertices_storage, std::vector< DlColor > &color_storage)
void	DrawRect (const DlRect &rect, const DlColor &color)
	Draws a rectangle with the given color to a buffer.
std::shared_ptr< DlVertices >	IntoVertices (const DlRect &bounds_rect)

Detailed Description

Provides canvas-like painting methods that actually build vertices.

The goal is minimally invasive rendering for the performance monitor.

The methods in this class are intended to be used by |DlStopwatchVisualizer| only. The rationale is the creating lines, rectangles, and paths (while OK for general apps) would cause non-trivial work for the performance monitor due to tessellation per-frame.

Note

A goal of this class was to make updating the performance monitor (and keeping it in sync with the |SkStopwatchVisualizer|) as easy as possible (i.e. not having to do triangle-math).

Definition at line 47 of file stopwatch_dl.h.

Constructor & Destructor Documentation

DlVertexPainter()

flutter::DlVertexPainter::DlVertexPainter	(	std::vector< DlPoint > &	vertices_storage,
		std::vector< DlColor > &	color_storage
	)

Definition at line 123 of file stopwatch_dl.cc.

    : vertices_(vertices_storage), colors_(color_storage) {}

Member Function Documentation

DrawRect()

void flutter::DlVertexPainter::DrawRect	(	const DlRect &	rect,
		const DlColor &	color
	)

Draws a rectangle with the given color to a buffer.

Definition at line 127 of file stopwatch_dl.cc.

                                                                       {
  const DlScalar left = rect.GetLeft();
  const DlScalar top = rect.GetTop();
  const DlScalar right = rect.GetRight();
  const DlScalar bottom = rect.GetBottom();
 
  FML_DCHECK(6 + colors_offset_ <= vertices_.size());
  FML_DCHECK(6 + colors_offset_ <= colors_.size());
 
  // Draw 6 vertices representing 2 triangles.
  vertices_[vertices_offset_++] = DlPoint(left, top);      // tl tr
  vertices_[vertices_offset_++] = DlPoint(right, top);     //    br
  vertices_[vertices_offset_++] = DlPoint(right, bottom);  //
  vertices_[vertices_offset_++] = DlPoint(right, bottom);  // tl
  vertices_[vertices_offset_++] = DlPoint(left, bottom);   // bl br
  vertices_[vertices_offset_++] = DlPoint(left, top);      //
  for (size_t i = 0u; i < 6u; i++) {
    colors_[colors_offset_++] = color;
  }
}

References FML_DCHECK, impeller::TRect< T >::GetBottom(), impeller::TRect< T >::GetLeft(), impeller::TRect< T >::GetRight(), impeller::TRect< T >::GetTop(), and i.

Referenced by flutter::DlStopwatchVisualizer::Visualize().

IntoVertices()

std::shared_ptr< DlVertices > flutter::DlVertexPainter::IntoVertices

(

const DlRect &

bounds_rect

)

Converts the buffered vertices into a |DlVertices| object.

Note

This method clears the buffer.

Definition at line 148 of file stopwatch_dl.cc.

                               {
  return DlVertices::Make(
      /*mode=*/DlVertexMode::kTriangles,
      /*vertex_count=*/vertices_.size(),
      /*vertices=*/vertices_.data(),
      /*texture_coordinates=*/nullptr,
      /*colors=*/colors_.data(),
      /*index_count=*/0,
      /*indices=*/nullptr,
      /*bounds=*/&bounds_rect);
}

References flutter::kTriangles, and flutter::DlVertices::Make().

Referenced by flutter::DlStopwatchVisualizer::Visualize().

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

• flow/stopwatch_dl.h
• flow/stopwatch_dl.cc