flutter::DlVertexPainter Class Reference

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

#include <stopwatch_dl.h>

Public Member Functions
void	DrawRect (const SkRect &rect, const DlColor &color)
	Draws a rectangle with the given color to a buffer. More...
std::shared_ptr< DlVertices >	IntoVertices ()

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 39 of file stopwatch_dl.h.

Member Function Documentation

DrawRect()

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

Draws a rectangle with the given color to a buffer.

Definition at line 112 of file stopwatch_dl.cc.

                                                                       {
  // Draw 6 vertices representing 2 triangles.
  auto const left = rect.x();
  auto const top = rect.y();
  auto const right = rect.right();
  auto const bottom = rect.bottom();
 
  auto const vertices = std::array<SkPoint, 6>{
      SkPoint::Make(left, top),      // tl tr
      SkPoint::Make(right, top),     //    br
      SkPoint::Make(right, bottom),  //
      SkPoint::Make(right, bottom),  // tl
      SkPoint::Make(left, bottom),   // bl br
      SkPoint::Make(left, top)       //
  };
 
  auto const colors = std::array<DlColor, 6>{
      color,  // tl tr
      color,  //    br
      color,  //
      color,  // tl
      color,  // bl br
      color   //
  };
 
  vertices_.insert(vertices_.end(), vertices.begin(), vertices.end());
  colors_.insert(colors_.end(), colors.begin(), colors.end());
}

IntoVertices()

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

(

)

Converts the buffered vertices into a |DlVertices| object.

Note

This method clears the buffer.

Definition at line 141 of file stopwatch_dl.cc.

                                                        {
  auto const result = DlVertices::Make(
      /*mode=*/DlVertexMode::kTriangles,
      /*vertex_count=*/vertices_.size(),
      /*vertices=*/vertices_.data(),
      /*texture_coordinates=*/nullptr,
      /*colors=*/colors_.data());
  vertices_.clear();
  colors_.clear();
  return result;
}

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

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