Canvas

Struct · namespace System.Ui · Since 0.32

struct Canvas

Draws into an Image: everything is clipped to Clip, colors with an alpha below 255 are blended with what is already there, and the edges of rounded rectangles, circles and lines are smooth. A canvas shares the pixels of its image (an Image holds them by reference), so drawing changes the image.

var image = Image.Create(200, 100);
var canvas = Canvas.Create(image);
canvas.Clear(Color.White());
canvas.FillRoundRect(Rect.Create(10, 10, 120, 30), 6, Color.FromRgb(40, 110, 220));
canvas.Text(Font.Fixed7x13(), 20, 18, "Hello", Color.White());

Fields

Name	Description
Target	The image that is drawn into.
Clip	Only pixels inside this rectangle are changed.

Target

Image Target

The image that is drawn into.

Clip

Rect Clip

Only pixels inside this rectangle are changed.

Static methods

Name	Description
Create	A canvas for the whole image.

Create

static Canvas Create(Image target)

A canvas for the whole image.

Methods

Name	Description
SetClip	Restricts drawing to a rectangle (within the image).
Clear	Fills the whole image (ignoring the clip rectangle) with one color.
Blend	Blends one pixel: coverage 0 (nothing) to 255 (the color with its own alpha).
FillRect	Fills a rectangle.
StrokeRect	Draws the outline of a rectangle, width pixels thick, inside the rectangle.
FillRoundRect	Fills a rectangle with rounded corners of the given radius (smooth edges).
StrokeRoundRect	Draws the outline of a rounded rectangle, width pixels thick, inside the rectangle.
FillCircle	Fills a circle (smooth edge); the center may lie between pixels.
Line	Draws a line width pixels thick with round ends (smooth edges); coordinates may lie between pixels.
Text	Draws text with its top left corner at (x, y) and returns its width.
DrawImage	Draws an image with its top left corner at (x, y), blended by the alpha of its pixels.

SetClip

void SetClip(Rect clip)

Restricts drawing to a rectangle (within the image).

Clear

void Clear(Color color)

Fills the whole image (ignoring the clip rectangle) with one color.

Blend

void Blend(int x, int y, Color color, int coverage)

Blends one pixel: coverage 0 (nothing) to 255 (the color with its own alpha).

FillRect

void FillRect(Rect rect, Color color)

Fills a rectangle.

StrokeRect

void StrokeRect(Rect rect, int width, Color color)

Draws the outline of a rectangle, width pixels thick, inside the rectangle.

FillRoundRect

void FillRoundRect(Rect rect, int radius, Color color)

Fills a rectangle with rounded corners of the given radius (smooth edges).

StrokeRoundRect

void StrokeRoundRect(Rect rect, int radius, int width, Color color)

Draws the outline of a rounded rectangle, width pixels thick, inside the rectangle.

FillCircle

void FillCircle(double cx, double cy, double radius, Color color)

Fills a circle (smooth edge); the center may lie between pixels.

Line

void Line(double x0, double y0, double x1, double y1, double width, Color color)

Draws a line width pixels thick with round ends (smooth edges); coordinates may lie between pixels.

Text

int Text(Font font, int x, int y, StringSlice text, Color color)

Draws text with its top left corner at (x, y) and returns its width. Line ends are not interpreted.

DrawImage

void DrawImage(Image image, int x, int y)

Draws an image with its top left corner at (x, y), blended by the alpha of its pixels.