GlCanvas

A class for the rendering graphic elements with a GL raster engine. More...

Inheritance diagram for GlCanvas:

Collaboration diagram for GlCanvas:

Public Member Functions
Result	target (int32_t id, uint32_t w, uint32_t h) noexcept
	Sets the drawing target for rasterization. More...
Public Member Functions inherited from Canvas
std::list< Paint * > &	paints () noexcept
	Returns the list of the paints that currently held by the Canvas. More...
virtual Result	push (std::unique_ptr< Paint > paint) noexcept
	Passes drawing elements to the Canvas using Paint objects. More...
virtual Result	clear (bool free=true) noexcept
	Clear the internal canvas resources that used for the drawing. More...
virtual Result	update (Paint *paint=nullptr) noexcept
	Request the canvas to update the paint objects. More...
virtual Result	draw () noexcept
	Requests the canvas to draw the Paint objects. More...
virtual Result	viewport (int32_t x, int32_t y, int32_t w, int32_t h) noexcept
	Sets the drawing region in the canvas. More...
virtual Result	sync () noexcept
	Guarantees that drawing task is finished. More...

Static Public Member Functions
static std::unique_ptr< GlCanvas >	gen () noexcept
	Creates a new GlCanvas object. More...

Detailed Description

A class for the rendering graphic elements with a GL raster engine.

Since

0.14

Member Function Documentation

gen()

static std::unique_ptr<GlCanvas> gen ( )

staticnoexcept

Creates a new GlCanvas object.

Returns

A new GlCanvas object.

Since

0.14

target()

Result target ( int32_t  id, uint32_t  w, uint32_t  h  )

noexcept

Sets the drawing target for rasterization.

This function specifies the drawing target where the rasterization will occur. It can target a specific framebuffer object (FBO) or the main surface.

Parameters

[in]	id	The GL target ID, usually indicating the FBO ID. A value of 0 specifies the main surface.
[in]	w	The width (in pixels) of the raster image.
[in]	h	The height (in pixels) of the raster image.

Return values

Result::InsufficientCondition	if the canvas is performing rendering. Please ensure the canvas is synced.
Result::NonSupport	In case the gl engine is not supported.

See also

Canvas::viewport()

Canvas::sync()

Note

Currently, this only allows the GL_RGBA8 color space format.

Experimental API