Basic 2D rendering utility. More...

#include <LPainter.h>

Inheritance diagram for LPainter:

Classes
struct	TextureParams
	Parameters required for bindTextureMode(). More...

Public Member Functions
void	bindTextureMode (const TextureParams &params) noexcept
	Switches to texture mode.

void	bindColorMode () noexcept
	Switches to color mode.

void	drawBox (const LBox &box) noexcept
	Draws a texture or color box on the screen based on the current rendering mode.

void	drawRect (const LRect &rect) noexcept
	Draws a texture or color rect on the screen based on the current rendering mode.

void	drawRegion (const LRegion &region) noexcept
	Draws a texture or color region on the screen based on the current rendering mode.

void	enableCustomTextureColor (bool enabled) noexcept
	Enables or disables a custom texture color.

bool	customTextureColorEnabled () const noexcept
	Checks if custom texture color is enabled.

bool	autoBlendFuncEnabled () const noexcept
	Checks if automatic blending function selection is enabled.

void	enableAutoBlendFunc (bool enabled) const noexcept
	Toggles automatic blending function selection.

void	setBlendFunc (const LBlendFunc &blendFunc) const noexcept
	Sets a custom blend function.

void	setAlpha (Float32 alpha) noexcept
	Sets the alpha value.

void	setColor (const LRGBF &color) noexcept
	Sets the color.

void	setColorFactor (Float32 r, Float32 g, Float32 b, Float32 a) noexcept
	Sets the color factor.

void	setColorFactor (const LRGBAF &factor) noexcept
	Sets the color factor.

void	setClearColor (Float32 r, Float32 g, Float32 b, Float32 a) noexcept
	Sets the clear color.

void	setClearColor (const LRGBAF &color) noexcept
	Set the clear color.

void	clearScreen () noexcept
	Clear the framebuffer.

void	setViewport (const LRect &rect) noexcept
	Sets the viewport.

void	setViewport (Int32 x, Int32 y, Int32 w, Int32 h) noexcept
	Sets the viewport.

void	bindFramebuffer (LFramebuffer *framebuffer) noexcept
	Binds the specified framebuffer for rendering.

LFramebuffer *	boundFramebuffer () const noexcept
	Retrieves the currently bound framebuffer.

void	bindProgram () noexcept
	Bind the internal LPainter program.

Detailed Description

Basic 2D rendering utility.

The LPainter class offers essential methods for 2D rendering without the need to use OpenGL functions directly.
It can draw solid colors and textures with custom clipping, scaling, blending effects, and transforms.

Each LOutput has its own LPainter, accessible via LOutput::painter().

Note: While LPainter provides convenience, it's not mandatory. You have the flexibility to use OpenGL functions and your custom shaders if preferred, or leverage the efficiency of rendering provided by the LScene and LView classes.

Coordinate System

When specifying the destination rectangle for your painting operations, use compositor-global coordinates, which operate with surface units.
LPainter automatically scales and transforms the content for you, considering the scale factor/transform of the texture you are drawing and the scale factor/transform of the destination framebuffer.

The coordinate space in which the content is rendered aligns with that used to arrange outputs.
For example, to paint something in the upper-left corner of an LOutput, consider the LOutput::pos().

Note: When rendering into an LRenderBuffer, also consider its position, similar to how you handle outputs.

Class Documentation

◆ Louvre::LPainter::TextureParams

struct Louvre::LPainter::TextureParams

Parameters required for bindTextureMode().

This struct provides all the necessary parameters to map a texture into the current destination framebuffer.

Class Members
LTexture *	texture	Texture to be drawn.
LPoint	pos	Position of the texture (destination rect) in compositor-global coordinates.
LRectF	srcRect	Subrect of the texture to be mapped in surface units. Coordinates should be specified in the space generated after applying the scale factor and transformation to the texture buffer.
LSize	dstSize	Destination size of the source rect in surface units.
LTransform	srcTransform { LTransform::Normal }	Transform already applied to the texture. For example, if the texture is rotated 90 degrees counterclockwise and you want to display it in a normal orientation, use LTransform::Rotated90 and LPainter will apply the inverse transform (LTransform::Rotated270). If you don't want to apply any transform use LTransform::Normal.
Float32	srcScale { 1.f }	Scale factor of the texture.

Member Function Documentation

◆ bindTextureMode()

void bindTextureMode ( const TextureParams & params )

noexcept

Switches to texture mode.

This method maps a texture to the compositor-global space, enabling subsequent drawing of specific sub-rectangles using drawBox(), drawRect() or drawRegion().

Parameters

params Parameters required to map the texture.

◆ bindColorMode()

void bindColorMode ( )

noexcept

Switches to color mode.

In color mode, drawBox(), drawRect() and drawRegion() can be used to draw rectagles of the specified color.

The color is set using setColor() and setAlpha().

◆ drawBox()

void drawBox ( const LBox & box )

noexcept

Draws a texture or color box on the screen based on the current rendering mode.

Parameters

box	The box to be drawn in compositor-global coordinates.

◆ drawRect()

void drawRect ( const LRect & rect )

noexcept

Draws a texture or color rect on the screen based on the current rendering mode.

Parameters

rect	The rect to be drawn in compositor-global coordinates.

◆ drawRegion()

void drawRegion ( const LRegion & region )

noexcept

Draws a texture or color region on the screen based on the current rendering mode.

Parameters

region The region to be drawn in compositor-global coordinates.

◆ enableCustomTextureColor()

void enableCustomTextureColor ( bool enabled )

noexcept

Enables or disables a custom texture color.

When enabled, the bound texture RGB values are replaced by the color set with setColor().

◆ customTextureColorEnabled()

bool customTextureColorEnabled ( ) const

noexcept

Checks if custom texture color is enabled.

See also: enableCustomTextureColor().

Returns: true if custom texture color is enabled, otherwise false.

◆ autoBlendFuncEnabled()

bool autoBlendFuncEnabled ( ) const

noexcept

Checks if automatic blending function selection is enabled.

See also: enable enableAutoBlendFunc().

◆ enableAutoBlendFunc()

void enableAutoBlendFunc ( bool enabled ) const

noexcept

Toggles automatic blending function selection.

When enabled, LPainter will automatically select the appropriate OpenGL blend function mode based on whether the bound texture uses premultiplied alpha or not (see LTexture::premultipliedAlpha()).

When disabled, LPainter will use the blend function set with setBlendFunc().

Enabled by default.

◆ setBlendFunc()

void setBlendFunc ( const LBlendFunc & blendFunc ) const

noexcept

Sets a custom blend function.

Setting a custom blend function can be useful for masking or other sophisticated blending effects.

To make LPainter use this blend function, the auto blend function must be disabled, see enableAutoBlendFunc().

◆ setAlpha()

void setAlpha ( Float32 alpha )

noexcept

Sets the alpha value.

In texture mode, the texture alpha value is multiplied by this value.
In color mode, this value becomes the alpha value of the color.

Parameters

alpha The alpha value to be set.

◆ setColor()

void setColor ( const LRGBF & color )

noexcept

Sets the color.

In texture mode and if customTextureColorEnabled() is enabled, this value replaces the texture RGB values while keeping the alpha intact.
If color mode, this is the color to be drawn. See setAlpha().

Parameters

color The color to be set.

◆ setColorFactor() [1/2]

void setColorFactor	(	Float32	r,
		Float32	g,
		Float32	b,
		Float32	a
	)

noexcept

Sets the color factor.

This method multiplies each component of the source color by the specified factor.

Note: Setting all components to 1.0 disables the effect.

Parameters

r	The value of the red component (range: [0.0, 1.0]).
g	The value of the green component (range: [0.0, 1.0]).
b	The value of the blue component (range: [0.0, 1.0]).
a	The value of the alpha component (range: [0.0, 1.0]).

◆ setColorFactor() [2/2]

void setColorFactor ( const LRGBAF & factor )

noexcept

Sets the color factor.

This method multiplies each component of the source color by the specified factor.

Note: Setting all components to 1.0 disables the effect.

Parameters

factor The color factor to be set.

◆ setClearColor() [1/2]

void setClearColor	(	Float32	r,
		Float32	g,
		Float32	b,
		Float32	a
	)

noexcept

Sets the clear color.

This method sets the clear color used when calling clearScreen().

Parameters

r	Value of the red component (range [0.0, 1.0]).
g	Value of the green component (range [0.0, 1.0]).
b	Value of the blue component (range [0.0, 1.0]).
a	Value of the alpha component (range [0.0, 1.0]).

◆ setClearColor() [2/2]

void setClearColor ( const LRGBAF & color )

noexcept

Set the clear color.

This method sets the clear color used when calling clearScreen().

◆ clearScreen()

void clearScreen ( )

noexcept

Clear the framebuffer.

This method clears the bound framebuffer using the color set with setClearColor().

◆ setViewport() [1/2]

void setViewport ( const LRect & rect )

noexcept

Sets the viewport.

Note: Do not use this method unless you are working with your own shaders/programs.

◆ setViewport() [2/2]

void setViewport	(	Int32	x,
		Int32	y,
		Int32	w,
		Int32	h
	)

noexcept

Sets the viewport.

Note: Do not use this method unless you are working with your own shaders/programs.

◆ bindFramebuffer()

void bindFramebuffer ( LFramebuffer * framebuffer )

noexcept

Binds the specified framebuffer for rendering.

This method binds the provided framebuffer for rendering, allowing subsequent rendering operations to be performed on it.

Note: Output framebuffers are automatically bound prior a LOutput::paintGL() event.

Parameters

framebuffer The framebuffer to be bound.

◆ boundFramebuffer()

LFramebuffer * boundFramebuffer ( ) const

noexcept

Retrieves the currently bound framebuffer.

This method returns a pointer to the currently bound framebuffer for rendering.

Returns: A pointer to the currently bound framebuffer.

◆ bindProgram()

void bindProgram ( )

noexcept

Bind the internal LPainter program.

Note: This method should be used if you are working with your own OpenGL programs and want to use the LPainter methods again.

Classes

Public Member Functions

Detailed Description

Coordinate System

Class Documentation

◆ Louvre::LPainter::TextureParams

Member Function Documentation

◆ bindTextureMode()

◆ bindColorMode()

◆ drawBox()

◆ drawRect()

◆ drawRegion()

◆ enableCustomTextureColor()

◆ customTextureColorEnabled()

◆ autoBlendFuncEnabled()

◆ enableAutoBlendFunc()

◆ setBlendFunc()

◆ setAlpha()

◆ setColor()

◆ setColorFactor() [1/2]

◆ setColorFactor() [2/2]

◆ setClearColor() [1/2]

◆ setClearColor() [2/2]

◆ clearScreen()

◆ setViewport() [1/2]

◆ setViewport() [2/2]

◆ bindFramebuffer()

◆ boundFramebuffer()

◆ bindProgram()