An abstract class for managing graphical elements. More...

Inheritance diagram for Paint:

[legend]

Public Member Functions
Result	rotate (float degree) noexcept
	Sets the angle by which the object is rotated. More...

Result	scale (float factor) noexcept
	Sets the scale value of the object. More...

Result	translate (float x, float y) noexcept
	Sets the values by which the object is moved in a two-dimensional space. More...

Result	transform (const Matrix &m) noexcept
	Sets the matrix of the affine transformation for the object. More...

Matrix	transform () noexcept
	Gets the matrix of the affine transformation of the object. More...

Result	opacity (uint8_t o) noexcept
	Sets the opacity of the object. More...

Result	composite (std::unique_ptr< Paint > target, CompositeMethod method) noexcept
	Sets the composition target object and the composition method. More...

Result	blend (BlendMethod method) const noexcept
	Sets the blending method for the paint object. More...

TVG_DEPRECATED Result	bounds (float x, float y, float w, float h) const noexcept
	Gets the bounding box of the paint object before any transformation. More...

Result	bounds (float x, float y, float w, float h, bool transformed) const noexcept
	Gets the axis-aligned bounding box of the paint object. More...

Paint *	duplicate () const noexcept
	Duplicates the object. More...

uint8_t	opacity () const noexcept
	Gets the opacity value of the object. More...

CompositeMethod	composite (const Paint **target) const noexcept
	Gets the composition target object and the composition method. More...

BlendMethod	blend () const noexcept
	Gets the blending method of the object. More...

uint32_t	identifier () const noexcept
	Return the unique id value of the paint instance. More...

Detailed Description

An abstract class for managing graphical elements.

A graphical element in TVG is any object composed into a Canvas. Paint represents such a graphical object and its behaviors such as duplication, transformation and composition. TVG recommends the user to regard a paint as a set of volatile commands. They can prepare a Paint and then request a Canvas to run them.

Member Function Documentation

◆ blend() [1/2]

BlendMethod blend ( ) const

noexcept

Gets the blending method of the object.

Returns: The blending method

Note: Experimental API

◆ blend() [2/2]

Result blend ( BlendMethod method ) const

noexcept

Sets the blending method for the paint object.

The blending feature allows you to combine colors to create visually appealing effects, including transparency, lighting, shading, and color mixing, among others. its process involves the combination of colors or images from the source paint object with the destination (the lower layer image) using blending operations. The blending operation is determined by the chosen BlendMethod, which specifies how the colors or images are combined.

Parameters

[in] method The blending method to be set.

Return values

Result::Success when the blending method is successfully set.

Note: Experimental API

◆ bounds() [1/2]

TVG_DEPRECATED Result bounds	(	float *	x,
		float *	y,
		float *	w,
		float *	h
	)		const

noexcept

Gets the bounding box of the paint object before any transformation.

Parameters

[out]	x	The x coordinate of the upper left corner of the object.
[out]	y	The y coordinate of the upper left corner of the object.
[out]	w	The width of the object.
[out]	h	The height of the object.

Returns: Result::Success when succeed, Result::InsufficientCondition otherwise.

Note: The bounding box doesn't indicate the final rendered region. It's the smallest rectangle that encloses the object.

See also: Paint::bounds(float* x, float* y, float* w, float* h, bool transformed);

◆ bounds() [2/2]

Result bounds	(	float *	x,
		float *	y,
		float *	w,
		float *	h,
		bool	transformed
	)		const

noexcept

Gets the axis-aligned bounding box of the paint object.

In case transform is true, all object's transformations are applied first, and then the bounding box is established. Otherwise, the bounding box is determined before any transformations.

Parameters

[out]	x	The x coordinate of the upper left corner of the object.
[out]	y	The y coordinate of the upper left corner of the object.
[out]	w	The width of the object.
[out]	h	The height of the object.
[in]	transformed	If `true`, the paint's transformations are taken into account, otherwise they aren't.

Return values

Result::Success when succeed, Result::InsufficientCondition otherwise.

Note: The bounding box doesn't indicate the actual drawing region. It's the smallest rectangle that encloses the object.

◆ composite() [1/2]

CompositeMethod composite ( const Paint ** target ) const

noexcept

Gets the composition target object and the composition method.

Parameters

[out] target The paint of the target object.

Returns: The method used to composite the source object with the target.

Since: 0.5

◆ composite() [2/2]

Result composite	(	std::unique_ptr< Paint >	target,
		CompositeMethod	method
	)

noexcept

Sets the composition target object and the composition method.

Parameters

[in]	target	The paint of the target object.
[in]	method	The method used to composite the source object with the target.

Return values

Result::Success when succeed, Result::InvalidArguments otherwise.

◆ duplicate()

Paint* duplicate ( ) const

noexcept

Duplicates the object.

Creates a new object and sets its all properties as in the original object.

Returns: The created object when succeed, nullptr otherwise.

◆ identifier()

uint32_t identifier ( ) const

noexcept

Return the unique id value of the paint instance.

This method can be called for checking the current concrete instance type.

Returns: The type id of the Paint instance.

◆ opacity() [1/2]

uint8_t opacity ( ) const

noexcept

Gets the opacity value of the object.

Returns: The opacity value in the range [0 ~ 255], where 0 is completely transparent and 255 is opaque.

◆ opacity() [2/2]

Result opacity ( uint8_t o )

noexcept

Sets the opacity of the object.

Parameters

[in] o The opacity value in the range [0 ~ 255], where 0 is completely transparent and 255 is opaque.

Return values

Result::Success when succeed.

Note: Setting the opacity with this API may require multiple render pass for composition. It is recommended to avoid changing the opacity if possible.; ClipPath won't use the opacity value. (see: enum class CompositeMethod::ClipPath)

◆ rotate()

Result rotate ( float degree )

noexcept

Sets the angle by which the object is rotated.

The angle in measured clockwise from the horizontal axis. The rotational axis passes through the point on the object with zero coordinates.

Parameters

[in] degree The value of the angle in degrees.

Return values

Result::Success when succeed, Result::FailedAllocation otherwise.

◆ scale()

Result scale ( float factor )

noexcept

Sets the scale value of the object.

Parameters

[in] factor The value of the scaling factor. The default value is 1.

Return values

Result::Success when succeed, Result::FailedAllocation otherwise.

◆ transform() [1/2]

Matrix transform ( )

noexcept

Gets the matrix of the affine transformation of the object.

The values of the matrix can be set by the transform() API, as well by the translate(), scale() and rotate(). In case no transformation was applied, the identity matrix is returned.

Returns: The augmented transformation matrix.

Since: 0.4

◆ transform() [2/2]

Result transform ( const Matrix & m )

noexcept

Sets the matrix of the affine transformation for the object.

The augmented matrix of the transformation is expected to be given.

Parameters

[in] m The 3x3 augmented matrix.

Return values

Result::Success when succeed, Result::FailedAllocation otherwise.

◆ translate()

Result translate	(	float	x,
		float	y
	)

noexcept

Sets the values by which the object is moved in a two-dimensional space.

The origin of the coordinate system is in the upper left corner of the canvas. The horizontal and vertical axes point to the right and down, respectively.

Parameters

[in]	x	The value of the horizontal shift.
[in]	y	The value of the vertical shift.

Return values

Result::Success when succeed, Result::FailedAllocation otherwise.

Public Member Functions

Detailed Description

Member Function Documentation

◆ blend() [1/2]

◆ blend() [2/2]

◆ bounds() [1/2]

◆ bounds() [2/2]

◆ composite() [1/2]

◆ composite() [2/2]

◆ duplicate()

◆ identifier()

◆ opacity() [1/2]

◆ opacity() [2/2]

◆ rotate()

◆ scale()

◆ transform() [1/2]

◆ transform() [2/2]

◆ translate()