Linear gradient (horizontal, vertical, or skewed). More...

#include <gradient.h>

Inheritance diagram for roo_display::LinearGradient:

Collaboration diagram for roo_display::LinearGradient:

Public Member Functions
	LinearGradient (Point origin, float dx, float dy, ColorGradient gradient, Box extents=Box::MaximumBox())
	Create a linear gradient.

Box	extents () const override
	Return the bounding box encompassing all pixels that need to be drawn.

void	readColors (const int16_t x, const int16_t y, uint32_t count, Color *result) const override
	Read colors for the given points.

bool	readColorRect (int16_t xMin, int16_t yMin, int16_t xMax, int16_t yMax, Color *result) const override
	Read colors for a rectangle.

Public Member Functions inherited from roo_display::Rasterizable
void	readColorsMaybeOutOfBounds (const int16_t x, const int16_t y, uint32_t count, Color *result, Color out_of_bounds_color=color::Transparent) const
	Read colors for points that may be out of bounds.

std::unique_ptr< PixelStream >	createStream () const override
	Default `createStream()` using `readColors()`.

std::unique_ptr< PixelStream >	createStream (const Box &bounds) const override
	Default `createStream()` for a clipped box using `readColors()`.

Public Member Functions inherited from roo_display::Streamable
virtual TransparencyMode	getTransparencyMode () const
	Return the transparency mode for pixels in this stream.

Public Member Functions inherited from roo_display::Drawable
virtual	~Drawable ()

virtual Box	anchorExtents () const
	Return the bounds used for alignment.

Additional Inherited Members
Static Public Member Functions inherited from roo_display::Drawable
static const Drawable *	Empty ()
	A singleton representing a no-op drawable with no bounding box.

Protected Member Functions inherited from roo_display::Rasterizable
void	drawTo (const Surface &s) const override
	Default `drawTo()` using `readColors()`.

Detailed Description

Linear gradient (horizontal, vertical, or skewed).

Definition at line 119 of file gradient.h.

Constructor & Destructor Documentation

◆ LinearGradient()

roo_display::LinearGradient::LinearGradient	(	Point	origin,
		float	dx,
		float	dy,
		ColorGradient	gradient,
		Box	extents = `Box::MaximumBox()`
	)

Create a linear gradient.

Color value is computed as: $(x - origin.x) * dx + (y - origin.y) * dy$ . Use dx = 0 for vertical, dy = 0 for horizontal gradients. No anti-aliasing is performed; for skewed gradients keep a minimum node spacing of $\sqrt{1/dx^2 + 1/dy^2}$ .