Shapes and geometry

Platform-agnostic tessellation of rounded rectangles, ellipses, polygons, strokes, arcs, gradients and soft shadows into anti-aliased triangle meshes (GuiMesh). More...

Classes
struct	GuiPoint
	A 2D point in design-canvas pixels. More...
struct	GuiRect
	An axis-aligned rectangle (top-left origin) in design-canvas pixels. More...
struct	GuiCorners
	Per-corner radii, in the order top-left, top-right, bottom-right, bottom-left. More...
struct	GuiFill
	A solid color or a two-color linear gradient. More...
struct	GuiPath
	A closed outline made of straight lines and cubic Beziers, in whatever units the caller likes. More...
class	GuiMesh
	Accumulates shapes as a triangle list of MeshVertex. More...
struct	GuiMeshKey
	Everything that decides what a shape's triangles are. More...
class	GuiSharedMesh
	One cached mesh. More...
class	GuiMeshCache
	Static, since there is one video backend. More...
class	GuiShape
	A code-drawn shape: a rectangle (optionally rounded) or ellipse with a fill, outline and shadow, and no image assets. More...
struct	GuiTheme
	Colors, metrics and the style recipes built from them. More...

Enumerations
enum class	STROKE { STROKE::INSIDE , STROKE::CENTRE , STROKE::OUTSIDE }
	Where a stroke sits relative to the shape's geometric edge. More...
enum class	SHAPE { SHAPE::RECTANGLE , SHAPE::ELLIPSE }
	Basic shape kinds a paint can be applied to. More...
enum class	SHAPE_STATE { NORMAL , SHAPE_STATE::FOCUSED , PRESSED , DISABLED }
	The states a styled shape distinguishes. More...

Functions
std::vector< std::vector< GuiPoint > >	GuiFlattenPath (const GuiPath &path, float scale, float tolerance=0.15f)
	Turns a path into one polygon per contour, multiplied by scale.
GuiRect	GuiPathBounds (const GuiPath &path, float scale=1.0f)
	Gets the bounding box of a path's points (control points included, so it can be a little larger than the drawn curve), multiplied by scale
std::vector< GuiPoint >	GuiRoundRectPolygon (const GuiRect &r, float radius, float angleDeg, float tolerance=0.15f)
	A rounded rectangle as a convex polygon, rotated about its center.
PixelColor	GuiMixColor (PixelColor a, PixelColor b, float t)
	Blends two colors per channel (alpha included): t = 0 gives a, t = 1 gives b.
void	GuiAddPaintedShape (GuiMesh &mesh, SHAPE shape, const GuiRect &r, const GuiCorners &corners, const GuiPaint &paint)
	Adds a painted shape to a mesh: shadow first, then fill, then outline.

Variables
bool	hasFill
	The look of a shape: an optional fill, an optional outline and an optional shadow or glow.

Detailed Description

Platform-agnostic tessellation of rounded rectangles, ellipses, polygons, strokes, arcs, gradients and soft shadows into anti-aliased triangle meshes (GuiMesh).

Enumeration Type Documentation

SHAPE

enum class SHAPE

strong

Basic shape kinds a paint can be applied to.

Enumerator
RECTANGLE	Rectangle, with optional rounded corners (see GuiCorners)
ELLIPSE	Ellipse inscribed in the rectangle (a circle when it is square)

Definition at line 17 of file GuiPaint.h.

SHAPE_STATE

enum class SHAPE_STATE

strong

The states a styled shape distinguishes.

Enumerator
FOCUSED	Highlighted: under the cursor, or selected with the D-pad.

Definition at line 70 of file GuiPaint.h.

STROKE

enum class STROKE

strong

Where a stroke sits relative to the shape's geometric edge.

Enumerator
INSIDE	Entirely inside the edge (the shape keeps its size)
CENTRE	Centered on the edge.
OUTSIDE	Entirely outside the edge.

Definition at line 52 of file GuiGeometry.h.

Function Documentation

GuiAddPaintedShape()

void GuiAddPaintedShape	(	GuiMesh &	mesh,
		SHAPE	shape,
		const GuiRect &	r,
		const GuiCorners &	corners,
		const GuiPaint &	paint )

Adds a painted shape to a mesh: shadow first, then fill, then outline.

For SHAPE::ELLIPSE the corner radii are ignored; the shadow of an ellipse follows its outline.

Definition at line 218 of file GuiPaint.cpp.

GuiFlattenPath()

std::vector< std::vector< GuiPoint > > GuiFlattenPath	(	const GuiPath &	path,
		float	scale,
		float	tolerance = 0.15f )

Turns a path into one polygon per contour, multiplied by scale.

Curves are split until no part of the polygon is farther than tolerance from the true curve, so a flat stretch costs one segment and a tight corner costs more. A contour with fewer than 3 points is dropped.

Parameters

path	The path
scale	Multiplies every coordinate
tolerance	Largest allowed distance between the true curve and the polygon, in the scaled units

Definition at line 804 of file GuiGeometry.cpp.

GuiMixColor()

PixelColor GuiMixColor	(	PixelColor	a,
		PixelColor	b,
		float	t )

Blends two colors per channel (alpha included): t = 0 gives a, t = 1 gives b.

Definition at line 250 of file GuiPaint.cpp.

GuiPathBounds()

GuiRect GuiPathBounds	(	const GuiPath &	path,
		float	scale = 1.0f )

Gets the bounding box of a path's points (control points included, so it can be a little larger than the drawn curve), multiplied by scale

Definition at line 849 of file GuiGeometry.cpp.

GuiRoundRectPolygon()

std::vector< GuiPoint > GuiRoundRectPolygon	(	const GuiRect &	r,
		float	radius,
		float	angleDeg,
		float	tolerance = 0.15f )

A rounded rectangle as a convex polygon, rotated about its center.

Use it where a shape has to be tilted, or where several shapes should merge into one silhouette (draw each piece's outline stroke first and the fills after, and the joins disappear).

Parameters

r	Rectangle before rotation
radius	Corner radius (clamped to half the shorter side)
angleDeg	Rotation in degrees, clockwise on screen
tolerance	Largest allowed distance between the true curve and the polygon

Definition at line 742 of file GuiGeometry.cpp.

Variable Documentation

hasFill

bool hasFill

The look of a shape: an optional fill, an optional outline and an optional shadow or glow.

Setters chain, so a paint reads as a sentence: GuiPaint().gradient(top, bottom).stroke(2, edge).shadow(14, black, 0, 4) ! struct GuiPaint { GuiFill fill; /*!< Fill, used when hasFill. Whether the shape is filled.

Definition at line 28 of file GuiPaint.h.