Graphics output

Functions
void	drawRect (float center_x, float center_y, float width, float height, const Brush &brush)
void	drawBezier (float *ep1, float *cp1, float *cp2, float *ep2, const Brush &brush)
void	drawLine (float x1, float y1, float x2, float y2, const Brush &brush)
void	drawDisk (float cx, float cy, float radius, const Brush &brush)
void	drawSector (float cx, float cy, float radius1, float radius2, float start_angle, float end_angle, const Brush &brush)
bool	setFont (std::string fontname)
void	drawText (float pos_x, float pos_y, float size, const std::string &text, const Brush &brush)
void	setOrientation (float angle)
void	setScale (float sx, float sy)
void	resetPose ()

Detailed Description

Function Documentation

drawBezier()

void drawBezier	(	float *	ep1,
		float *	cp1,
		float *	cp2,
		float *	ep2,
		const Brush &	brush )

Draws a bezier segment.

Draws a 3rd order bezier segment between two end-points on the canvas, using two intermediate control points to distort the curve. The outline attributes are specified in the brush parameter.

Parameters

ep1	is an array containing the x and y coordinates of the first end point, in canvas units.
cp1	is an array containing the x and y coordinates of the first control point, in canvas units.
cp2	is an array containing the x and y coordinates of the second control point, in canvas units.
ep2	is an array containing the x and y coordinates of the second end point, in canvas units.
brush	specifies the drawing attributes to use for the outline and fill of the shape.

See also

Brush

drawDisk()

void drawDisk	(	float	cx,
		float	cy,
		float	radius,
		const Brush &	brush )

Draws a disk.

Draws a disk (or circle, if fill opacity is set to 0) of certain radius and centered at (cx, cy). The outline and fill attributes are specified in the brush parameter.

Parameters

cx	is the x coordinate of the center of the disk in canvas units.
cy	is the y coordinate of the center of the disk in canvas units.
radius	is the radius of the disk in canvas units.
brush	specifies the drawing attributes to use for the outline and fill of the shape.

See also

Brush

drawLine()

void drawLine	(	float	x1,
		float	y1,
		float	x2,
		float	y2,
		const Brush &	brush )

Draws a line segment.

Draws a linear segment between two points on the canvas. The outline attributes are specified in the brush parameter.

Parameters

x1	is the x coordinate of the first point in canvas units.
y1	is the y coordinate of the first point in canvas units.
x2	is the x coordinate of the second point in canvas units.
y2	is the y coordinate of the second point in canvas units.
brush	specifies the drawing attributes to use for the outline and fill of the shape.

See also

Brush

drawRect()

void drawRect	(	float	center_x,
		float	center_y,
		float	width,
		float	height,
		const Brush &	brush )

Draws a rectangle.

Draws a rectangle of size width X height, centered at (center_x, center_y). The shape outline and fill attributes are provided in the brush parameter.

Parameters

center_x	is the x coordinate of the rectangle center in canvas units.
center_y	is the y coordinate of the rectangle center in canvas units.
width	is the horizontal size of the rectangle center in canvas units.
height	is the vertical size of the rectangle center in canvas units.
brush	specifies the drawing attributes to use for the outline and fill of the shape.

See also

Brush

drawSector()

void drawSector	(	float	cx,
		float	cy,
		float	radius1,
		float	radius2,
		float	start_angle,
		float	end_angle,
		const Brush &	brush )

Draws a sector of a disk.

Draws a sector of a disk between an inner and outer radius and two angles. The outline and fill attributes are specified in the brush parameter.

// In the draw callback function:
graphics::Brush br;
br.fill_color[0] = 1.0f;
br.fill_color[1] = 0.1f;
br.fill_color[2] = 0.0f;
br.fill_secondary_color[0] = 0.0f;
br.fill_secondary_color[1] = 0.2f;
br.fill_secondary_color[2] = 1.f;
br.gradient = true;
br.gradient_dir_u = 1.0f;
br.gradient_dir_v = 0.0f;
 
graphics::drawSector(20, 20, 5, 10, 0, 90, br);

Parameters

cx	is the x coordinate of the center of the disk sector in canvas units.
cy	is the y coordinate of the center of the disk sector in canvas units.
radius1	is the inner radius of the disk sector in canvas units.
radius2	is the outer radius of the disk sector in canvas units.

drawText()

void drawText	(	float	pos_x,
		float	pos_y,
		float	size,
		const std::string &	text,
		const Brush &	brush )

Draws a string of text at a user-provided location on the canvas, using the current font.

The function displays the glyphs for the text provided, in a left-aligned manner. The coordinates passed to the function correspond to the lower left corner of the text box and the height of the glyphs is indicated by the size parameter. If there is no active font (or the setFont function failed), no text is drawn.

Parameters

pos_x	is the horizontal coordinate of the lower left corner of the text in canvas units.
pos_y	is the vertical coordinate of the lower left corner of the text in canvas units.
size	is the glyph height of the text to be drawn.
text	is the string of text to display.
brush	contains the drawing attributes. Only the fill parameters of the provided brush are used for drawing, including any gradient.

See also

setFont

resetPose()

void resetPose

(

)

Restores both the orientation and scaling to their default values for subsequent draw calls.

setFont()

bool setFont

(

std::string

fontname

)

Sets the current font for text rendering.

Notifies the SGG engine to prepare and make current the font typeface in the filename supplied as argument. If the font is not already loaded into SGG, it loads the SGG and builds all necessary information for it. If the font name supplied does not correspond to a valid path to a TrueType typeface, the operation is silently aborted and no font is loaded or made active for text rendering. After loading the font, it is made current and all subsequent text drawing calls use this font for text rendering. If the font is already loaded into SGG, it is just made active for rendering. This operation does not incur any measurable overhead, as all resource allocation and convesion processes occur once, during the first call to load a specific font.

Parameters

fontname

is a valid path to the filename of the TrueType font (.ttf extension) to use.

Returns

true if the operation was successful, false otherwise.

See also

drawText

setOrientation()

void setOrientation

(

float

angle

)

Sets the current orientation that all subsequent draw calls will use for the displayed shapes.

SGG maintains a current orientation (default value 0.0f - no rotation) according to which it displays the shape of draw calls. Once set, the orientation is respected by all subsequent draw calls, until set to a new value or reset via a call to resetPose(). The rotation of the drawn shape in accordance with the orientation value occurs using a pivot point specific to the drawn shape. For rectangles, disks and sections, the pivot point is their center. For text, it is the lower left corner of the text bounds. Line segments are not rotated, since it is simpler to redefine their end-points.

Parameters

angle

is the angle of rotation for the shapes to draw in degrees. Positive angles correspond to counter-clockwise rotations.

setScale()

void setScale	(	float	sx,
		float	sy )

Sets the current scale that all subsequent draw calls will use for the displayed shapes.

SGG maintains a current scale (default value 1.0f - no scaling) according to which it displays the shape of draw calls. Once set, the scale is respected by all subsequent draw calls, until set to a new value or reset via a call to resetPose().

The scaling is defined by two scaling factors, one for each dimension of the shape. Setting an equal value for both parameters corresponds to a uniform scale (no distortion). Scaling factors greater than 1 mean shape magnification, while values less than 1 result in shrinking. Never set the scaling factor to 0.

The change of scale of the drawn shape along its X and Y dimension is performed prior to the rotation, using a pivot point specific to the drawn shape. For rectangles, disks and sections, the pivot point is their center. For text, it is the lower left corner of the text bounds. Line segments are not scaled, since it is simpler to redefine their end-points.

Parameters

sx	is the scale factor along the local X axis of the shape. 1 means no scaling.
sy	is the scale factor along the local Y axis of the shape. 1 means no scaling.