Renderer

Functions
int	tiger_renderer_create (tiger_renderer **tr)
int	tiger_renderer_set_buffer (tiger_renderer *tr, unsigned char *ptr, int width, int height, int stride, int swap_rgb)
int	tiger_renderer_set_quality (tiger_renderer *tr, double quality)
int	tiger_renderer_destroy (tiger_renderer *tr)
int	tiger_renderer_set_surface_clear_color (tiger_renderer *tr, int clear, double r, double g, double b, double a)
int	tiger_renderer_add_event (tiger_renderer *tr, const kate_info *ki, const kate_event *ev)
int	tiger_renderer_update (tiger_renderer *tr, kate_float t, int track)
int	tiger_renderer_seek (tiger_renderer *tr, kate_float target)
int	tiger_renderer_render (tiger_renderer *tr)
int	tiger_renderer_is_dirty (const tiger_renderer *tr)
int	tiger_renderer_set_default_font_description (tiger_renderer *tr, const char *desc)
int	tiger_renderer_set_default_font (tiger_renderer *tr, const char *font)
int	tiger_renderer_set_default_font_size (tiger_renderer *tr, double size)
int	tiger_renderer_set_default_font_color (tiger_renderer *tr, double r, double g, double b, double a)
int	tiger_renderer_set_default_background_fill_color (tiger_renderer *tr, double r, double g, double b, double a)
int	tiger_renderer_set_default_font_effect (tiger_renderer *tr, tiger_font_effect effect, double strength)
int	tiger_renderer_enable_caching (tiger_renderer *tr, int enable)

Detailed Description

Function Documentation

int tiger_renderer_add_event	(	tiger_renderer *	tr,
		const kate_info *	ki,
		const kate_event *	ev
	)

Adds an event to the renderer

Parameters

tr	the Tiger renderer to add the event to
ki	the kate_info for the stream this events belongs to
ev	the event to add to the renderer

Returns

0 success

TIGER_E_* error

References TIGER_E_INVALID_PARAMETER, and TIGER_E_OUT_OF_MEMORY.

int tiger_renderer_create

(

tiger_renderer **

tr

)

Creates a new Tiger renderer

Parameters

tr	where to store a pointer to the newly created renderer

Returns

0 success

TIGER_E_* error

References TIGER_E_INVALID_PARAMETER, and TIGER_E_OUT_OF_MEMORY.

int tiger_renderer_destroy

(

tiger_renderer *

tr

)

Destroys a previously initialized Tiger renderer

Parameters

tr	the Tiger renderer to clear

Returns

0 success

TIGER_E_* error

References TIGER_E_INVALID_PARAMETER.

int tiger_renderer_enable_caching	(	tiger_renderer *	tr,
		int	enable
	)

Enables or disables internal caching of text layouts

Parameters

tr	the Tiger renderer for which to enable or disable caching
enable	whether to enable or disable caching

Returns

0 success

TIGER_E_* error

int tiger_renderer_is_dirty

(

const tiger_renderer *

tr

)

Checks whether the Tiger renderer is dirty or not (eg, whether rendering a frame now would yield a different frame from the previous frame).

Parameters

tr	the Tiger renderer to query

Returns

0 success, and the Tiger renderer is not dirrty

!0 success, the Tiger renderer is dirty

Note

The client code may choose not to call tiger_renderer_render if the renderer is not dirty as an optimization. However, care should be taken if the buffer the frame was rendered onto was changed (eg, if a new video frame was drawn onto it); in this case, a new frame should be rendered on top of the video, even if the Tiger frame would be the same as the previous frame, as it would have been erased by the video.

int tiger_renderer_render

(

tiger_renderer *

tr

)

Renders the current state of the renderer

Parameters

tr	the Tiger renderer to update

Returns

0 success

TIGER_E_* error

References TIGER_E_INVALID_PARAMETER.

int tiger_renderer_seek	(	tiger_renderer *	tr,
		kate_float	target
	)

Registers that a seek occured

Parameters

tr	the Tiger renderer on which the seek occured
target	the target time of the seek

Returns

0 success

TIGER_E_* error

References TIGER_E_INVALID_PARAMETER.

int tiger_renderer_set_buffer	(	tiger_renderer *	tr,
		unsigned char *	ptr,
		int	width,
		int	height,
		int	stride,
		int	swap_rgb
	)

Sets a buffer where to render the Kate stream. This buffer should be a linear buffer with 32 bits per pixel, with 8 bits per color component in ARGB order (or ABGR is swap_rgb is non zero) in host endianness. This buffer will be used as backing store for a Cairo surface, so any other requirement by Cairo also applies here.

Parameters

tr	the Tiger renderer for which to set the buffer
ptr	the data to use as backing store for the Cairo surface
width	the width of the Cairo surface to create
height	the height of the Cairo surface to create
stride	the stride of the Cairo surface to create
swap_rgb	if non zero, red and blue components are swapped

Returns

0 success

TIGER_E_* error

References TIGER_E_CAIRO_ERROR, and TIGER_E_INVALID_PARAMETER.

int tiger_renderer_set_default_background_fill_color	(	tiger_renderer *	tr,
		double	r,
		double	g,
		double	b,
		double	a
	)

Sets the default font color to use for background. The default is to not fill the background (though a Kate event may specify a background), but in cases where the text may be hard to read over a video, specifying a background fill color will allow the text to stand out more.

Parameters

tr	the Tiger renderer for which to set the background fill color
r	the red component of the background fill color, in the 0-1 range
g	the green component of the background fill color, in the 0-1 range
b	the blue component of the background fill color, in the 0-1 range
a	the alpha component of the background fill color, in the 0-1 range

Returns

0 success

TIGER_E_* error

References TIGER_E_INVALID_PARAMETER.

int tiger_renderer_set_default_font	(	tiger_renderer *	tr,
		const char *	font
	)

Sets the default font to use if none is specified

Parameters

tr	the Tiger renderer for which to set the default font
font	the font to use as default, a copy of which is made

Returns

0 success

TIGER_E_* error

References TIGER_E_INVALID_PARAMETER, and TIGER_E_OUT_OF_MEMORY.

int tiger_renderer_set_default_font_color	(	tiger_renderer *	tr,
		double	r,
		double	g,
		double	b,
		double	a
	)

Sets the default font color to use if none is specified

Parameters

tr	the Tiger renderer for which to set the default font color
r	the red component of the default color, in the 0-1 range
g	the green component of the default color, in the 0-1 range
b	the blue component of the default color, in the 0-1 range
a	the alpha component of the default color, in the 0-1 range

Returns

0 success

TIGER_E_* error

References TIGER_E_INVALID_PARAMETER.

int tiger_renderer_set_default_font_description	(	tiger_renderer *	tr,
		const char *	desc
	)

Sets the default font description to use if no override is specified

Parameters

tr	the Tiger renderer for which to set the default font
desc	the font description to use as default

Returns

0 success

TIGER_E_* error

References TIGER_E_INVALID_PARAMETER, and TIGER_E_OUT_OF_MEMORY.

int tiger_renderer_set_default_font_effect	(	tiger_renderer *	tr,
		tiger_font_effect	effect,
		double	strength
	)

Sets the default font effect. The default is to have no effect (tiger_font_plain).

Parameters

tr	the Tiger renderer for which to set which font effect to use
effect	the font effect to use
strength	how pronounced to make the effect (effect dependent)

Returns

0 success

TIGER_E_* error

References TIGER_E_INVALID_PARAMETER.

int tiger_renderer_set_default_font_size	(	tiger_renderer *	tr,
		double	size
	)

Sets the default font size to use if none is specified

Parameters

tr	the Tiger renderer for which to set the default font size
size	the font size to use as default

Returns

0 success

TIGER_E_* error

References TIGER_E_INVALID_PARAMETER, and TIGER_E_OUT_OF_MEMORY.

int tiger_renderer_set_quality	(	tiger_renderer *	tr,
		double	quality
	)

Sets a relative quality for the rendering

Parameters

tr	the Tiger renderer for which to set the quality
quality	rendering quality, between 0 (lowest, fastest) and 1 (highest, slowest), or negative for default quality

Returns

0 success

TIGER_E_* error

References TIGER_E_INVALID_PARAMETER.

int tiger_renderer_set_surface_clear_color	(	tiger_renderer *	tr,
		int	clear,
		double	r,
		double	g,
		double	b,
		double	a
	)

Sets whether to clear the surface before rendering, and the clearing color

Parameters

tr	the Tiger renderer to modify
clear	whether to clear before rendering
r	the red value of the clear color
g	the green value of the clear color
b	the blue value of the clear color
a	the alpha value of the clear color

Returns

0 success

TIGER_E_* error

References TIGER_E_INVALID_PARAMETER.

int tiger_renderer_update	(	tiger_renderer *	tr,
		kate_float	t,
		int	track
	)

Updates the renderer at the new time

Parameters

tr	the Tiger renderer to update
t	the time to update to renderer to
track	whether to update item trackers

Returns

0 success

1 success, but no Kate events are currently active

TIGER_E_* error

Note

Even if 0 is returned, a call to draw may not actually change the rendering surface, for instance if all active Kate events have a text with fully transparent color and no background, etc.

References TIGER_E_INVALID_PARAMETER.