cairo-dock-opengl-font.h File Reference

Data Structures
struct	_CairoDockGLFont
	Structure used to load a font for OpenGL text rendering. More...

Functions
GLuint	cairo_dock_create_texture_from_text_simple (const gchar *cText, const gchar *cFontDescription, cairo_t *pSourceContext, int *iWidth, int *iHeight)
CairoDockGLFont *	cairo_dock_load_textured_font (const gchar *cFontDescription, int first, int count)
CairoDockGLFont *	cairo_dock_load_textured_font_from_image (const gchar *cImagePath)
void	cairo_dock_free_gl_font (CairoDockGLFont *pFont)
void	cairo_dock_get_gl_text_extent (const gchar *cText, CairoDockGLFont *pFont, int *iWidth, int *iHeight)
void	cairo_dock_draw_gl_text (const guchar *cText, CairoDockGLFont *pFont)
void	cairo_dock_draw_gl_text_at_position (const guchar *cText, CairoDockGLFont *pFont, int x, int y)
void	cairo_dock_draw_gl_text_in_area (const guchar *cText, CairoDockGLFont *pFont, int iWidth, int iHeight, gboolean bCentered)
void	cairo_dock_draw_gl_text_at_position_in_area (const guchar *cText, CairoDockGLFont *pFont, int x, int y, int iWidth, int iHeight, gboolean bCentered)

Detailed Description

This class provides different ways to draw text directly in OpenGL. cairo_dock_create_texture_from_text_simple lets you draw any text in any font, by creating a texture from a Pango font description. This is a convenient function but not very fast. For a more efficient way, you load a font into a CairoDockGLFont with either : cairo_dock_load_textured_font to load a subset of a Mono font into textures. You then use cairo_dock_draw_gl_text_at_position to draw the text.

Function Documentation

GLuint cairo_dock_create_texture_from_text_simple	(	const gchar *	cText,
		const gchar *	cFontDescription,
		cairo_t *	pSourceContext,
		int *	iWidth,
		int *	iHeight
	)

Create a texture from a text. The text is drawn in white, so that you can later colorize it with a mere glColor.

Parameters

cText	the text
cFontDescription	a description of the font, for instance "Monospace Bold 12"
pSourceContext	a cairo context, not altered by the function.
iWidth	a pointer that will be filled with the width of the texture.
iHeight	a pointer that will be filled with the height of the texture.

Returns

a newly allocated texture.

CairoDockGLFont* cairo_dock_load_textured_font	(	const gchar *	cFontDescription,
		int	first,
		int	count
	)

Load a font into textures. You can then render your text like a normal texture (zoom, etc). The drawback is that only a mono font can be used with this function.

Parameters

cFontDescription	a description of the font, for instance "Monospace Bold 12"
first	first character to load.
count	number of characters to load.

Returns

a newly allocated opengl font.

CairoDockGLFont* cairo_dock_load_textured_font_from_image

(

const gchar *

cImagePath

)

Like the previous function, but loads the characters from an image. The image must be squared and contain the 256 extended ASCII characters in the alphabetic order.

Parameters

cImagePath

path to the image.

Returns

a newly allocated opengl font.

void cairo_dock_free_gl_font

(

CairoDockGLFont *

pFont

)

Free an opengl font.

Parameters

pFont

the font.

void cairo_dock_get_gl_text_extent	(	const gchar *	cText,
		CairoDockGLFont *	pFont,
		int *	iWidth,
		int *	iHeight
	)

Compute the size a text will take for a given font.

Parameters

cText	the text
pFont	the font.
iWidth	a pointer that will be filled with the width of the text.
iHeight	a pointer that will be filled with the height of the text.

void cairo_dock_draw_gl_text	(	const guchar *	cText,
		CairoDockGLFont *	pFont
	)

Render a text for a given font. In the case of a bitmap font, the current raster position is used. In the case of a texture font, the current model view is used.

Parameters

cText	the text
pFont	the font.

void cairo_dock_draw_gl_text_at_position	(	const guchar *	cText,
		CairoDockGLFont *	pFont,
		int	x,
		int	y
	)

Like /ref cairo_dock_draw_gl_text but at a given position.

Parameters

cText	the text
pFont	the font.
x	x position of the left bottom corner of the text.
y	y position of the left bottom corner of the text.

void cairo_dock_draw_gl_text_in_area	(	const guchar *	cText,
		CairoDockGLFont *	pFont,
		int	iWidth,
		int	iHeight,
		gboolean	bCentered
	)

Like /ref cairo_dock_draw_gl_text but resize the text so that it fits into a given area. Only works for a texture font.

Parameters

cText	the text
pFont	the font.
iWidth	iWidth of the area.
iHeight	iHeight of the area
bCentered	whether the text is centered on the current position or not.

void cairo_dock_draw_gl_text_at_position_in_area	(	const guchar *	cText,
		CairoDockGLFont *	pFont,
		int	x,
		int	y,
		int	iWidth,
		int	iHeight,
		gboolean	bCentered
	)

Like /ref cairo_dock_draw_gl_text_in_area and /ref cairo_dock_draw_gl_text_at_position.

Parameters

cText	the text
pFont	the font.
x	x position of the left bottom corner of the text.
y	y position of the left bottom corner of the text.
iWidth	iWidth of the area.
iHeight	iHeight of the area
bCentered	whether the text is centered on the given position or not.