DynamicTextFont

class DynamicTextFont

Bases: TextFont, FreetypeFont

A DynamicTextFont is a special TextFont object that rasterizes its glyphs from a standard font file (e.g. a TTF file) on the fly. It requires the FreeType 2.0 library (or any higher, backward-compatible version).

Inheritance diagram

DynamicTextFont(Filename const &font_filename, int face_index = 0)

DynamicTextFont(char const *font_data, int data_length, int face_index)

DynamicTextFont(DynamicTextFont const &copy)

The constructor expects the name of some font file that FreeType can read, along with face_index, indicating which font within the file to load (usually 0).

This constructor accepts a table of data representing the font file, loaded from some source other than a filename on disk.

void clear(void)

Drops all the glyphs out of the cache and frees any association with any previously-generated pages.

Calling this frequently can result in wasted texture memory, as any previously rendered text will still keep a pointer to the old, previously- generated pages. As long as the previously rendered text remains around, the old pages will also remain around.

int garbage_collect(void)

Removes all of the glyphs from the font that are no longer being used by any Geoms. Returns the number of glyphs removed.

int get_anisotropic_degree(void) const

Returns the current anisotropic degree for textures created for this font. See set_anisotropic_degree().

LColor const &get_bg(void) const

Returns the color of the background pixels of the font as they are rendered into the font texture. See set_bg().

static TypeHandle get_class_type(void)

LColor const &get_fg(void) const

Returns the color of the foreground pixels of the font as they are rendered into the font texture. See set_fg().

int get_font_pixel_size(void) const

This is used to report whether the requested pixel size is being only approximated by a fixed-pixel-size font. This returns 0 in the normal case, in which a scalable font is used, or the fixed-pixel-size font has exactly the requested pixel size.

If this returns non-zero, it is the pixel size of the font that we are using to approximate our desired size.

PN_stdfloat get_line_height(void) const

Returns the number of units high each line of text is.

SamplerState::FilterType get_magfilter(void) const

Returns the filter type used when enlarging the textures created for this font.

SamplerState::FilterType get_minfilter(void) const

Returns the filter type used when minimizing the textures created for this font.

std::string const &get_name(void) const

Disambiguates the get_name() method between that inherited from TextFont and that inherited from FreetypeFont.

bool get_native_antialias(void) const

Returns whether Freetype’s built-in antialias mode is enabled. See set_native_antialias().

int get_num_pages(void) const

Returns the number of pages associated with the font. Initially, the font has zero pages; when the first piece of text is rendered with the font, it will add additional pages as needed. Each page is a Texture object that contains the images for each of the glyphs currently in use somewhere.

LColor const &get_outline_color(void) const

Returns the color of the outline pixels of the font as they are rendered into the font texture. See set_outline().

PN_stdfloat get_outline_feather(void) const

Returns the softness of the outline pixels of the font, as a value in the range 0.0 to 1.0. See set_outline().

PN_stdfloat get_outline_width(void) const

Returns the width of the outline pixels of the font, as the number of points beyond each letter. See set_outline().

DynamicTextPage *get_page(int n) const

Returns the nth page associated with the font. Initially, the font has zero pages; when the first piece of text is rendered with the font, it will add additional pages as needed. Each page is a Texture object that contains the images for each of the glyphs currently in use somewhere.

LVecBase2i const &get_page_size(void) const

Returns the size of the textures that are created for the DynamicTextFont. See set_page_size().

int get_page_x_size(void) const

Returns the x size of the textures that are created for the DynamicTextFont. See set_page_size().

int get_page_y_size(void) const

Returns the y size of the textures that are created for the DynamicTextFont. See set_page_size().

PN_stdfloat get_pixels_per_unit(void) const

Returns the resolution of the texture map. See set_pixels_per_unit().

PN_stdfloat get_point_size(void) const

Returns the point size of the font.

PN_stdfloat get_poly_margin(void) const

Returns the number of pixels of padding that is included around each glyph in the generated polygons. See set_poly_margin().

TextFont::RenderMode get_render_mode(void) const

Returns the way the glyphs on this particular font are generated. See set_render_mode().

PN_stdfloat get_scale_factor(void) const

Returns the antialiasing scale factor. See set_scale_factor().

PN_stdfloat get_space_advance(void) const

Returns the number of units wide a space is.

Texture::Format get_tex_format(void) const

Returns the texture format used to render the individual pages. This is set automatically according to the colors selected.

int get_texture_margin(void) const

Returns the number of pixels of padding that is added around the border of each glyph in the texture map. See set_texture_margin().

virtual PointerTo<TextFont> make_copy(void) const

Returns a new copy of the same font.

void set_anisotropic_degree(int anisotropic_degree)

Enables or disables anisotropic filtering on the textures created for this font. The default value is specified by the text-anisotropic-degree variable. See Texture::set_anisotropic_degree().

void set_bg(LColor const &bg)

Changes the color of the background pixels of the font as they are rendered into the font texture. The default is (1, 1, 1, 0), or transparent white, which allows text created with the font to be colored individually. (Note that it should not generally be (0, 0, 0, 0), which would tend to bleed into the foreground color, unless you have also specified a outline color of (0, 0, 0, 1)) .

Normally, you would not change this unless you really need a particular color effect to appear in the font itself.

This should only be called before any characters have been requested out of the font, or immediately after calling clear().

void set_fg(LColor const &fg)

Changes the color of the foreground pixels of the font as they are rendered into the font texture. The default is (1, 1, 1, 1), or opaque white, which allows text created with the font to be colored individually. Normally, you would not change this unless you really need a particular color effect to appear in the font itself.

This should only be called before any characters have been requested out of the font, or immediately after calling clear().

void set_magfilter(SamplerState::FilterType filter)

Sets the filter type used when enlarging the textures created for this font.

void set_minfilter(SamplerState::FilterType filter)

Sets the filter type used when minimizing the textures created for this font.

void set_native_antialias(bool native_antialias)

Sets whether the Freetype library’s built-in antialias mode is enabled. There are two unrelated ways to achieve antialiasing: with Freetype’s native antialias mode, and with the use of a scale_factor greater than one. By default, both modes are enabled.

At low resolutions, some fonts may do better with one mode or the other. In general, Freetype’s native antialiasing will produce less blurry results, but may introduce more artifacts.

void set_outline(LColor const &outline_color, PN_stdfloat outline_width, PN_stdfloat outline_feather)

Sets up the font to have an outline around each font letter. This is achieved via a Gaussian post-process as each letter is generated; there is some runtime cost for this effect, but it is minimal as each letter is normally generated only once and then cached.

The color is the desired color of the outline, width is the number of points beyond the letter that the outline extends (a typical font is 10 points high), and feather is a number in the range 0.0 .. 1.0 that controls the softness of the outline. Set the width to 0.0 to disable the outline.

This should only be called before any characters have been requested out of the font, or immediately after calling clear().

void set_page_size(LVecBase2i const &page_size)

void set_page_size(int x_size, int y_size)

Sets the x, y size of the textures that are created for the DynamicTextFont.

bool set_pixels_per_unit(PN_stdfloat pixels_per_unit)

Set the resolution of the texture map, and hence the clarity of the resulting font. This sets the number of pixels in the texture map that are used for each onscreen unit.

Setting this number larger results in an easier to read font, but at the cost of more texture memory.

This should only be called before any characters have been requested out of the font, or immediately after calling clear().

bool set_point_size(PN_stdfloat point_size)

Sets the point size of the font. This controls the apparent size of the font onscreen. By convention, a 10 point font is about 1 screen unit high.

This should only be called before any characters have been requested out of the font, or immediately after calling clear().

void set_poly_margin(PN_stdfloat poly_margin)

Sets the number of pixels of padding that is included around each glyph in the generated polygons. This helps prevent the edges of the glyphs from being cut off at small minifications. It is not related to the amount of extra pixels reserved in the texture map (but it should be set somewhat smaller than this number, which is controlled by set_texture_margin(), to prevent bleed-in from neighboring letters in the texture).

void set_render_mode(TextFont::RenderMode render_mode)

Specifies the way the glyphs on this particular font are generated. The default is RM_texture, which is the only mode supported for bitmap fonts. Other modes are possible for most modern fonts.

bool set_scale_factor(PN_stdfloat scale_factor)

Sets the factor by which the font is rendered larger by the FreeType library before being filtered down to its actual size in the texture as specified by set_pixels_per_unit(). This may be set to a number larger than 1.0 to improve the font’s antialiasing (since FreeType doesn’t really do a swell job of antialiasing by itself). There is some performance implication for setting this different than 1.0, but it is probably small.

This should only be called before any characters have been requested out of the font, or immediately after calling clear().

void set_texture_margin(int texture_margin)

Sets the number of pixels of padding that is added around the border of each glyph before adding it to the texture map. This reduces the bleed in from neighboring glyphs in the texture map.

virtual void write(std::ostream &out, int indent_level) const