pub struct Atlas {
id: c_uint,
width: i32,
height: i32,
row_extent: i32,
row_baseline: i32,
row_tallest: i32,
is_gles_context: bool,
}
Expand description
Manages a single texture atlas.
The strategy for filling an atlas looks roughly like this:
(width, height)
┌─────┬─────┬─────┬─────┬─────┐
│ 10 │ │ │ │ │ <- Empty spaces; can be filled while
│ │ │ │ │ │ glyph_height < height - row_baseline
├─────┼─────┼─────┼─────┼─────┤
│ 5 │ 6 │ 7 │ 8 │ 9 │
│ │ │ │ │ │
├─────┼─────┼─────┼─────┴─────┤ <- Row height is tallest glyph in row; this is
│ 1 │ 2 │ 3 │ 4 │ used as the baseline for the following row.
│ │ │ │ │ <- Row considered full when next glyph doesn't
└─────┴─────┴─────┴───────────┘ fit in the row.
(0, 0) x->
Fields§
§id: c_uint
Texture id for this atlas.
width: i32
Width of atlas.
height: i32
Height of atlas.
row_extent: i32
Left-most free pixel in a row.
This is called the extent because it is the upper bound of used pixels in a row.
row_baseline: i32
Baseline for glyphs in the current row.
row_tallest: i32
Tallest glyph in current row.
This is used as the advance when end of row is reached.
is_gles_context: bool
Gles context.
This affects the texture loading.
Implementations§
source§impl Atlas
impl Atlas
pub fn new(size: i32, is_gles_context: bool) -> Self
pub fn clear(&mut self)
sourcepub fn insert(
&mut self,
glyph: &RasterizedGlyph,
active_tex: &mut u32
) -> Result<Glyph, AtlasInsertError>
pub fn insert( &mut self, glyph: &RasterizedGlyph, active_tex: &mut u32 ) -> Result<Glyph, AtlasInsertError>
Insert a RasterizedGlyph into the texture atlas.
sourcefn insert_inner(&mut self, glyph: &RasterizedGlyph, active_tex: &mut u32) -> Glyph
fn insert_inner(&mut self, glyph: &RasterizedGlyph, active_tex: &mut u32) -> Glyph
Insert the glyph without checking for room.
Internal function for use once atlas has been checked for space. GL errors could still occur at this point if we were checking for them; hence, the Result.
sourcepub fn room_in_row(&self, raw: &RasterizedGlyph) -> bool
pub fn room_in_row(&self, raw: &RasterizedGlyph) -> bool
Check if there’s room in the current row for given glyph.
sourcepub fn advance_row(&mut self) -> Result<(), AtlasInsertError>
pub fn advance_row(&mut self) -> Result<(), AtlasInsertError>
Mark current row as finished and prepare to insert into the next row.
sourcepub fn load_glyph(
active_tex: &mut c_uint,
atlas: &mut Vec<Atlas>,
current_atlas: &mut usize,
rasterized: &RasterizedGlyph
) -> Glyph
pub fn load_glyph( active_tex: &mut c_uint, atlas: &mut Vec<Atlas>, current_atlas: &mut usize, rasterized: &RasterizedGlyph ) -> Glyph
Load a glyph into a texture atlas.
If the current atlas is full, a new one will be created.