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use std::ptr::null_mut;
use {ffi, Bitmap, FtResult, Glyph, GlyphMetrics, Outline, RenderMode, Vector};
/// A description of a given subglyph returned by `GlyphSlot::get_subglyph_info`
/// function.
#[derive(Copy, Clone)]
pub struct SubGlyphInfo {
/// The glyph index of the subglyph.
pub index: i32,
/// The subglyph flags, see FT_SUBGLYPH_FLAG_XXX.
pub flags: u32,
/// The subglyph's first argument (if any).
pub arg1: i32,
/// The subglyph's second argument (if any).
pub arg2: i32,
/// The subglyph transformation (if any).
pub transform: ffi::FT_Matrix,
}
impl Default for SubGlyphInfo {
fn default() -> Self {
SubGlyphInfo {
index: 0,
flags: 0,
arg1: 0,
arg2: 0,
transform: ffi::FT_Matrix {
xx: 0,
xy: 0,
yx: 0,
yy: 0,
},
}
}
}
/// A struct encapsulating the space for a glyph within a `Library`
#[derive(Copy, Clone, Eq, PartialEq, Hash)]
pub struct GlyphSlot {
library_raw: ffi::FT_Library,
raw: ffi::FT_GlyphSlot,
}
impl GlyphSlot {
/// Create a `GlyphSlot` from its constituent C parts
pub unsafe fn from_raw(library_raw: ffi::FT_Library, raw: ffi::FT_GlyphSlot) -> Self {
GlyphSlot { library_raw, raw }
}
/// Convert a given glyph image to a bitmap. It does so by inspecting the glyph image format,
/// finding the relevant renderer, and invoking it.
pub fn render_glyph(&self, render_mode: RenderMode) -> FtResult<()> {
let err = unsafe { ffi::FT_Render_Glyph(self.raw, render_mode as u32) };
if err == ffi::FT_Err_Ok {
Ok(())
} else {
Err(err.into())
}
}
/// Retrieve a description of a given subglyph. Only use it if the glyph's format is
/// FT_GLYPH_FORMAT_COMPOSITE; an error is returned otherwise.
pub fn get_subglyph_info(&self, sub_index: u32) -> FtResult<SubGlyphInfo> {
let mut info = SubGlyphInfo::default();
let err = unsafe {
ffi::FT_Get_SubGlyph_Info(
self.raw,
sub_index,
&mut info.index,
&mut info.flags,
&mut info.arg1,
&mut info.arg2,
&mut info.transform,
)
};
if err == ffi::FT_Err_Ok {
Ok(info)
} else {
Err(err.into())
}
}
/// Returns a glyph object, that is similar to a `GlyphSlot` but managed outside of the library
pub fn get_glyph(&self) -> FtResult<Glyph> {
let mut aglyph = null_mut();
let err = unsafe { ffi::FT_Get_Glyph(self.raw, &mut aglyph) };
if err == ffi::FT_Err_Ok {
Ok(unsafe { Glyph::from_raw(self.library_raw, aglyph) })
} else {
Err(err.into())
}
}
/// In freetype, the `Outline` object is a scalable glyph. This method unpacks a glyph into
/// this object, or returns `None` if the glyph has no `outline`
pub fn outline(&self) -> Option<Outline> {
let outline = unsafe { &(*self.raw).outline };
let format = unsafe { (*self.raw).format };
if format == ffi::FT_GLYPH_FORMAT_OUTLINE {
let outline = unsafe { Outline::from_raw(outline) };
Some(outline)
} else {
None
}
}
/// This field is used as a bitmap descriptor when the slot format is FT_GLYPH_FORMAT_BITMAP.
/// Note that the address and content of the bitmap buffer can change between calls of
/// FT_Load_Glyph and a few other functions.
#[inline(always)]
pub fn bitmap(&self) -> Bitmap {
unsafe { Bitmap::from_raw(&(*self.raw).bitmap) }
}
/// The bitmap's left bearing expressed in integer pixels. Only valid if the format is
/// FT_GLYPH_FORMAT_BITMAP, this is, if the glyph slot contains a bitmap.
#[inline(always)]
pub fn bitmap_left(&self) -> i32 {
unsafe { (*self.raw).bitmap_left }
}
/// The bitmap's top bearing expressed in integer pixels. Remember that this is the distance
/// from the baseline to the top-most glyph scanline, upwards y coordinates being positive.
#[inline(always)]
pub fn bitmap_top(&self) -> i32 {
unsafe { (*self.raw).bitmap_top }
}
/// This shorthand is, depending on FT_LOAD_IGNORE_TRANSFORM, the transformed (hinted) advance
/// width for the glyph, in 26.6 fractional pixel format. As specified with
/// FT_LOAD_VERTICAL_LAYOUT, it uses either the ‘horiAdvance’ or the ‘vertAdvance’ value of
/// ‘metrics’ field.
#[inline(always)]
pub fn advance(&self) -> Vector {
unsafe { (*self.raw).advance }
}
/// The advance width of the unhinted glyph. Its value is expressed in 16.16 fractional pixels,
/// unless FT_LOAD_LINEAR_DESIGN is set when loading the glyph. This field can be important to
/// perform correct WYSIWYG layout. Only relevant for outline glyphs.
#[inline(always)]
pub fn linear_hori_advance(&self) -> ffi::FT_Fixed {
unsafe { (*self.raw).linearHoriAdvance }
}
/// The advance height of the unhinted glyph. Its value is expressed in 16.16 fractional
/// pixels, unless FT_LOAD_LINEAR_DESIGN is set when loading the glyph. This field can be
/// important to perform correct WYSIWYG layout. Only relevant for outline glyphs.
#[inline(always)]
pub fn linear_vert_advance(&self) -> ffi::FT_Fixed {
unsafe { (*self.raw).linearVertAdvance }
}
/// The metrics of the last loaded glyph in the slot. The returned values depend on the last
/// load flags (see the FT_Load_Glyph API function) and can be expressed either in 26.6
/// fractional pixels or font units.
#[inline(always)]
pub fn metrics(&self) -> GlyphMetrics {
unsafe { (*self.raw).metrics }
}
/// Get a pointer to the underlying c struct
#[inline(always)]
pub fn raw(&self) -> &ffi::FT_GlyphSlotRec {
unsafe { &*self.raw }
}
}