Documentation
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Index ¶
- Constants
- func FindGlyphIndex(info *FontInfo, unicode_codepoint int) int
- func GetFontOffsetForIndex(data []byte, index int) int
- func GetFontVMetrics(info *FontInfo, ascent, descent, lineGap *int)
- func GetGlyphBitmapBoxSubpixel(font *FontInfo, glyph int, scale_x, scale_y, shift_x, shift_y float, ...)
- func GetPackedQuad(chardata []PackedChar, pw, ph, char_index int, xpos, ypos *float, ...)
- func InitFont(info *FontInfo, data []byte, offset int) int
- func PackBegin(spc *PackContext, pixels []byte, width, height, stride_in_bytes, padding int, ...) int
- func PackFontRangesRenderIntoRects(spc *PackContext, info *FontInfo, ranges []PackRange, num_ranges int, ...) int
- func PackSetOversampling(spc *PackContext, h_oversample, v_oversample uint)
- func STBTT_GPOS_TODO_assert(x bool)
- func STBTT_POINT_SIZE(x int) int
- func STBTT__COMPARE(a, b *stbtt__edge) int
- func STBTT_acos(x float32) float32
- func STBTT_assert(x bool)
- func STBTT_cos(x float32) float32
- func STBTT_fabs(x float32) float32
- func STBTT_fmod(x, y float32) float32
- func STBTT_iceil(x float32) int
- func STBTT_ifloor(x float32) int
- func STBTT_max(a, b int) int
- func STBTT_maxf(a, b float) float
- func STBTT_min(a, b int) int
- func STBTT_minf(a, b float) float
- func STBTT_pow(x, y float32) float32
- func STBTT_sqrt(x float32) float32
- func STBTT_strlen(str string) int
- func ScaleForMappingEmToPixels(info *FontInfo, pixels float) float
- func ScaleForPixelHeight(info *FontInfo, pixels float) float
- type AlignedQuad
- type FontInfo
- type PackContext
- type PackRange
- type PackedChar
Constants ¶
const ( STBTT_vmove = iota + 1 STBTT_vline STBTT_vcurve STBTT_vcubic )
const ( STBTT_MACSTYLE_DONTCARE = 0 STBTT_MACSTYLE_BOLD = 1 STBTT_MACSTYLE_ITALIC = 2 STBTT_MACSTYLE_UNDERSCORE = 4 STBTT_MACSTYLE_NONE = 8 // <= not same as 0, this makes us check the bitfield is 0 )
const ( STBTT_PLATFORM_ID_UNICODE = 0 STBTT_PLATFORM_ID_MAC = 1 STBTT_PLATFORM_ID_ISO = 2 STBTT_PLATFORM_ID_MICROSOFT = 3 )
const ( STBTT_UNICODE_EID_UNICODE_1_0 = 0 STBTT_UNICODE_EID_UNICODE_1_1 = 1 STBTT_UNICODE_EID_ISO_10646 = 2 STBTT_UNICODE_EID_UNICODE_2_0_BMP = 3 STBTT_UNICODE_EID_UNICODE_2_0_FULL = 4 )
const ( STBTT_MS_EID_SYMBOL = 0 STBTT_MS_EID_UNICODE_BMP = 1 STBTT_MS_EID_SHIFTJIS = 2 STBTT_MS_EID_UNICODE_FULL = 10 )
const ( STBTT_MAC_EID_ROMAN = 0 STBTT_MAC_EID_ARABIC = 4 STBTT_MAC_EID_JAPANESE = 1 STBTT_MAC_EID_HEBREW = 5 STBTT_MAC_EID_CHINESE_TRAD = 2 STBTT_MAC_EID_GREEK = 6 STBTT_MAC_EID_KOREAN = 3 STBTT_MAC_EID_RUSSIAN = 7 )
const ( // problematic because there are e.g. 16 english LCIDs and 16 arabic LCIDs STBTT_MS_LANG_ENGLISH = 0x0409 STBTT_MS_LANG_ITALIAN = 0x0410 STBTT_MS_LANG_CHINESE = 0x0804 STBTT_MS_LANG_JAPANESE = 0x0411 STBTT_MS_LANG_DUTCH = 0x0413 STBTT_MS_LANG_KOREAN = 0x0412 STBTT_MS_LANG_FRENCH = 0x040c STBTT_MS_LANG_RUSSIAN = 0x0419 STBTT_MS_LANG_GERMAN = 0x0407 STBTT_MS_LANG_SPANISH = 0x0409 STBTT_MS_LANG_HEBREW = 0x040d STBTT_MS_LANG_SWEDISH = 0x041D )
const ( STBTT_MAC_LANG_ENGLISH = 0 STBTT_MAC_LANG_JAPANESE = 11 STBTT_MAC_LANG_ARABIC = 12 STBTT_MAC_LANG_KOREAN = 23 STBTT_MAC_LANG_DUTCH = 4 STBTT_MAC_LANG_RUSSIAN = 32 STBTT_MAC_LANG_FRENCH = 1 STBTT_MAC_LANG_SPANISH = 6 STBTT_MAC_LANG_GERMAN = 2 STBTT_MAC_LANG_SWEDISH = 5 STBTT_MAC_LANG_HEBREW = 10 STBTT_MAC_LANG_CHINESE_SIMPLIFIED = 33 STBTT_MAC_LANG_ITALIAN = 3 STBTT_MAC_LANG_CHINESE_TRAD = 19 )
const STBTT_MAX_OVERSAMPLE = 8
const STBTT_RASTERIZER_VERSION = 2
const STBTT__OVER_MASK = STBTT_MAX_OVERSAMPLE - 1
Variables ¶
This section is empty.
Functions ¶
func FindGlyphIndex ¶
func FindGlyphIndex(info *FontInfo, unicode_codepoint int) int
If you're going to perform multiple operations on the same character and you want a speed-up, call this function with the character you're going to process, then use glyph-based functions instead of the codepoint-based functions. Returns 0 if the character codepoint is not defined in the font.
func GetFontOffsetForIndex ¶
func GetFontOffsetForIndex(data []byte, index int) int
Each .ttf/.ttc file may have more than one font. Each font has a sequential index number starting from 0. Call this function to get the font offset for a given index; it returns -1 if the index is out of range. A regular .ttf file will only define one font and it always be at offset 0, so it will return '0' for index 0, and -1 for all other indices.
func GetFontVMetrics ¶
func GetFontVMetrics(info *FontInfo, ascent, descent, lineGap *int)
ascent is the coordinate above the baseline the font extends; descent is the coordinate below the baseline the font extends (i.e. it is typically negative) lineGap is the spacing between one row's descent and the next row's ascent... so you should advance the vertical position by "*ascent - *descent + *lineGap"
these are expressed in unscaled coordinates, so you must multiply by the scale factor for a given size
func GetGlyphBitmapBoxSubpixel ¶
func GetGlyphBitmapBoxSubpixel(font *FontInfo, glyph int, scale_x, scale_y, shift_x, shift_y float, ix0, iy0, ix1, iy1 *int)
func GetPackedQuad ¶
func GetPackedQuad(chardata []PackedChar, pw, ph, char_index int, xpos, ypos *float, q *AlignedQuad, align_to_integer int)
func InitFont ¶
Given an offset into the file that defines a font, this function builds the necessary cached info for the rest of the system. You must allocate the stbtt_fontinfo yourself, and InitFont will fill it out. You don't need to do anything special to free it, because the contents are pure value data with no additional data structures. Returns 0 on failure.
func PackBegin ¶
func PackBegin(spc *PackContext, pixels []byte, width, height, stride_in_bytes, padding int, alloc_context any) int
Initializes a packing context stored in the passed-in stbtt_pack_context. Future calls using this context will pack characters into the bitmap passed in here: a 1-channel bitmap that is width * height. stride_in_bytes is the distance from one row to the next (or 0 to mean they are packed tightly together). "padding" is the amount of padding to leave between each character (normally you want '1' for bitmaps you'll use as textures with bilinear filtering).
Returns 0 on failure, 1 on success.
func PackFontRangesRenderIntoRects ¶
func PackFontRangesRenderIntoRects(spc *PackContext, info *FontInfo, ranges []PackRange, num_ranges int, rects []stbrp.Rect) int
func PackSetOversampling ¶
func PackSetOversampling(spc *PackContext, h_oversample, v_oversample uint)
Oversampling a font increases the quality by allowing higher-quality subpixel positioning, and is especially valuable at smaller text sizes.
This function sets the amount of oversampling for all following calls to stbtt_PackFontRange(s) or stbtt_PackFontRangesGatherRects for a given pack context. The default (no oversampling) is achieved by h_oversample=1 and v_oversample=1. The total number of pixels required is h_oversample*v_oversample larger than the default; for example, 2x2 oversampling requires 4x the storage of 1x1. For best results, render oversampled textures with bilinear filtering. Look at the readme in stb/tests/oversample for information about oversampled fonts
To use with PackFontRangesGather etc., you must set it before calls call to PackFontRangesGatherRects.
func STBTT_GPOS_TODO_assert ¶
func STBTT_GPOS_TODO_assert(x bool)
func STBTT_POINT_SIZE ¶
func STBTT_POINT_SIZE(x int) int
func STBTT__COMPARE ¶
func STBTT__COMPARE(a, b *stbtt__edge) int
func STBTT_acos ¶
func STBTT_assert ¶
func STBTT_assert(x bool)
func STBTT_fabs ¶
func STBTT_fmod ¶
func STBTT_iceil ¶
func STBTT_iceil(x float32) int
func STBTT_ifloor ¶
func STBTT_ifloor(x float32) int
func STBTT_maxf ¶
func STBTT_maxf(a, b float) float
func STBTT_minf ¶
func STBTT_minf(a, b float) float
func STBTT_sqrt ¶
func STBTT_strlen ¶
func STBTT_strlen(str string) int
func ScaleForMappingEmToPixels ¶
func ScaleForMappingEmToPixels(info *FontInfo, pixels float) float
computes a scale factor to produce a font whose EM size is mapped to 'pixels' tall. This is probably what traditional APIs compute, but I'm not positive.
func ScaleForPixelHeight ¶
func ScaleForPixelHeight(info *FontInfo, pixels float) float
computes a scale factor to produce a font whose "height" is 'pixels' tall. Height is measured as the distance from the highest ascender to the lowest descender; in other words, it's equivalent to calling stbtt_GetFontVMetrics and computing:
scale = pixels / (ascent - descent)
so if you prefer to measure height by the ascent only, use a similar calculation.
Types ¶
type AlignedQuad ¶
type AlignedQuad struct {
X0, Y0, S0, T0 float // top-left
X1, Y1, S1, T1 float // bottom-right
}
type FontInfo ¶
type FontInfo struct {
// contains filtered or unexported fields
}
The following structure is defined publicly so you can declare one on the stack or as a global or etc, but you should treat it as opaque.
type PackContext ¶
type PackContext struct {
PackInfo any
Height int
Pixels []byte
// contains filtered or unexported fields
}
this is an opaque structure that you shouldn't mess with which holds all the context needed from PackBegin to PackEnd.
type PackRange ¶
type PackRange struct {
FontSize float
FirstUnicodeCodepointInRange int // if non-zero, then the chars are continuous, and this is the first codepoint
ArrayOfUnicodeCodepoints []int // if non-zero, then this is an array of unicode codepoints
NumChars int
ChardataForRange []PackedChar // output
Oversample struct {
H, V byte
}
}
type PackedChar ¶
type PackedChar struct {
AdvanceX float
// contains filtered or unexported fields
}
Source Files