https://github.com/rsduck/stb_truetype-nim

A Nim wrapper for the stb_truetype library
https://github.com/rsduck/stb_truetype-nim

fonts nim opengl stb truetype wrapper

Last synced: 22 days ago
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A Nim wrapper for the stb_truetype library

• Host: GitHub
• URL: https://github.com/rsduck/stb_truetype-nim
• Owner: RSDuck
• License: other
• Created: 2017-09-25T17:09:47.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2017-09-25T17:10:12.000Z (over 7 years ago)
• Last Synced: 2024-11-19T08:44:35.175Z (3 months ago)
• Topics: fonts, nim, opengl, stb, truetype, wrapper
• Language: Nim
• Size: 51.8 KB
• Stars: 0
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Partial Nim stb_truetype wrapper

This is a partial wrapper of [stb_truetype](https://github.com/nothings/stb/blob/master/stb_truetype.h)(`v1.17`) for the Nim programming language. It exposes only the more advanced procedures for loading fonts to use them with 3D APIs (e.g. OpenGL or DirectX), but not the basic 3D API nor the font loading. [stb_rect_pack](https://github.com/nothings/stb/blob/master/stb_rect_pack.h)(`v0.11`) is also included, so stb_truetype will it's more efficient packing algorithm.

Both libraries are included in the wrapper, `nimble install` should be enough the use it.

## License

Due to stb_truetype and stb_rect_pack being dual licensed under Unlicense and MIT license, I put this wrapper under the same conditions. See `LICENSE` for details.

## Example

Depends on [stb_image](https://gitlab.com/define-private-public/stb_image-Nim) for writing to images

```nim

import stb_truetype, stb_image/write as stbw, sequtils, unicode

var 

    spc = PackContext()

    data = newString(256 * 256)

    fontData = readFile(r"c:\windows\fonts\arial.ttf") # Windows only, change it to the type face of your choice

    char_data = newSeq[PackedChar]()

discard packBegin(spc, data, 256, 256, 256, 1)

discard packFontRange(spc, fontData, 0, 16.0, 64, 256 + 128, char_data)

packSetOverampling(spc, 1, 1)

let ranges = packFontRanges(spc, fontData, 0, [

    PackRange(typ: packRangeRange, font_size: 12.0, first_unicode_char_in_range: 256, num_chars: 10),

    PackRange(typ: packRangeSeq, font_size: 22.0, array_of_unicode_codepoints: @[

        ord('$'), ord('^'), ord('{'), int runeAtPos("ß", 0), int runeAtPos("Ω", 0), int runeAtPos("я", 0)])])

packEnd(spc)

proc lerp(s, t, v: float32): float32 = s + (t - s) * v

#scrappy cut out function

var

    x = 0f

    y = 0f

let 

    rect = getPackedQuad(ranges[1][1][4], 256, 256, x, y, true)

    rw = int rect.x1 - rect.x0

    rh = int rect.y1 - rect.y0

var singleChar = newSeq[byte](rw * rh)

for j in 0..rh - 1:

    for i in 0..rw - 1:

        let

            x = int(lerp(rect.s0, rect.s1, float32(i) / float32(rw)) * 256)

            y = int(lerp(rect.t0, rect.t1, float32(j) / float32(rh)) * 256)

        singleChar[i + j * rw] = (byte data[x + y * 256])

writePNG("test2.png", rw, rh, 1, singleChar) # should contain only an Omega

writePng("test.png", 256, 256, 1, cast[seq[uint8]](toSeq(items data))) # should contain every rendered character

```