Mercurial > games > semicongine
diff semiconginev2/old/resources/font.nim @ 1218:56781cc0fc7c compiletime-tests
did: renamge main package
author | sam <sam@basx.dev> |
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date | Wed, 17 Jul 2024 21:01:37 +0700 |
parents | semicongine/old/resources/font.nim@a3eb305bcac2 |
children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/semiconginev2/old/resources/font.nim Wed Jul 17 21:01:37 2024 +0700 @@ -0,0 +1,130 @@ +import std/tables +import std/strutils +import std/strformat +import std/streams +import std/os +import std/unicode +import std/logging + +import ../core/vector +import ../core/imagetypes +import ../core/fonttypes +import ../algorithms + +{.emit: "#define STBTT_STATIC".} +{.emit: "#define STB_TRUETYPE_IMPLEMENTATION".} +{.emit: "#include \"" & currentSourcePath.parentDir() & "/stb_truetype.h\"".} + +type stbtt_fontinfo {.importc, incompleteStruct.} = object + +proc stbtt_InitFont(info: ptr stbtt_fontinfo, data: ptr char, offset: cint): cint {.importc, nodecl.} +proc stbtt_ScaleForPixelHeight(info: ptr stbtt_fontinfo, pixels: cfloat): cfloat {.importc, nodecl.} + +proc stbtt_GetCodepointBitmap(info: ptr stbtt_fontinfo, scale_x: cfloat, scale_y: cfloat, codepoint: cint, width, height, xoff, yoff: ptr cint): cstring {.importc, nodecl.} +# proc stbtt_GetCodepointBitmapBox(info: ptr stbtt_fontinfo, codepoint: cint, scale_x, scale_y: cfloat, ix0, iy0, ix1, iy1: ptr cint) {.importc, nodecl.} + +proc stbtt_GetCodepointHMetrics(info: ptr stbtt_fontinfo, codepoint: cint, advance, leftBearing: ptr cint) {.importc, nodecl.} +proc stbtt_GetCodepointKernAdvance(info: ptr stbtt_fontinfo, ch1, ch2: cint): cint {.importc, nodecl.} +proc stbtt_FindGlyphIndex(info: ptr stbtt_fontinfo, codepoint: cint): cint {.importc, nodecl.} + +proc stbtt_GetFontVMetrics(info: ptr stbtt_fontinfo, ascent, descent, lineGap: ptr cint) {.importc, nodecl.} + +proc free(p: pointer) {.importc.} + +proc ReadTrueType*(stream: Stream, name: string, codePoints: seq[Rune], lineHeightPixels: float32): Font = + var + indata = stream.readAll() + fontinfo: stbtt_fontinfo + if stbtt_InitFont(addr fontinfo, addr indata[0], 0) == 0: + raise newException(Exception, "An error occured while loading PNG file") + + result.name = name + result.fontscale = float32(stbtt_ScaleForPixelHeight(addr fontinfo, cfloat(lineHeightPixels))) + + var ascent, descent, lineGap: cint + stbtt_GetFontVMetrics(addr fontinfo, addr ascent, addr descent, addr lineGap) + + result.lineHeight = float32(ascent - descent) * result.fontscale + result.lineAdvance = float32(ascent - descent + lineGap) * result.fontscale + + # ensure all codepoints are available in the font + for codePoint in codePoints: + if stbtt_FindGlyphIndex(addr fontinfo, cint(codePoint)) == 0: + warn &"Loading font {name}: Codepoint '{codePoint}' ({cint(codePoint)}) has no glyph" + + var + topOffsets: Table[Rune, int] + images: seq[Image[GrayPixel]] + let empty_image = NewImage[GrayPixel](1, 1, [0'u8]) + + for codePoint in codePoints: + var + width, height: cint + offX, offY: cint + let + data = stbtt_GetCodepointBitmap( + addr fontinfo, + result.fontscale, + result.fontscale, + cint(codePoint), + addr width, addr height, + addr offX, addr offY + ) + topOffsets[codePoint] = offY + + if char(codePoint) in UppercaseLetters: + result.capHeight = float32(height) + if codePoint == Rune('x'): + result.xHeight = float32(height) + + if width > 0 and height > 0: + var bitmap = newSeq[GrayPixel](width * height) + for i in 0 ..< width * height: + bitmap[i] = GrayPixel(data[i]) + images.add NewImage[GrayPixel](width.uint32, height.uint32, bitmap) + else: + images.add empty_image + + free(data) + + let packed = Pack(images) + + result.fontAtlas = Texture( + name: name & "_texture", + isGrayscale: true, + grayImage: packed.atlas, + sampler: FONTSAMPLER_SOFT, + ) + + let w = float32(packed.atlas.width) + let h = float32(packed.atlas.height) + for i in 0 ..< codePoints.len: + let + codePoint = codePoints[i] + image = images[i] + coord = (x: float32(packed.coords[i].x), y: float32(packed.coords[i].y)) + iw = float32(image.width) + ih = float32(image.height) + # horizontal spaces: + var advance, leftBearing: cint + stbtt_GetCodepointHMetrics(addr fontinfo, cint(codePoint), addr advance, addr leftBearing) + + result.glyphs[codePoint] = GlyphInfo( + dimension: NewVec2f(float32(image.width), float32(image.height)), + uvs: [ + NewVec2f((coord.x + 0.5) / w, (coord.y + ih - 0.5) / h), + NewVec2f((coord.x + 0.5) / w, (coord.y + 0.5) / h), + NewVec2f((coord.x + iw - 0.5) / w, (coord.y + 0.5) / h), + NewVec2f((coord.x + iw - 0.5) / w, (coord.y + ih - 0.5) / h), + ], + topOffset: float32(topOffsets[codePoint]), + leftOffset: float32(leftBearing) * result.fontscale, + advance: float32(advance) * result.fontscale, + ) + + for codePointAfter in codePoints: + result.kerning[(codePoint, codePointAfter)] = float32(stbtt_GetCodepointKernAdvance( + addr fontinfo, + cint(codePoint), + cint(codePointAfter) + )) * result.fontscale