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Added kerning for rendering text

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HW
2011-12-01 16:11:43 +01:00
parent 04772ea3ee
commit a02ae3a460
4 changed files with 151 additions and 9 deletions
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20
rendertext.lua
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@@ -23,10 +23,8 @@ end
function getglyph(face, facehash, charcode)
local hash = glyphcachehash(facehash, charcode)
if glyphcache[hash] == nil then
print("render glyph")
local glyph = face:renderGlyph(charcode)
local size = glyph.bb:getWidth() * glyph.bb:getHeight() / 2 + 32
print("cache claim")
glyphcacheclaim(size);
glyphcache[hash] = {
age = glyphcache_max_age,
@@ -45,13 +43,23 @@ function clearglyphcache()
glyphcache = {}
end
function renderUtf8Text(x, y, face, facehash, text)
function renderUtf8Text(x, y, face, facehash, text, kerning)
-- may still need more adaptive pen placement when kerning,
-- see: http://freetype.org/freetype2/docs/glyphs/glyphs-4.html
local pen_x = 0
local prevcharcode = 0
for uchar in string.gfind(text, "([%z\1-\127\194-\244][\128-\191]*)") do
local glyph = getglyph(face, facehash, util.utf8charcode(uchar))
fb:blitFrom(glyph.bb, x + pen_x + glyph.l, y - glyph.t, 0, 0, glyph.bb:getWidth(), glyph.bb:getHeight())
print(uchar, x + pen_x + glyph.l, y - glyph.t, glyph.bb:getWidth(), glyph.bb:getHeight())
local charcode = util.utf8charcode(uchar)
local glyph = getglyph(face, facehash, charcode)
if kerning and prevcharcode then
local kern = face:getKerning(prevcharcode, charcode)
pen_x = pen_x + kern
fb:addblitFrom(glyph.bb, x + pen_x + glyph.l, y - glyph.t, 0, 0, glyph.bb:getWidth(), glyph.bb:getHeight())
else
fb:blitFrom(glyph.bb, x + pen_x + glyph.l, y - glyph.t, 0, 0, glyph.bb:getWidth(), glyph.bb:getHeight())
end
pen_x = pen_x + glyph.ax
prevcharcode = charcode
end
end