func drawString(src image.Image, fontContext *freetype.Context, position raster.Point, text string) {
fontContext.SetSrc(src)
_, err := fontContext.DrawString(text, position)
if err != nil {
log.Println(err)
}
}
func drawFitCentered(c *freetype.Context, text string, img image.Image, bottom bool) {
lines, longest := splitLines(text)
// Calculate the font size that fits the longest line within the image width.
// Simplistic approach -- calculate the width of the line at MaxFontSize, then divide it
// down to get the appropriate font size. Not quite right, but close enough.
size := MaxFontSize
c.SetFontSize(MaxFontSize)
fw, _, _ := c.MeasureString(lines[longest])
w := int(fw >> 8)
ratio := float64(img.Bounds().Dx()-16) / float64(w)
size *= ratio
if size > MaxFontSize {
size = MaxFontSize
} else {
w = int(float64(w) * ratio)
}
c.SetFontSize(size)
pos := 0
for _, line := range lines {
fw, _, _ = c.MeasureString(line)
w := int(fw >> 8)
lineHeight := int(size * 1.2)
x := img.Bounds().Dx()/2 - w/2
y := 0
if bottom {
y = img.Bounds().Max.Y - 8 - (len(lines)-1)*lineHeight + pos
} else {
y = int(size) + 8 + pos
}
pos += lineHeight
drawBorderedText(c, line, x, y)
}
}
func drawBorderedText(c *freetype.Context, text string, x, y int) {
// God-awful hack to add a 2px black border around the text.
c.SetSrc(image.Black)
c.DrawString(text, freetype.Pt(x-2, y-2))
c.DrawString(text, freetype.Pt(x, y-2))
c.DrawString(text, freetype.Pt(x+2, y-2))
c.DrawString(text, freetype.Pt(x-2, y))
c.DrawString(text, freetype.Pt(x+2, y))
c.DrawString(text, freetype.Pt(x-2, y+2))
c.DrawString(text, freetype.Pt(x, y+2))
c.DrawString(text, freetype.Pt(x+2, y+2))
c.SetSrc(image.White)
c.DrawString(text, freetype.Pt(x, y))
}
func renderString(s string, c *freetype.Context) (*image.RGBA, int) {
estWidth := 8 * len(s)
dst := image.NewRGBA(image.Rect(0, 0, estWidth, h))
c.SetDst(dst)
c.SetClip(dst.Bounds())
c.SetSrc(&image.Uniform{C: shadow})
pt := freetype.Pt(0, 13)
c.DrawString(s, pt)
c.SetSrc(image.White)
pt = freetype.Pt(0, 12)
pt, _ = c.DrawString(s, pt)
return dst, getTextOffset(pt)
}
func drawText(font *truetype.Font, c *freetype.Context, color color.Color, rgba *image.RGBA, text string) (int, int) {
fg := image.NewUniform(color)
bg := image.Transparent
draw.Draw(rgba, rgba.Bounds(), bg, image.ZP, draw.Src)
c.SetFont(font)
c.SetDst(rgba)
c.SetSrc(fg)
c.SetClip(rgba.Bounds())
// height is the fraction of the font that is above the line, 1.0 would mean
// that the font never falls below the line
// TODO: wtf - this is all wrong!
// fix fonts - we can't change the font size easily
height := 1.3
pt := freetype.Pt(0, int(float64(c.PointToFix32(*size)>>8)*height))
adv, _ := c.DrawString(text, pt)
pt.X += adv.X
py := int(float64(pt.Y>>8)/height + 0.01)
return int(pt.X >> 8), py
}
func NextLine(c *freetype.Context, pt raster.Point) raster.Point {
return raster.Point{inset, pt.Y - c.PointToFix32(size*1.5)}
}