func renderPage(ctx *fz.Context, doc *fz.Document, pageIndex int, opt *RenderOption, buf []Pixel) {
page := doc.LoadPage(pageIndex)
defer doc.FreePage(page)
var bounds fz.Rect
doc.BoundPage(page, &bounds)
zoom := float32(opt.Width) / bounds.X1
var transform fz.Matrix
transform.Scale(zoom, zoom)
bounds.Transform(&transform)
var bbox fz.Irect
bbox.RoundRect(&bounds)
pix := ctx.NewPixmapWithBboxAndData(ctx.DeviceRgb(), &bbox,
(*byte)(unsafe.Pointer(&buf[0])))
ctx.ClearPixmapWithValue(pix, 0xFF)
dev := fz.NewDeviceHook(ctx.NewDrawDevice(pix))
defer dev.Free()
var imgRects Rects
dev.ImageHook = func(image *fz.Image, ctm *fz.Matrix, alpha float32) {
pt := fz.Point{0, 0}
pt.Transform(ctm)
x, y := int(pt.X), int(pt.Y)
w := round(sqrtf(ctm.A*ctm.A+ctm.B*ctm.B) + 1)
h := round(sqrtf(ctm.C*ctm.C+ctm.D*ctm.D) + 1)
imgRects = append(imgRects, &Rect{x, y, w, h})
}
doc.RunPage(page, dev.ToDevice(), &transform, nil)
if opt.Dark {
pixels := buf
off := 0
b := opt.Brightness
bb := b * b
for y := 0; y < int(pix.H); y++ {
for x := 0; x < int(pix.W); x++ {
pixel := pixels[off+x]
rgb := color.RGBFromBytes(pixel.GetRGB())
if !imgRects.In(x, y) {
hcl := rgb.ToHCL()
hcl.L = 1 - hcl.L
rgb = hcl.ToRGB()
rgb.Times(b)
} else {
rgb.Times(bb)
}
pixels[off+x].SetRGB(rgb.ToBytes())
}
off += int(pix.W)
}
}
}
func (m *Model) setWidth(width int) {
if width != m.Width {
m.Width = width
m.heights = make([]int, m.PageCount())
m.height = 0
for i := 0; i < m.PageCount(); i++ {
page := m.doc.LoadPage(i)
var bounds fz.Rect
m.doc.BoundPage(page, &bounds)
zoom := float32(width) / bounds.X1
var transform fz.Matrix
transform.Scale(zoom, zoom)
bounds.Transform(&transform)
var bbox fz.Irect
bbox.RoundRect(&bounds)
m.height += int(bbox.Y1)
m.heights[i] = int(bbox.Y1)
m.doc.FreePage(page)
}
m.cache = make([]Pixel, m.Width*m.height)
m.cached = make([]bool, m.PageCount())
}
}