func main() {
// Example file used here is Lenna50.jpg from the task "Percentage
// difference between images" converted with with the command
// convert Lenna50.jpg -colorspace gray Lenna50.ppm
// It shows very obvious compression artifacts when viewed at higher
// zoom factors.
b, err := raster.ReadPpmFile("Lenna50.ppm")
if err != nil {
fmt.Println(err)
return
}
g0 = b.Grmap()
w, h := g0.Extent()
g1 = raster.NewGrmap(w, h)
for y := 0; y < h; y++ {
for x := 0; x < w; x++ {
g1.SetPx(x, y, median(x, y))
}
}
// side by side comparison with input file shows compression artifacts
// greatly smoothed over, although at some loss of contrast.
err = g1.Bitmap().WritePpmFile("median.ppm")
if err != nil {
fmt.Println(err)
}
}
func main() {
g = raster.NewGrmap(w, h)
// off center seed position makes pleasingly asymetrical tree
g.SetPx(w/3, h/3, frost)
var x, y int
generate:
for a := 0; a < n; {
// generate random position for new particle
x, y = rand.Intn(w), rand.Intn(h)
switch p, ok := g.GetPx(x, y); p {
case frost:
// position is already set. find a nearby free position.
for p == frost {
x += rand.Intn(3) - 1
y += rand.Intn(3) - 1
p, ok = g.GetPx(x, y)
// execpt if we run out of bounds, consider the particle lost.
if !ok {
continue generate
}
}
default:
// else particle is in free space. let it wander
// until it touches tree
for !hasNeighbor(x, y) {
x += rand.Intn(3) - 1
y += rand.Intn(3) - 1
// but again, if it wanders out of bounds consider it lost.
_, ok = g.GetPx(x, y)
if !ok {
continue generate
}
}
}
// x, y now specify a free position toucing the tree.
g.SetPx(x, y, frost)
a++
// progress indicator
if a%100 == 0 {
fmt.Println(a, "of", n)
}
}
g.Bitmap().WritePpmFile("tree.ppm")
}
func main() {
g := raster.NewGrmap(400, 300)
g.AaLine(7.4, 12.3, 307, 122.5)
g.AaLine(177.4, 12.3, 127, 222.5)
g.Bitmap().WritePpmFile("wu.ppm")
}
func main() {
g := raster.NewGrmap(width, height)
ftree(g, width/2, height*9/10, length, 0, depth)
g.Bitmap().WritePpmFile("ftree.ppm")
}