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example/vector: Add the logo

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There is a known issue in the logo rendering.
This commit is contained in:
Hajime Hoshi 2019-12-28 16:22:18 +09:00
parent f1a788801c
commit 6edb586f52
3 changed files with 111 additions and 30 deletions
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29
examples/vector/main.go
View File

@ -98,6 +98,34 @@ func drawEbitenText(screen *ebiten.Image) {
path.Fill(screen, color.White)
}
func drawEbitenLogo(screen *ebiten.Image, x, y int) {
const unit = 16
var path vector.Path
xf, yf := float32(x), float32(y)
path.MoveTo(xf, yf+4*unit)
path.LineTo(xf, yf+6*unit)
path.LineTo(xf+2*unit, yf+6*unit)
path.LineTo(xf+2*unit, yf+5*unit)
path.LineTo(xf+3*unit, yf+5*unit)
path.LineTo(xf+3*unit, yf+4*unit)
path.LineTo(xf+4*unit, yf+4*unit)
path.LineTo(xf+4*unit, yf+2*unit)
path.LineTo(xf+6*unit, yf+2*unit)
path.LineTo(xf+6*unit, yf+1*unit)
path.LineTo(xf+5*unit, yf+1*unit)
path.LineTo(xf+5*unit, yf)
path.LineTo(xf+4*unit, yf)
path.LineTo(xf+4*unit, yf+2*unit)
path.LineTo(xf+2*unit, yf+2*unit)
path.LineTo(xf+2*unit, yf+3*unit)
path.LineTo(xf+unit, yf+3*unit)
path.LineTo(xf+unit, yf+4*unit)
path.Fill(screen, color.RGBA{0xdb, 0x56, 0x20, 0xff})
}
var counter = 0
func update(screen *ebiten.Image) error {
@ -107,6 +135,7 @@ func update(screen *ebiten.Image) error {
}
drawEbitenText(screen)
drawEbitenLogo(screen, 20, 80)
return nil
}

57
vector/internal/math/triangulate.go
View File

@ -45,34 +45,9 @@ func Triangulate(pts []Point) []uint16 {
var currentIndices []uint16
// Remove duplicated points
dup:
for i := range pts {
for j := 0; j < i; j++ {
if pts[i] == pts[j] {
continue dup
}
}
currentIndices = append(currentIndices, uint16(i))
}
if len(currentIndices) < 3 {
return nil
}
// Determine the direction of the polygon from the upper-left point.
var upperLeft int
for ci, i := range currentIndices {
if pts[upperLeft].X < pts[i].X {
upperLeft = int(ci)
}
if pts[upperLeft].X == pts[i].X && pts[upperLeft].Y < pts[i].Y {
upperLeft = int(ci)
}
}
i0, i1, i2 := adjacentIndices(currentIndices, upperLeft)
pt0 := pts[i0]
pt1 := pts[i1]
pt2 := pts[i2]
clockwise := triangleCross(pt0, pt1, pt2) < 0
var indices []uint16
@ -81,25 +56,43 @@ dup:
for len(currentIndices) >= 3 {
// Calculate cross-products and remove unneeded vertices.
cs := make([]float32, len(currentIndices))
idx := -1
idxToRemove := -1
// Determine the direction of the polygon from the upper-left point.
var upperLeft int
for i := range currentIndices {
next := (i + 1) % len(currentIndices)
if pts[currentIndices[i]] == pts[currentIndices[next]] {
idxToRemove = next
break
}
i0, i1, i2 := adjacentIndices(currentIndices, i)
pt0 := pts[i0]
pt1 := pts[i1]
pt2 := pts[i2]
c := triangleCross(pt0, pt1, pt2)
if c == 0 {
idx = i
idxToRemove = i
break
}
cs[i] = c
if pts[currentIndices[upperLeft]].X > pts[currentIndices[i]].X {
upperLeft = i
} else if pts[currentIndices[upperLeft]].X == pts[currentIndices[i]].X &&
pts[currentIndices[upperLeft]].Y > pts[currentIndices[i]].Y {
upperLeft = i
}
}
if idx != -1 {
currentIndices = append(currentIndices[:idx], currentIndices[idx+1:]...)
if idxToRemove != -1 {
currentIndices = append(currentIndices[:idxToRemove], currentIndices[idxToRemove+1:]...)
continue
}
idx = -1
clockwise := cs[upperLeft] < 0
idx := -1
index:
for i := range currentIndices {
i0, i1, i2 := adjacentIndices(currentIndices, i)
@ -119,6 +112,10 @@ dup:
if l := len(currentIndices); j == (i+l-1)%l || j == i || j == (i+1)%l {
continue
}
jj := currentIndices[j]
if pts[i0] == pts[jj] || pts[i1] == pts[jj] || pts[i2] == pts[jj] {
continue
}
if InTriangle(pts[currentIndices[j]], pt0, pt1, pt2) {
// If the triangle includes another point, the triangle is not an ear.
continue index

55
vector/internal/math/triangulate_test.go
View File

@ -215,6 +215,61 @@ func TestTriangulate(t *testing.T) {
},
Out: []uint16{8, 0, 1, 1, 2, 4, 1, 4, 5, 8, 1, 5, 8, 5, 7},
},
{
In: []Point{
{0, 0},
{0, 1},
{1, 1},
{1, 0},
{2, 0},
},
Out: []uint16{3, 0, 1, 3, 1, 2},
},
{
In: []Point{
{2, 0},
{0, 0},
{1, 0},
{1, 1},
{2, 1},
},
Out: []uint16{4, 0, 2, 4, 2, 3},
},
{
In: []Point{
{2, 0},
{2, 1},
{1, 1},
{1, 0},
{0, 0},
},
Out: []uint16{3, 0, 1, 3, 1, 2},
},
{
// Butterfly
In: []Point{
{0, 0},
{0, 2},
{1, 1},
{2, 2},
{2, 0},
{1, 1},
},
Out: []uint16{5, 0, 1, 5, 3, 4},
},
{
In: []Point{
{0, 6},
{0, 9},
{6, 6},
{6, 3},
{9, 3},
{8, 0},
{6, 0},
{6, 3},
},
Out: []uint16{7, 0, 1, 7, 1, 2, 7, 4, 5, 7, 5, 6},
},
}
for _, tc := range tests {
got := Triangulate(tc.In)