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non-working aabb/line sweep
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package main | |
import ( | |
"image/color" | |
"log" | |
"math" | |
"sort" | |
"github.com/hajimehoshi/ebiten/v2" | |
"github.com/hajimehoshi/ebiten/v2/ebitenutil" | |
) | |
type Game struct { | |
lines [][4]float64 | |
} | |
func (g *Game) Update() error { | |
return nil | |
} | |
func (g *Game) boxCollideSweep(x, y, w, h, dx, dy float64) (bool, float64) { | |
offsets := []float64{} | |
// log.Println(x, y, w, h, dx, dy) | |
for _, l := range g.lines { | |
coll, offset := SweepRectLine2(x, y, w, h, dx, dy, l[2], l[3], l[0], l[1]) | |
if coll { | |
offsets = append(offsets, offset) | |
} | |
} | |
if len(offsets) == 0 { | |
return false, 0 | |
} | |
sort.Float64s(offsets) | |
return true, offsets[0] | |
} | |
func (g *Game) Draw(screen *ebiten.Image) { | |
screen.Fill(color.RGBA{R: 255, G: 255, B: 255, A: 255}) | |
for _, l := range g.lines { | |
ebitenutil.DrawLine(screen, l[0], l[1], l[2], l[3], color.RGBA{A: 255}) | |
} | |
mx, my := ebiten.CursorPosition() | |
coll, offset := g.boxCollideSweep(400, 300, 10, 40, float64(mx)-400, float64(my)-300) | |
col := color.RGBA{G: 255, A: 255} | |
if coll { | |
col.G, col.R, col.B = 0, 255, uint8(offset) | |
} | |
ebitenutil.DrawRect(screen, 400-5, 300-20, 10, 40, color.RGBA{B: 255, A: 100}) | |
ebitenutil.DrawLine(screen, 400, 300, float64(mx), float64(my), color.RGBA{B: 255, A: 100}) | |
ebitenutil.DrawRect(screen, float64(mx)-5, float64(my)-20, 10, 40, col) | |
if offset > 0 { | |
// log.Println(offset) | |
ebitenutil.DrawRect(screen, 400-5+(float64(mx)-400)*offset, 300-20+(float64(my)-300)*offset, 10, 40, color.RGBA{B: 255, A: 100}) | |
} | |
} | |
func (g *Game) Layout(outsideWidth, outsideHeight int) (int, int) { | |
return outsideWidth, outsideHeight | |
} | |
func main() { | |
log.Println("start") | |
game := &Game{ | |
lines: [][4]float64{ | |
{10, 590, 790, 590}, | |
{10, 590, 10, 300}, | |
{790, 590, 790, 300}, | |
{300, 400, 380, 400}, | |
{300, 400, 200, 370}, | |
{500, 300, 600, 370}, | |
}, | |
} | |
// Specify the window size as you like. Here, a doubled size is specified. | |
ebiten.SetWindowSize(800, 600) | |
ebiten.SetWindowTitle("Platformer") | |
// Call ebiten.RunGame to start your game loop. | |
if err := ebiten.RunGame(game); err != nil { | |
log.Fatal(err) | |
} | |
} | |
func SweepRectLine2(rectX, rectY, rectW, rectH, rectHSpeed, rectVSpeed, lineX1, lineY1, lineX2, lineY2 float64) (bool, float64) { | |
outVel := [2]float64{} | |
// hitNormal := [2]float64{} | |
lineNX, lineNY := lineX2-lineX1, lineY2-lineY1 | |
// lineMinX, lineMaxX, lineMinY, lineMaxY := math.Min(lineX1, lineX2), math.Max(lineX1, lineX2), math.Min(lineY1, lineY2), math.Max(lineY1, lineY2) | |
var lineMinX, lineMaxX, lineMinY, lineMaxY float64 | |
if lineNX > 0 { | |
lineMinX, lineMaxX = lineX1, lineX2 | |
} else { | |
lineMinX, lineMaxX = lineX2, lineX1 | |
} | |
if lineNY > 0 { | |
lineMinY, lineMaxY = lineY1, lineY2 | |
} else { | |
lineMinY, lineMaxY = lineY2, lineY1 | |
} | |
r := (rectW/2)*math.Abs(lineNX) + (rectH/2)*math.Abs(lineNY) //radius to Line | |
boxProj := (lineX1-rectX)*lineNX + (lineY1-rectY)*lineNY | |
velProj := rectHSpeed*lineNX + rectVSpeed*lineNY | |
if velProj < 0 { | |
r *= -1 | |
} | |
hitTime := math.Max((boxProj-r)/velProj, 0) | |
outTime := math.Min((boxProj+r)/velProj, 1) | |
// log.Println("start", hitTime, outTime) | |
rectXMax, rectXMin := rectX+rectW/2, rectX-rectW/2 | |
if rectHSpeed < 0 { // left | |
if rectXMax < lineMinX { | |
return false, 0 | |
} | |
hitTime = math.Max((lineMaxX-rectXMin)/rectHSpeed, hitTime) | |
outTime = math.Min((lineMinX-rectXMax)/rectHSpeed, outTime) | |
} else if rectHSpeed > 0 { // right | |
if rectXMin > lineMaxX { | |
return false, 0 | |
} | |
hitTime = math.Max((lineMinX-rectXMax)/rectHSpeed, hitTime) | |
outTime = math.Min((lineMaxX-rectXMin)/rectHSpeed, outTime) | |
// log.Println("right", hitTime, outTime) | |
} else { | |
if lineMinX > rectXMax || lineMaxX < rectXMin { | |
return false, 0 | |
} | |
} | |
if hitTime > outTime { | |
return false, 0 | |
} | |
rectYMax, rectYMin := rectY+rectH/2, rectY-rectH/2 | |
if rectVSpeed < 0 { // up | |
if rectYMax < lineMinY { | |
return false, 0 | |
} | |
hitTime = math.Max((lineMaxY-rectYMin)/rectVSpeed, hitTime) | |
outTime = math.Min((lineMinY-rectYMax)/rectVSpeed, outTime) | |
} else if rectVSpeed > 0 { // down | |
if rectYMin > lineMaxY { | |
return false, 0 | |
} | |
hitTime = math.Max((lineMinY-rectYMax)/rectVSpeed, hitTime) | |
outTime = math.Min((lineMaxY-rectYMin)/rectVSpeed, outTime) | |
} else { | |
if lineMinY > rectYMax || lineMaxY < rectYMin { | |
return false, 0 | |
} | |
} | |
if hitTime > outTime { | |
return false, 0 | |
} | |
outVel[0] = rectHSpeed * hitTime | |
outVel[1] = rectVSpeed * hitTime | |
return true, hitTime | |
} |
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