go-opengl-pixel/geometry_test.go

693 lines
20 KiB
Go

package pixel_test
import (
"fmt"
"math"
"reflect"
"testing"
"github.com/faiface/pixel"
"github.com/stretchr/testify/assert"
)
func TestRect_Resize(t *testing.T) {
type rectTestTransform struct {
name string
f func(pixel.Rect) pixel.Rect
}
// rectangles
squareAroundOrigin := pixel.R(-10, -10, 10, 10)
squareAround2020 := pixel.R(10, 10, 30, 30)
rectangleAroundOrigin := pixel.R(-20, -10, 20, 10)
rectangleAround2020 := pixel.R(0, 10, 40, 30)
// resize transformations
resizeByHalfAroundCenter := rectTestTransform{"by half around center", func(rect pixel.Rect) pixel.Rect {
return rect.Resized(rect.Center(), rect.Size().Scaled(0.5))
}}
resizeByHalfAroundMin := rectTestTransform{"by half around Min", func(rect pixel.Rect) pixel.Rect {
return rect.Resized(rect.Min, rect.Size().Scaled(0.5))
}}
resizeByHalfAroundMax := rectTestTransform{"by half around Max", func(rect pixel.Rect) pixel.Rect {
return rect.Resized(rect.Max, rect.Size().Scaled(0.5))
}}
resizeByHalfAroundMiddleOfLeftSide := rectTestTransform{"by half around middle of left side", func(rect pixel.Rect) pixel.Rect {
return rect.Resized(pixel.V(rect.Min.X, rect.Center().Y), rect.Size().Scaled(0.5))
}}
resizeByHalfAroundOrigin := rectTestTransform{"by half around the origin", func(rect pixel.Rect) pixel.Rect {
return rect.Resized(pixel.ZV, rect.Size().Scaled(0.5))
}}
testCases := []struct {
input pixel.Rect
transform rectTestTransform
answer pixel.Rect
}{
{squareAroundOrigin, resizeByHalfAroundCenter, pixel.R(-5, -5, 5, 5)},
{squareAround2020, resizeByHalfAroundCenter, pixel.R(15, 15, 25, 25)},
{rectangleAroundOrigin, resizeByHalfAroundCenter, pixel.R(-10, -5, 10, 5)},
{rectangleAround2020, resizeByHalfAroundCenter, pixel.R(10, 15, 30, 25)},
{squareAroundOrigin, resizeByHalfAroundMin, pixel.R(-10, -10, 0, 0)},
{squareAround2020, resizeByHalfAroundMin, pixel.R(10, 10, 20, 20)},
{rectangleAroundOrigin, resizeByHalfAroundMin, pixel.R(-20, -10, 0, 0)},
{rectangleAround2020, resizeByHalfAroundMin, pixel.R(0, 10, 20, 20)},
{squareAroundOrigin, resizeByHalfAroundMax, pixel.R(0, 0, 10, 10)},
{squareAround2020, resizeByHalfAroundMax, pixel.R(20, 20, 30, 30)},
{rectangleAroundOrigin, resizeByHalfAroundMax, pixel.R(0, 0, 20, 10)},
{rectangleAround2020, resizeByHalfAroundMax, pixel.R(20, 20, 40, 30)},
{squareAroundOrigin, resizeByHalfAroundMiddleOfLeftSide, pixel.R(-10, -5, 0, 5)},
{squareAround2020, resizeByHalfAroundMiddleOfLeftSide, pixel.R(10, 15, 20, 25)},
{rectangleAroundOrigin, resizeByHalfAroundMiddleOfLeftSide, pixel.R(-20, -5, 0, 5)},
{rectangleAround2020, resizeByHalfAroundMiddleOfLeftSide, pixel.R(0, 15, 20, 25)},
{squareAroundOrigin, resizeByHalfAroundOrigin, pixel.R(-5, -5, 5, 5)},
{squareAround2020, resizeByHalfAroundOrigin, pixel.R(5, 5, 15, 15)},
{rectangleAroundOrigin, resizeByHalfAroundOrigin, pixel.R(-10, -5, 10, 5)},
{rectangleAround2020, resizeByHalfAroundOrigin, pixel.R(0, 5, 20, 15)},
}
for _, testCase := range testCases {
t.Run(fmt.Sprintf("Resize %v %s", testCase.input, testCase.transform.name), func(t *testing.T) {
testResult := testCase.transform.f(testCase.input)
if testResult != testCase.answer {
t.Errorf("Got: %v, wanted: %v\n", testResult, testCase.answer)
}
})
}
}
func TestMatrix_Unproject(t *testing.T) {
const delta = 1e-15
t.Run("for rotated matrix", func(t *testing.T) {
matrix := pixel.IM.
Rotated(pixel.ZV, math.Pi/2)
unprojected := matrix.Unproject(pixel.V(0, 1))
assert.InDelta(t, unprojected.X, 1, delta)
assert.InDelta(t, unprojected.Y, 0, delta)
})
t.Run("for moved matrix", func(t *testing.T) {
matrix := pixel.IM.
Moved(pixel.V(1, 2))
unprojected := matrix.Unproject(pixel.V(2, 5))
assert.InDelta(t, unprojected.X, 1, delta)
assert.InDelta(t, unprojected.Y, 3, delta)
})
t.Run("for scaled matrix", func(t *testing.T) {
matrix := pixel.IM.
Scaled(pixel.ZV, 2)
unprojected := matrix.Unproject(pixel.V(2, 4))
assert.InDelta(t, unprojected.X, 1, delta)
assert.InDelta(t, unprojected.Y, 2, delta)
})
t.Run("for scaled, rotated and moved matrix", func(t *testing.T) {
matrix := pixel.IM.
Scaled(pixel.ZV, 2).
Rotated(pixel.ZV, math.Pi/2).
Moved(pixel.V(2, 2))
unprojected := matrix.Unproject(pixel.V(-2, 6))
assert.InDelta(t, unprojected.X, 2, delta)
assert.InDelta(t, unprojected.Y, 2, delta)
})
t.Run("for rotated and moved matrix", func(t *testing.T) {
matrix := pixel.IM.
Rotated(pixel.ZV, math.Pi/2).
Moved(pixel.V(1, 1))
unprojected := matrix.Unproject(pixel.V(1, 2))
assert.InDelta(t, unprojected.X, 1, delta)
assert.InDelta(t, unprojected.Y, 0, delta)
})
t.Run("for projected vertices using all kinds of matrices", func(t *testing.T) {
namedMatrices := map[string]pixel.Matrix{
"IM": pixel.IM,
"Scaled": pixel.IM.Scaled(pixel.ZV, 0.5),
"Scaled x 2": pixel.IM.Scaled(pixel.ZV, 2),
"Rotated": pixel.IM.Rotated(pixel.ZV, math.Pi/4),
"Moved": pixel.IM.Moved(pixel.V(0.5, 1)),
"Moved 2": pixel.IM.Moved(pixel.V(-1, -0.5)),
"Scaled and Rotated": pixel.IM.Scaled(pixel.ZV, 0.5).Rotated(pixel.ZV, math.Pi/4),
"Scaled, Rotated and Moved": pixel.IM.Scaled(pixel.ZV, 0.5).Rotated(pixel.ZV, math.Pi/4).Moved(pixel.V(1, 2)),
"Rotated and Moved": pixel.IM.Rotated(pixel.ZV, math.Pi/4).Moved(pixel.V(1, 2)),
}
vertices := [...]pixel.Vec{
pixel.V(0, 0),
pixel.V(5, 0),
pixel.V(5, 10),
pixel.V(0, 10),
pixel.V(-5, 10),
pixel.V(-5, 0),
pixel.V(-5, -10),
pixel.V(0, -10),
pixel.V(5, -10),
}
for matrixName, matrix := range namedMatrices {
for _, vertex := range vertices {
testCase := fmt.Sprintf("for matrix %s and vertex %v", matrixName, vertex)
t.Run(testCase, func(t *testing.T) {
projected := matrix.Project(vertex)
unprojected := matrix.Unproject(projected)
assert.InDelta(t, vertex.X, unprojected.X, delta)
assert.InDelta(t, vertex.Y, unprojected.Y, delta)
})
}
}
})
t.Run("for singular matrix", func(t *testing.T) {
matrix := pixel.Matrix{0, 0, 0, 0, 0, 0}
unprojected := matrix.Unproject(pixel.ZV)
assert.True(t, math.IsNaN(unprojected.X))
assert.True(t, math.IsNaN(unprojected.Y))
})
}
func TestC(t *testing.T) {
type args struct {
radius float64
center pixel.Vec
}
tests := []struct {
name string
args args
want pixel.Circle
}{
{
name: "C(): positive radius",
args: args{radius: 10, center: pixel.ZV},
want: pixel.Circle{Radius: 10, Center: pixel.ZV},
},
{
name: "C(): zero radius",
args: args{radius: 0, center: pixel.ZV},
want: pixel.Circle{Radius: 0, Center: pixel.ZV},
},
{
name: "C(): negative radius",
args: args{radius: -5, center: pixel.ZV},
want: pixel.Circle{Radius: -5, Center: pixel.ZV},
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
if got := pixel.C(tt.args.center, tt.args.radius); !reflect.DeepEqual(got, tt.want) {
t.Errorf("C() = %v, want %v", got, tt.want)
}
})
}
}
func TestCircle_String(t *testing.T) {
type fields struct {
radius float64
center pixel.Vec
}
tests := []struct {
name string
fields fields
want string
}{
{
name: "Circle.String(): positive radius",
fields: fields{radius: 10, center: pixel.ZV},
want: "Circle(Vec(0, 0), 10.00)",
},
{
name: "Circle.String(): zero radius",
fields: fields{radius: 0, center: pixel.ZV},
want: "Circle(Vec(0, 0), 0.00)",
},
{
name: "Circle.String(): negative radius",
fields: fields{radius: -5, center: pixel.ZV},
want: "Circle(Vec(0, 0), -5.00)",
},
{
name: "Circle.String(): irrational radius",
fields: fields{radius: math.Pi, center: pixel.ZV},
want: "Circle(Vec(0, 0), 3.14)",
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
c := pixel.C(tt.fields.center, tt.fields.radius)
if got := c.String(); got != tt.want {
t.Errorf("Circle.String() = %v, want %v", got, tt.want)
}
})
}
}
func TestCircle_Norm(t *testing.T) {
type fields struct {
radius float64
center pixel.Vec
}
tests := []struct {
name string
fields fields
want pixel.Circle
}{
{
name: "Circle.Norm(): positive radius",
fields: fields{radius: 10, center: pixel.ZV},
want: pixel.C(pixel.ZV, 10),
},
{
name: "Circle.Norm(): zero radius",
fields: fields{radius: 0, center: pixel.ZV},
want: pixel.C(pixel.ZV, 0),
},
{
name: "Circle.Norm(): negative radius",
fields: fields{radius: -5, center: pixel.ZV},
want: pixel.C(pixel.ZV, 5),
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
c := pixel.C(tt.fields.center, tt.fields.radius)
if got := c.Norm(); !reflect.DeepEqual(got, tt.want) {
t.Errorf("Circle.Norm() = %v, want %v", got, tt.want)
}
})
}
}
func TestCircle_Area(t *testing.T) {
type fields struct {
radius float64
center pixel.Vec
}
tests := []struct {
name string
fields fields
want float64
}{
{
name: "Circle.Area(): positive radius",
fields: fields{radius: 10, center: pixel.ZV},
want: 100 * math.Pi,
},
{
name: "Circle.Area(): zero radius",
fields: fields{radius: 0, center: pixel.ZV},
want: 0,
},
{
name: "Circle.Area(): negative radius",
fields: fields{radius: -5, center: pixel.ZV},
want: 25 * math.Pi,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
c := pixel.C(tt.fields.center, tt.fields.radius)
if got := c.Area(); got != tt.want {
t.Errorf("Circle.Area() = %v, want %v", got, tt.want)
}
})
}
}
func TestCircle_Moved(t *testing.T) {
type fields struct {
radius float64
center pixel.Vec
}
type args struct {
delta pixel.Vec
}
tests := []struct {
name string
fields fields
args args
want pixel.Circle
}{
{
name: "Circle.Moved(): positive movement",
fields: fields{radius: 10, center: pixel.ZV},
args: args{delta: pixel.V(10, 20)},
want: pixel.C(pixel.V(10, 20), 10),
},
{
name: "Circle.Moved(): zero movement",
fields: fields{radius: 10, center: pixel.ZV},
args: args{delta: pixel.ZV},
want: pixel.C(pixel.V(0, 0), 10),
},
{
name: "Circle.Moved(): negative movement",
fields: fields{radius: 10, center: pixel.ZV},
args: args{delta: pixel.V(-5, -10)},
want: pixel.C(pixel.V(-5, -10), 10),
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
c := pixel.C(tt.fields.center, tt.fields.radius)
if got := c.Moved(tt.args.delta); !reflect.DeepEqual(got, tt.want) {
t.Errorf("Circle.Moved() = %v, want %v", got, tt.want)
}
})
}
}
func TestCircle_Resized(t *testing.T) {
type fields struct {
radius float64
center pixel.Vec
}
type args struct {
radiusDelta float64
}
tests := []struct {
name string
fields fields
args args
want pixel.Circle
}{
{
name: "Circle.Resized(): positive delta",
fields: fields{radius: 10, center: pixel.ZV},
args: args{radiusDelta: 5},
want: pixel.C(pixel.V(0, 0), 15),
},
{
name: "Circle.Resized(): zero delta",
fields: fields{radius: 10, center: pixel.ZV},
args: args{radiusDelta: 0},
want: pixel.C(pixel.V(0, 0), 10),
},
{
name: "Circle.Resized(): negative delta",
fields: fields{radius: 10, center: pixel.ZV},
args: args{radiusDelta: -5},
want: pixel.C(pixel.V(0, 0), 5),
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
c := pixel.C(tt.fields.center, tt.fields.radius)
if got := c.Resized(tt.args.radiusDelta); !reflect.DeepEqual(got, tt.want) {
t.Errorf("Circle.Resized() = %v, want %v", got, tt.want)
}
})
}
}
func TestCircle_Contains(t *testing.T) {
type fields struct {
radius float64
center pixel.Vec
}
type args struct {
u pixel.Vec
}
tests := []struct {
name string
fields fields
args args
want bool
}{
{
name: "Circle.Contains(): point on cicles' center",
fields: fields{radius: 10, center: pixel.ZV},
args: args{u: pixel.ZV},
want: true,
},
{
name: "Circle.Contains(): point offcenter",
fields: fields{radius: 10, center: pixel.V(5, 0)},
args: args{u: pixel.ZV},
want: true,
},
{
name: "Circle.Contains(): point on circumference",
fields: fields{radius: 10, center: pixel.V(10, 0)},
args: args{u: pixel.ZV},
want: true,
},
{
name: "Circle.Contains(): point outside circle",
fields: fields{radius: 10, center: pixel.V(15, 0)},
args: args{u: pixel.ZV},
want: false,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
c := pixel.C(tt.fields.center, tt.fields.radius)
if got := c.Contains(tt.args.u); got != tt.want {
t.Errorf("Circle.Contains() = %v, want %v", got, tt.want)
}
})
}
}
func TestCircle_Union(t *testing.T) {
type fields struct {
radius float64
center pixel.Vec
}
type args struct {
d pixel.Circle
}
tests := []struct {
name string
fields fields
args args
want pixel.Circle
}{
{
name: "Circle.Union(): overlapping circles",
fields: fields{radius: 5, center: pixel.ZV},
args: args{d: pixel.C(pixel.ZV, 5)},
want: pixel.C(pixel.ZV, 5),
},
{
name: "Circle.Union(): separate circles",
fields: fields{radius: 1, center: pixel.ZV},
args: args{d: pixel.C(pixel.V(0, 2), 1)},
want: pixel.C(pixel.V(0, 1), 2),
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
c := pixel.C(tt.fields.center, tt.fields.radius)
if got := c.Union(tt.args.d); !reflect.DeepEqual(got, tt.want) {
t.Errorf("Circle.Union() = %v, want %v", got, tt.want)
}
})
}
}
func TestCircle_Intersect(t *testing.T) {
type fields struct {
radius float64
center pixel.Vec
}
type args struct {
d pixel.Circle
}
tests := []struct {
name string
fields fields
args args
want pixel.Circle
}{
{
name: "Circle.Intersect(): intersecting circles",
fields: fields{radius: 1, center: pixel.ZV},
args: args{d: pixel.C(pixel.V(1, 0), 1)},
want: pixel.C(pixel.V(0.5, 0), 1),
},
{
name: "Circle.Intersect(): non-intersecting circles",
fields: fields{radius: 1, center: pixel.ZV},
args: args{d: pixel.C(pixel.V(3, 3), 1)},
want: pixel.C(pixel.V(1.5, 1.5), 0),
},
{
name: "Circle.Intersect(): first circle encompassing second",
fields: fields{radius: 10, center: pixel.ZV},
args: args{d: pixel.C(pixel.V(3, 3), 1)},
want: pixel.C(pixel.ZV, 10),
},
{
name: "Circle.Intersect(): second circle encompassing first",
fields: fields{radius: 1, center: pixel.V(-1, -4)},
args: args{d: pixel.C(pixel.ZV, 10)},
want: pixel.C(pixel.ZV, 10),
},
{
name: "Circle.Intersect(): matching circles",
fields: fields{radius: 1, center: pixel.ZV},
args: args{d: pixel.C(pixel.ZV, 1)},
want: pixel.C(pixel.ZV, 1),
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
c := pixel.C(
tt.fields.center,
tt.fields.radius,
)
if got := c.Intersect(tt.args.d); !reflect.DeepEqual(got, tt.want) {
t.Errorf("Circle.Intersect() = %v, want %v", got, tt.want)
}
})
}
}
func TestRect_IntersectCircle(t *testing.T) {
// closeEnough will shift the decimal point by the accuracy required, truncates the results and compares them.
// Effectively this compares two floats to a given decimal point.
// Example:
// closeEnough(100.125342432, 100.125, 2) == true
// closeEnough(math.Pi, 3.14, 2) == true
// closeEnough(0.1234, 0.1245, 3) == false
closeEnough := func(got, expected float64, decimalAccuracy int) bool {
gotShifted := got * math.Pow10(decimalAccuracy)
expectedShifted := expected * math.Pow10(decimalAccuracy)
return math.Trunc(gotShifted) == math.Trunc(expectedShifted)
}
type fields struct {
Min pixel.Vec
Max pixel.Vec
}
type args struct {
c pixel.Circle
}
tests := []struct {
name string
fields fields
args args
want pixel.Vec
}{
{
name: "Rect.IntersectCircle(): no overlap",
fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
args: args{c: pixel.C(pixel.V(50, 50), 1)},
want: pixel.ZV,
},
{
name: "Rect.IntersectCircle(): circle contains rect",
fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
args: args{c: pixel.C(pixel.V(5, 5), 10)},
want: pixel.V(-15, 0),
},
{
name: "Rect.IntersectCircle(): rect contains circle",
fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
args: args{c: pixel.C(pixel.V(5, 5), 1)},
want: pixel.V(-6, 0),
},
{
name: "Rect.IntersectCircle(): circle overlaps bottom-left corner",
fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
args: args{c: pixel.C(pixel.V(-0.5, -0.5), 1)},
want: pixel.V(-0.2, -0.2),
},
{
name: "Rect.IntersectCircle(): circle overlaps top-left corner",
fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
args: args{c: pixel.C(pixel.V(-0.5, 10.5), 1)},
want: pixel.V(-0.2, 0.2),
},
{
name: "Rect.IntersectCircle(): circle overlaps bottom-right corner",
fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
args: args{c: pixel.C(pixel.V(10.5, -0.5), 1)},
want: pixel.V(0.2, -0.2),
},
{
name: "Rect.IntersectCircle(): circle overlaps top-right corner",
fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
args: args{c: pixel.C(pixel.V(10.5, 10.5), 1)},
want: pixel.V(0.2, 0.2),
},
{
name: "Rect.IntersectCircle(): circle overlaps two corners",
fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
args: args{c: pixel.C(pixel.V(0, 5), 6)},
want: pixel.V(6, 0),
},
{
name: "Rect.IntersectCircle(): circle overlaps left edge",
fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
args: args{c: pixel.C(pixel.V(0, 5), 1)},
want: pixel.V(1, 0),
},
{
name: "Rect.IntersectCircle(): circle overlaps bottom edge",
fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
args: args{c: pixel.C(pixel.V(5, 0), 1)},
want: pixel.V(0, 1),
},
{
name: "Rect.IntersectCircle(): circle overlaps right edge",
fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
args: args{c: pixel.C(pixel.V(10, 5), 1)},
want: pixel.V(-1, 0),
},
{
name: "Rect.IntersectCircle(): circle overlaps top edge",
fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
args: args{c: pixel.C(pixel.V(5, 10), 1)},
want: pixel.V(0, -1),
},
{
name: "Rect.IntersectCircle(): edge is tangent of left side",
fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
args: args{c: pixel.C(pixel.V(-1, 5), 1)},
want: pixel.ZV,
},
{
name: "Rect.IntersectCircle(): edge is tangent of top side",
fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
args: args{c: pixel.C(pixel.V(5, -1), 1)},
want: pixel.ZV,
},
{
name: "Rect.IntersectCircle(): circle above rectangle",
fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
args: args{c: pixel.C(pixel.V(5, 12), 1)},
want: pixel.ZV,
},
{
name: "Rect.IntersectCircle(): circle below rectangle",
fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
args: args{c: pixel.C(pixel.V(5, -2), 1)},
want: pixel.ZV,
},
{
name: "Rect.IntersectCircle(): circle left of rectangle",
fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
args: args{c: pixel.C(pixel.V(-1, 5), 1)},
want: pixel.ZV,
},
{
name: "Rect.IntersectCircle(): circle right of rectangle",
fields: fields{Min: pixel.ZV, Max: pixel.V(10, 10)},
args: args{c: pixel.C(pixel.V(11, 5), 1)},
want: pixel.ZV,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
r := pixel.Rect{
Min: tt.fields.Min,
Max: tt.fields.Max,
}
got := r.IntersectCircle(tt.args.c)
if !closeEnough(got.X, tt.want.X, 2) || !closeEnough(got.Y, tt.want.Y, 2) {
t.Errorf("Rect.IntersectCircle() = %v, want %v", got, tt.want)
}
})
}
}