From 392fe90b11287faee831a9167e00588d1cea760a Mon Sep 17 00:00:00 2001
From: Jacek Olszak <jacekolszak@gmail.com>
Date: Wed, 13 Feb 2019 14:39:47 +0100
Subject: [PATCH] #159 Test whether
Matrix.Unprejected(Matrix.Projected(vertex)) == vertex
---
geometry_test.go | 49 +++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 42 insertions(+), 7 deletions(-)
diff --git a/geometry_test.go b/geometry_test.go
index 9eb8367..8ac01c3 100644
--- a/geometry_test.go
+++ b/geometry_test.go
@@ -81,7 +81,7 @@ func TestResizeRect(t *testing.T) {
}
func TestMatrix_Unproject(t *testing.T) {
- const delta = 4e-16
+ const delta = 1e-15
t.Run("for rotated matrix", func(t *testing.T) {
matrix := pixel.IM.
Rotated(pixel.ZV, math.Pi/2)
@@ -91,16 +91,16 @@ func TestMatrix_Unproject(t *testing.T) {
})
t.Run("for moved matrix", func(t *testing.T) {
matrix := pixel.IM.
- Moved(pixel.V(5, 5))
- unprojected := matrix.Unproject(pixel.V(0, 0))
- assert.InDelta(t, unprojected.X, -5, delta)
- assert.InDelta(t, unprojected.Y, -5, delta)
+ 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(4, 4))
- assert.InDelta(t, unprojected.X, 2, delta)
+ 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) {
@@ -120,6 +120,41 @@ func TestMatrix_Unproject(t *testing.T) {
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) {
+ matrices := [...]pixel.Matrix{
+ pixel.IM,
+ pixel.IM.Scaled(pixel.ZV, 0.5),
+ pixel.IM.Scaled(pixel.ZV, 2),
+ pixel.IM.Rotated(pixel.ZV, math.Pi/4),
+ pixel.IM.Moved(pixel.V(0.5, 1)),
+ pixel.IM.Moved(pixel.V(-1, -0.5)),
+ pixel.IM.Scaled(pixel.ZV, 0.5).Rotated(pixel.ZV, math.Pi/4),
+ pixel.IM.Scaled(pixel.ZV, 0.5).Rotated(pixel.ZV, math.Pi/4).Moved(pixel.V(1, 2)),
+ 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 _, matrix := range matrices {
+ for _, vertex := range vertices {
+ testCase := fmt.Sprintf("for matrix %v and vertex %v", matrix, 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)
--
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