improve skeletal shading, fixes, tests

src/main/java/de/bixilon/minosoft/gui/rendering/entities/model/human/animator/ArmAnimator.kt

@@ -66,7 +66,7 @@ class ArmAnimator(
 
             val z = (1.0f - (swing * 1.2f)) * (-20.0f).rad // TODO: animate the 1.2f back to 1.0f
             val y = sin * 0.2f
-            val x = (sin * 1.2f + sin) * -0.65f
+            val x = sin * -1.4f
 
 
             transform.value.rotateRadAssign(Vec3(x, y, if (arm == Arms.RIGHT) z else -z))

src/main/resources/assets/minosoft/rendering/shader/includes/skeletal/shade.glsl

@@ -26,7 +26,7 @@ vec3 decodeNormal(uint normal) {
 
 vec3 transformNormal(vec3 normal, mat4 transform) {
     //  return normalize(mat3(transpose(inverse(transform))) * normal);
-    return mat3(transform) * normal;
+    return normalize(mat3(transform) * normal);
 }
 
 float interpolateShade(float delta, float max) {

src/test/java/de/bixilon/minosoft/gui/rendering/models/block/state/baked/SkeletalShadeTest.kt

@@ -13,6 +13,9 @@
 
 package de.bixilon.minosoft.gui.rendering.models.block.state.baked
 
+import de.bixilon.kotlinglm.func.rad
+import de.bixilon.kotlinglm.mat3x3.Mat3
+import de.bixilon.kotlinglm.mat4x4.Mat4
 import de.bixilon.kotlinglm.vec3.Vec3
 import org.junit.jupiter.api.Test
 import kotlin.math.abs
@@ -50,6 +53,11 @@ class SkeletalShadeTest {
         return x + y + z
     }
 
+    fun transformNormal(normal: Vec3, transform: Mat4): Vec3 {
+        //  return normalize(mat3(transpose(inverse(transform))) * normal);
+        return (Mat3(transform) * normal).normalizeAssign()
+    }
+
     @Test
     fun up() {
         assertEquals(1.0f, getShade(Vec3(0, 1, 0)))
@@ -105,7 +113,63 @@ class SkeletalShadeTest {
         assertEquals(0.94f, getShade(Vec3(1, 1, 1)))
     }
 
-    // TODO: test transforming
+
+    private fun assertEquals(actual: Vec3, expected: Vec3) {
+        val delta = actual - expected
+        if (delta.length2() < 0.01f) return
+        throw AssertionError("Expected $expected, but got $actual")
+    }
+
+    @Test
+    fun `transform rotate Y 90deg`() {
+        val transform = Mat4().rotateYassign(90.0f.rad)
+        val normal = Vec3(0.0f, 1.0f, 0.0f)
+        assertEquals(transformNormal(normal, transform), Vec3(0.0f, 1.0f, 0.0f))
+    }
+
+    @Test
+    fun `transform rotate Y 180deg`() {
+        val transform = Mat4().rotateYassign(180.0f.rad)
+        val normal = Vec3(0.0f, -1.0f, 0.0f)
+        assertEquals(transformNormal(normal, transform), Vec3(0.0f, -1.0f, 0.0f))
+    }
+
+
+    @Test
+    fun `transform rotate Y 90deg 2`() {
+        val transform = Mat4().rotateYassign(90.0f.rad)
+        val normal = Vec3(1.0f, 0.0f, 0.0f)
+        assertEquals(transformNormal(normal, transform), Vec3(0.0f, 0.0f, -1.0f))
+    }
+
+    @Test
+    fun `transform rotate Y 180deg 2`() {
+        val transform = Mat4().rotateYassign(180.0f.rad)
+        val normal = Vec3(1.0f, 0.0f, 0.0f)
+        assertEquals(transformNormal(normal, transform), Vec3(-1.0f, 0.0f, 0.0f))
+    }
+
+    @Test
+    fun `transform translated`() {
+        val transform = Mat4()
+            .translateAssign(Vec3(123, 456, 789))
+            .rotateYassign(180.0f.rad)
+        val normal = Vec3(1.0f, 0.0f, 0.0f)
+        assertEquals(transformNormal(normal, transform), Vec3(-1.0f, 0.0f, 0.0f))
+    }
+
+    @Test
+    fun `transform translated scaled`() {
+        val transform = Mat4()
+            .scaleAssign(0.4f)
+            .translateAssign(Vec3(123, 456, 789))
+            .rotateYassign(180.0f.rad)
+        val normal = Vec3(1.0f, 0.0f, 0.0f)
+        assertEquals(transformNormal(normal, transform), Vec3(-1.0f, 0.0f, 0.0f))
+    }
+
+    // TODO: test why shade is wrong sometimes
+
 
     private fun assertEquals(expected: Float, actual: Float) {
         if (abs(expected - actual) < 0.03f) return