hide gizmo handles depending on view angle

kool-engine · Feb 26, 2024 · 3dc74a8 · 3dc74a8
1 parent 9ef5053
commit 3dc74a8
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Showing 3 changed files with 128 additions and 35 deletions.
diff --git a/kool-core/src/commonMain/kotlin/de/fabmax/kool/modules/gizmo/AxisHandle.kt b/kool-core/src/commonMain/kotlin/de/fabmax/kool/modules/gizmo/AxisHandle.kt
@@ -1,9 +1,7 @@
 package de.fabmax.kool.modules.gizmo
 
 import de.fabmax.kool.input.Pointer
-import de.fabmax.kool.math.RayD
-import de.fabmax.kool.math.Vec3f
-import de.fabmax.kool.math.deg
+import de.fabmax.kool.math.*
 import de.fabmax.kool.modules.ksl.KslUnlitShader
 import de.fabmax.kool.pipeline.Attribute
 import de.fabmax.kool.pipeline.DepthCompareOp
@@ -12,6 +10,8 @@ import de.fabmax.kool.scene.MeshRayTest
 import de.fabmax.kool.scene.Node
 import de.fabmax.kool.scene.TrsTransformD
 import de.fabmax.kool.util.Color
+import kotlin.math.abs
+import kotlin.math.cos
 
 class AxisHandle(
     val color: Color,
@@ -33,6 +33,9 @@ class AxisHandle(
     private val mesh: Mesh = Mesh(Attribute.POSITIONS, Attribute.NORMALS, name = "${name}-mesh")
     private val coveredMesh: Mesh = Mesh(Attribute.POSITIONS, Attribute.NORMALS, name = "${name}-coveredMesh")
 
+    private var isHovered = false
+    private var alphaFactor = 1f
+
     init {
         transform = TrsTransformD().apply {
             rotation.set(axis.orientation)
@@ -48,7 +51,6 @@ class AxisHandle(
         coveredMesh.setupGeometry(handleShape, innerDistance, length, 0.015f, 0.07f)
         coveredMesh.setupShader(DepthCompareOp.ALWAYS)
         hitMesh.setupGeometry(HandleType.SPHERE, innerDistance, length, 0.07f, 0.15f)
-        setColors(colorIdle, coveredColorIdle)
 
         // hasChanged flag is usually cleared after mesh is drawn the first time, but hitMesh is never drawn
         // -> clear flag manually to avoid hitTest kd-tree being regenerated every frame
@@ -57,19 +59,49 @@ class AxisHandle(
         addNode(coveredMesh)
         addNode(mesh)
         addNode(hitMesh)
+
+        val camDelta = MutableVec3d()
+        val alphaThreshHigh = cos(5f.deg.rad)
+        val alphaThreshLow = cos(15f.deg.rad)
+
+        onUpdate {
+            modelMatD.transform(camDelta.set(Vec3d.ZERO), 1.0)
+            camDelta.subtract(it.camera.dataD.globalPos)
+            val cosAngle = abs(camDelta.norm() dot axis.axis).toFloat()
+            alphaFactor = if (cosAngle > alphaThreshLow) {
+                1f - smoothStep(alphaThreshLow, alphaThreshHigh, cosAngle)
+            } else {
+                1f
+            }
+
+            isVisible = alphaFactor > 0.01f
+            hitMesh.isPickable = isVisible
+            updateColors()
+        }
     }
 
-    private fun setColors(mainColor: Color, coveredColor: Color) {
+    private fun updateColors() {
+        var mainColor: Color = if (isHovered) color else colorIdle
+        var coveredColor: Color = if (isHovered) coveredColor else coveredColorIdle
+
+        if (alphaFactor > 0f && isHovered) {
+            alphaFactor = 1f
+        }
+        if (alphaFactor != 1f) {
+            mainColor = mainColor.withAlpha(mainColor.a * alphaFactor)
+            coveredColor = coveredColor.withAlpha(coveredColor.a * alphaFactor)
+        }
+
         (mesh.shader as KslUnlitShader).color = mainColor
         (coveredMesh.shader as KslUnlitShader).color = coveredColor
     }
 
     override fun onHover(pointer: Pointer, globalRay: RayD, gizmo: GizmoNode) {
-        setColors(color, coveredColor)
+        isHovered = true
     }
 
     override fun onHoverExit(gizmo: GizmoNode) {
-        setColors(colorIdle, coveredColorIdle)
+        isHovered = false
     }
 
     private fun Mesh.setupGeometry(

diff --git a/kool-core/src/commonMain/kotlin/de/fabmax/kool/modules/gizmo/AxisRotationHandle.kt b/kool-core/src/commonMain/kotlin/de/fabmax/kool/modules/gizmo/AxisRotationHandle.kt
@@ -1,9 +1,7 @@
 package de.fabmax.kool.modules.gizmo
 
 import de.fabmax.kool.input.Pointer
-import de.fabmax.kool.math.RayD
-import de.fabmax.kool.math.Vec3f
-import de.fabmax.kool.math.deg
+import de.fabmax.kool.math.*
 import de.fabmax.kool.modules.ksl.KslUnlitShader
 import de.fabmax.kool.pipeline.Attribute
 import de.fabmax.kool.pipeline.DepthCompareOp
@@ -12,6 +10,8 @@ import de.fabmax.kool.scene.MeshRayTest
 import de.fabmax.kool.scene.Node
 import de.fabmax.kool.scene.TrsTransformD
 import de.fabmax.kool.util.Color
+import kotlin.math.abs
+import kotlin.math.cos
 
 class AxisRotationHandle(
     val color: Color,
@@ -31,6 +31,9 @@ class AxisRotationHandle(
     private val mesh: Mesh = Mesh(Attribute.POSITIONS, Attribute.NORMALS, name = "${name}-mesh")
     private val coveredMesh: Mesh = Mesh(Attribute.POSITIONS, Attribute.NORMALS, name = "${name}-coveredMesh")
 
+    private var isHovered = false
+    private var alphaFactor = 1f
+
     init {
         transform = TrsTransformD().apply {
             rotation.set(axis.orientation)
@@ -46,7 +49,6 @@ class AxisRotationHandle(
         coveredMesh.setupGeometry(radius, 0.01f)
         coveredMesh.setupShader(DepthCompareOp.ALWAYS)
         hitMesh.setupGeometry(radius, 0.05f)
-        setColors(colorIdle, coveredColorIdle)
 
         // hasChanged flag is usually cleared after mesh is drawn the first time, but hitMesh is never drawn
         // -> clear flag manually to avoid hitTest kd-tree being regenerated every frame
@@ -55,13 +57,51 @@ class AxisRotationHandle(
         addNode(coveredMesh)
         addNode(mesh)
         addNode(hitMesh)
+
+        val camDelta = MutableVec3d()
+        val alphaThreshHigh = cos(75f.deg.rad)
+        val alphaThreshLow = cos(85f.deg.rad)
+
+        onUpdate {
+            modelMatD.transform(camDelta.set(Vec3d.ZERO), 1.0)
+            camDelta.subtract(it.camera.dataD.globalPos)
+            val cosAngle = abs(camDelta.norm() dot axis.axis).toFloat()
+            alphaFactor = if (cosAngle < alphaThreshHigh) {
+                smoothStep(alphaThreshLow, alphaThreshHigh, cosAngle)
+            } else {
+                1f
+            }
+
+            isVisible = alphaFactor > 0.01f
+            hitMesh.isPickable = isVisible
+            updateColors()
+        }
     }
 
-    private fun setColors(mainColor: Color, coveredColor: Color) {
+    private fun updateColors() {
+        var mainColor: Color = if (isHovered) color else colorIdle
+        var coveredColor: Color = if (isHovered) coveredColor else coveredColorIdle
+
+        if (alphaFactor > 0f && isHovered) {
+            alphaFactor = 1f
+        }
+        if (alphaFactor != 1f) {
+            mainColor = mainColor.withAlpha(mainColor.a * alphaFactor)
+            coveredColor = coveredColor.withAlpha(coveredColor.a * alphaFactor)
+        }
+
         (mesh.shader as KslUnlitShader).color = mainColor
         (coveredMesh.shader as KslUnlitShader).color = coveredColor
     }
 
+    override fun onHover(pointer: Pointer, globalRay: RayD, gizmo: GizmoNode) {
+        isHovered = true
+    }
+
+    override fun onHoverExit(gizmo: GizmoNode) {
+        isHovered = false
+    }
+
     private fun Mesh.setupGeometry(
         orbitRadius: Float,
         geomRadius: Float,
@@ -95,12 +135,4 @@ class AxisRotationHandle(
             color { uniformColor() }
         }
     }
-
-    override fun onHover(pointer: Pointer, globalRay: RayD, gizmo: GizmoNode) {
-        setColors(color, coveredColor)
-    }
-
-    override fun onHoverExit(gizmo: GizmoNode) {
-        setColors(colorIdle, coveredColorIdle)
-    }
 }
diff --git a/kool-core/src/commonMain/kotlin/de/fabmax/kool/modules/gizmo/PlaneHandle.kt b/kool-core/src/commonMain/kotlin/de/fabmax/kool/modules/gizmo/PlaneHandle.kt
@@ -1,9 +1,7 @@
 package de.fabmax.kool.modules.gizmo
 
 import de.fabmax.kool.input.Pointer
-import de.fabmax.kool.math.RayD
-import de.fabmax.kool.math.Vec3f
-import de.fabmax.kool.math.deg
+import de.fabmax.kool.math.*
 import de.fabmax.kool.modules.ksl.KslUnlitShader
 import de.fabmax.kool.pipeline.Attribute
 import de.fabmax.kool.pipeline.CullMethod
@@ -17,6 +15,7 @@ import de.fabmax.kool.scene.geometry.PrimitiveType
 import de.fabmax.kool.util.Color
 import kotlin.math.abs
 import kotlin.math.atan2
+import kotlin.math.cos
 import kotlin.math.max
 
 class PlaneHandle(
@@ -38,6 +37,9 @@ class PlaneHandle(
     private val coveredMesh: Mesh
     private val lineMesh: Mesh
 
+    private var isHovered = false
+    private var alphaFactor = 1f
+
     init {
         transform = TrsTransformD().apply {
             rotation.set(axis.orientation)
@@ -55,21 +57,56 @@ class PlaneHandle(
         lineMesh = Mesh(IndexedVertexList(Attribute.POSITIONS, primitiveType = PrimitiveType.LINES), name = "${name}-lineMesh")
         lineMesh.makeOutline(size, innerDistance, mesh)
 
-
-        setColors(colorIdle, coveredColorIdle)
-
         addNode(coveredMesh)
         addNode(mesh)
         addNode(lineMesh)
+
+        val camDelta = MutableVec3d()
+        val alphaThreshHigh = cos(75f.deg.rad)
+        val alphaThreshLow = cos(85f.deg.rad)
+
+        onUpdate {
+            modelMatD.transform(camDelta.set(Vec3d.ZERO), 1.0)
+            camDelta.subtract(it.camera.dataD.globalPos)
+            val cosAngle = abs(camDelta.norm() dot axis.axis).toFloat()
+            alphaFactor = if (cosAngle < alphaThreshHigh) {
+                smoothStep(alphaThreshLow, alphaThreshHigh, cosAngle)
+            } else {
+                1f
+            }
+
+            isVisible = alphaFactor > 0.01f
+            mesh.isPickable = isVisible
+            updateColors()
+        }
     }
 
-    private fun setColors(mainColor: Color, coveredColor: Color) {
+    private fun updateColors() {
+        var mainColor: Color = if (isHovered) color else colorIdle
+        var coveredColor: Color = if (isHovered) coveredColor else coveredColorIdle
+
+        if (alphaFactor > 0f && isHovered) {
+            alphaFactor = 1f
+        }
+        if (alphaFactor != 1f) {
+            mainColor = mainColor.withAlpha(mainColor.a * alphaFactor)
+            coveredColor = coveredColor.withAlpha(coveredColor.a * alphaFactor)
+        }
+
         val planeAlpha = mainColor.a * 0.3f
         (mesh.shader as KslUnlitShader).color = mainColor.withAlpha(planeAlpha)
         (coveredMesh.shader as KslUnlitShader).color = coveredColor
         (lineMesh.shader as KslUnlitShader).color = mainColor
     }
 
+    override fun onHover(pointer: Pointer, globalRay: RayD, gizmo: GizmoNode) {
+        isHovered = true
+    }
+
+    override fun onHoverExit(gizmo: GizmoNode) {
+        isHovered = false
+    }
+
     private fun Mesh.setup(
         planeSize: Float,
         innerDistance: Float,
@@ -119,12 +156,4 @@ class PlaneHandle(
             color { uniformColor(color) }
         }
     }
-
-    override fun onHover(pointer: Pointer, globalRay: RayD, gizmo: GizmoNode) {
-        setColors(color, coveredColor)
-    }
-
-    override fun onHoverExit(gizmo: GizmoNode) {
-        setColors(colorIdle, coveredColorIdle)
-    }
 }