From c1531c3d99b19032040018b9414263b0d3000147 Mon Sep 17 00:00:00 2001
From: Sven Göthel <sgothel@jausoft.com>
Date: Sat, 20 Jan 2024 05:01:38 +0100
Subject: Graph Clipping: Use Frustum Clipping using AABBox -> Mv transformed
 Cube -> Frustum mapping + GraphUI Support

AABBox clipping naturally couldn't be transformed into 3D Model-View (Mv) Space,
as it is axis aligned and only provided 2 points (min/max).

Therefor we map the Group's AABBox to a 8-point Cube,
perform the Mv-transformation and then produce the 6-plane Frustum.

As before, we cull fully outside shapes within the Group's draw method
and perform fragment clipping with same Frustum planes in the shader.

With clipping enabled, the 3D z-axis getBounds() depth
will be slightly increased for functional Frustum operation.
This is also done for setFixedSize(Vec2f).

The Frustum planes are copied to the Graph shader
via float[4*6] -> uniform vec4  gcu_ClipFrustum[6]; // L, R, B, T, N, F each {n.x, n.y, n.z, d}

+++

Concludes related work of below commits
- 1040bed4ecc6f4598ea459f1073a9240583fc3c3
- 5cca51e32999a882e2a5f00cb45ecafc824ffd86
---
 .../com/jogamp/graph/curve/opengl/RenderState.java | 26 +++++++++++++++-------
 1 file changed, 18 insertions(+), 8 deletions(-)

(limited to 'src/jogl/classes/com/jogamp/graph/curve/opengl/RenderState.java')

diff --git a/src/jogl/classes/com/jogamp/graph/curve/opengl/RenderState.java b/src/jogl/classes/com/jogamp/graph/curve/opengl/RenderState.java
index ed5bcb110..d6be9e07b 100644
--- a/src/jogl/classes/com/jogamp/graph/curve/opengl/RenderState.java
+++ b/src/jogl/classes/com/jogamp/graph/curve/opengl/RenderState.java
@@ -39,7 +39,7 @@ import jogamp.graph.curve.opengl.shader.UniformNames;
 
 import com.jogamp.graph.curve.Region;
 import com.jogamp.math.Vec4f;
-import com.jogamp.math.geom.AABBox;
+import com.jogamp.math.geom.Frustum;
 import com.jogamp.math.util.PMVMatrix4f;
 import com.jogamp.opengl.util.GLArrayDataWrapper;
 import com.jogamp.opengl.util.glsl.ShaderProgram;
@@ -102,8 +102,9 @@ public class RenderState {
     private int aaQuality;
     /** Default pass2 AA sample count {@value} for Graph Region AA {@link Region#getRenderModes() render-modes}: {@link Region#VBAA_RENDERING_BIT} or {@link Region#MSAA_RENDERING_BIT}. */
     private int sampleCount;
-    /** Optional clipping {@link AABBox}, which shall be pre-multiplied with the Mv-matrix. Null if unused. */
-    private AABBox clipBBox;
+    /** Optional clipping {@link Frustum}, which shall be pre-multiplied with the Mv-matrix. Null if unused. */
+    private final Frustum clipFrustum;
+    private boolean useClipFrustum;
     private int hintBitfield;
     private ShaderProgram sp;
 
@@ -205,7 +206,9 @@ public class RenderState {
         this.colorStaticBuffer = FloatBuffer.wrap(colorStatic);
         this.aaQuality = Region.DEFAULT_AA_QUALITY;
         this.sampleCount = Region.DEFAULT_AA_SAMPLE_COUNT;
-        this.clipBBox = null;
+        this.clipFrustum = new Frustum();
+        this.useClipFrustum = false;
+
         this.hintBitfield = 0;
         this.sp = null;
     }
@@ -281,10 +284,17 @@ public class RenderState {
     /** Returns pass2 AA sample count for Graph Region AA {@link Region#getRenderModes() render-modes}: {@link #VBAA_RENDERING_BIT} or {@link Region#MSAA_RENDERING_BIT}. */
     public final int getSampleCount() { return this.sampleCount; }
 
-    /** Set the optional clipping {@link AABBox}, which shall be pre-multiplied with the Mv-matrix or null to disable. */
-    public final void setClipBBox(final AABBox clipBBox) { this.clipBBox = clipBBox; }
-    /** Returns the optional Mv-premultiplied clipping {@link AABBox} or null if unused. */
-    public final AABBox getClipBBox() { return this.clipBBox; }
+    /** Set the optional clipping {@link Frustum}, which shall be pre-multiplied with the Mv-matrix or null to disable. */
+    public final void setClipFrustum(final Frustum clipFrustum) {
+        if( null != clipFrustum ) {
+            this.clipFrustum.set(clipFrustum);
+            this.useClipFrustum=true;
+        } else {
+            this.useClipFrustum=false;
+        }
+    }
+    /** Returns the optional Mv-premultiplied clipping {@link Frustum} or null if unused. */
+    public final Frustum getClipFrustum() { return useClipFrustum ? this.clipFrustum : null; }
 
     /**
      *
-- 
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