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

1 files changed, 20 insertions, 2 deletions

diff --git a/src/jogl/classes/jogamp/graph/curve/opengl/shader/functions.glsl b/src/jogl/classes/jogamp/graph/curve/opengl/shader/functions.glsl
index 41e65178e..3b36b021a 100644
--- a/src/jogl/classes/jogamp/graph/curve/opengl/shader/functions.glsl
+++ b/src/jogl/classes/jogamp/graph/curve/opengl/shader/functions.glsl
@@ -75,12 +75,30 @@ vec4 clip_coord(vec4 col_in, vec4 col_ex, vec3 coord, vec3 low, vec3 high) {
  * </p>
  */
 float is_inside(vec2 coord, vec2 low, vec2 high) {
-    return v_mul( step(low, coord) ) * ( 1 - v_or( step(high+EPSILON, coord) ) );    
+    return v_mul( step(low-EPSILON, coord) ) * ( 1 - v_or( step(high+EPSILON, coord) ) );    
 }
 /** Branch-less clipping test using vec3 coordinates and low/high clipping. */
 float is_inside(vec3 coord, vec3 low, vec3 high) {
-    return v_mul( step(low, coord) ) * ( 1 - v_or( step(high+EPSILON, coord) ) );    
+    return v_mul( step(low-EPSILON, coord) ) * ( 1 - v_or( step(high+EPSILON, coord) ) );
 }
 
+/** Return distance of plane {n, d} to given point p. */
+float planeDistance(vec3 n, float d, vec3 p) {
+    return dot(n, p) + d;
+}
+
+#ifdef USE_FRUSTUM_CLIPPING
+
+bool isOutsideMvFrustum(vec3 p) { 
+    return planeDistance(gcu_ClipFrustum[0].xyz, gcu_ClipFrustum[0].w, p) < 0 ||
+           planeDistance(gcu_ClipFrustum[1].xyz, gcu_ClipFrustum[1].w, p) < 0 ||
+           planeDistance(gcu_ClipFrustum[2].xyz, gcu_ClipFrustum[2].w, p) < 0 ||
+           planeDistance(gcu_ClipFrustum[3].xyz, gcu_ClipFrustum[3].w, p) < 0 ||
+           planeDistance(gcu_ClipFrustum[4].xyz, gcu_ClipFrustum[4].w, p) < 0 ||
+           planeDistance(gcu_ClipFrustum[5].xyz, gcu_ClipFrustum[5].w, p) < 0;    
+}
+
+#endif // USE_FRUSTUM_CLIPPING
+
 #endif // functions_glsl