Add clipbox management in flat_shader

Polyhedron/demo/Polyhedron/resources/shader_flat.f

@@ -5,6 +5,7 @@ in GS_OUT
   vec4 fP;
   flat vec3 normal;
   flat vec4 color;
+  float dist[6];
 } fs_in;
 
 uniform bool is_two_side;
@@ -13,11 +14,20 @@ uniform vec4 light_diff;
 uniform vec4 light_spec;
 uniform vec4 light_amb;
 uniform float spec_power ;
+uniform bool is_clipbox_on;
 
 out vec4 out_color;
 
 void main(void)
 {
+  if(is_clipbox_on)
+    if(fs_in.dist[0]>0 ||
+       fs_in.dist[1]>0 ||
+       fs_in.dist[2]>0 ||
+       fs_in.dist[3]>0 ||
+       fs_in.dist[4]>0 ||
+       fs_in.dist[5]>0)
+      discard;
   vec3 L = light_pos.xyz - fs_in.fP.xyz;
   vec3 V = -fs_in.fP.xyz;
 

Polyhedron/demo/Polyhedron/resources/shader_flat.g

@@ -8,6 +8,7 @@ in VS_OUT
   vec4 fP;
   vec3 normal;
   vec4 out_color;
+  float dist[6];
 } gs_in[3];
 
 out GS_OUT
@@ -15,6 +16,7 @@ out GS_OUT
   vec4 fP;
   flat vec3 normal;
   flat vec4 color;
+  float dist[6];
 } gs_out;
 
 uniform mat4 mv_matrix;
@@ -24,11 +26,14 @@ void main(void)
   gl_Position = gl_in[0].gl_Position;
   gs_out.fP = gs_in[0].fP;
 
+for(int i=0; i< 6; ++i)
+  gs_out.dist[i] = gs_in[0].dist[i];
   EmitVertex();
 
   gl_Position = gl_in[1].gl_Position;
   gs_out.fP = gs_in[1].fP;
-
+  for(int i=0; i< 6; ++i)
+    gs_out.dist[i] = gs_in[1].dist[i];
 EmitVertex();
 
   gl_Position = gl_in[2].gl_Position;
@@ -45,6 +50,9 @@ EmitVertex();
   gs_out.normal = mat3(mv_matrix)* normal;
   gs_out.color = gs_in[2].out_color;
 
+  for(int i=0; i< 6; ++i)
+    gs_out.dist[i] = gs_in[2].dist[i];
+
   EmitVertex();
 
   EndPrimitive();

Polyhedron/demo/Polyhedron/resources/shader_flat.v

@@ -3,19 +3,41 @@
 in vec4 vertex;
 in vec3 normals;
 in vec4 colors;
-
 out VS_OUT
 {
   vec4 fP;
   vec3 normal;
   vec4 out_color;
+  float dist[6];
 }vs_out;
 
 uniform mat4 mvp_matrix;
 uniform mat4 mv_matrix;
+uniform bool is_clipbox_on;
+uniform highp mat4x4 clipbox1;
+uniform highp mat4x4 clipbox2;
+
+void compute_distances(void)
+{
+  for(int i=0; i<3; ++i)
+  {
+    vs_out.dist[i]=
+    clipbox1[i][0]*vertex.x+
+    clipbox1[i][1]*vertex.y+
+    clipbox1[i][2]*vertex.z +
+    clipbox1[i][3];
+    vs_out.dist[i+3]=
+    clipbox2[i][0]*vertex.x+
+    clipbox2[i][1]*vertex.y+
+    clipbox2[i][2]*vertex.z +
+    clipbox2[i][3];
+  }
+}
 
 void main(void)
 {
+  if(is_clipbox_on)
+    compute_distances();
    vs_out.out_color=colors;
    vs_out.fP = mv_matrix * vertex;
    vs_out.normal = normals;