PR for sphere_intersection branch

plugins/mmstd_moldyn/Shaders/sphere/vertex_spheretouchplane.glsl

@@ -22,6 +22,7 @@
     vec3 testPos;
     vec4 projPos;
 
+#if 0
     // projected camera vector
     vec3 c2 = vec3(dot(camPos.xyz, camRight), dot(camPos.xyz, camUp), dot(camPos.xyz, camIn));
 
@@ -77,3 +78,53 @@
     testPos = objPos.xyz - camIn * rad;
     projPos = MVP * vec4(testPos, 1.0);
     projPos /= projPos.w;
+#else
+
+    vec3 base_vec = (-camPos.xyz);
+    float bv = length(base_vec);
+
+    //vec3 cc = vec3(dot(base_vec, camRight), dot(base_vec, camUp), dot(base_vec, camIn));
+
+    //vec3 hv = normalize(-cc.z*camRight+cc.x*camIn);
+    //vec3 uv = normalize(cross(hv, base_vec));
+
+    vec3 in_v = normalize(base_vec);
+    vec3 up = normalize(cross(in_v, camRight));
+    vec3 right = normalize(cross(in_v, up));
+    up = normalize(cross(in_v, right));
+
+    float pe = squarRad/bv;
+    float h2 = squarRad-pe*pe;
+    float ha = sqrt(h2);
+    //float qu = bv-pe;
+    //float x = ha/qu*(qu-rad+pe);
+
+    vec3 plane_base = objPos.xyz - in_v*pe;
+    vec3 corner_0 = plane_base-right*ha-up*ha;
+    vec3 corner_1 = plane_base+right*ha-up*ha;
+    vec3 corner_2 = plane_base+right*ha+up*ha;
+    vec3 corner_3 = plane_base-right*ha+up*ha;
+
+    projPos=MVP*vec4(corner_0,1.0);
+    projPos/=projPos.w;
+    mins = projPos.xy;
+    maxs = projPos.xy;
+
+    projPos=MVP*vec4(corner_1,1.0);
+    projPos/=projPos.w;
+    mins = min(mins, projPos.xy);
+    maxs = max(maxs, projPos.xy);
+
+    projPos=MVP*vec4(corner_2,1.0);
+    projPos/=projPos.w;
+    mins = min(mins, projPos.xy);
+    maxs = max(maxs, projPos.xy);
+
+    projPos=MVP*vec4(corner_3,1.0);
+    projPos/=projPos.w;
+    mins = min(mins, projPos.xy);
+    maxs = max(maxs, projPos.xy);
+
+    projPos=MVP*vec4(objPos.xyz - camIn*rad,1.0);
+    projPos/=projPos.w;
+#endif