//  Copyright (C) 2021, Christoph Peters, Karlsruhe Institute of Technology
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program.  If not, see <https://www.gnu.org/licenses/>.


/*! Returns the intersection of the line connecting the given two points with 
	the plane z == 0.0f.*/
vec3 iz0(vec3 lhs, vec3 rhs) {
	float lerp_factor = lhs.z / (lhs.z - rhs.z);
	// Equivalent to the following but I have trust issues regarding the
	// stability of mix()
	// return vec3(mix(lhs.xy, rhs.xy, lerp_factor), 0.0f);
	return vec3(fma(vec2(lerp_factor), rhs.xy, fma(-vec2(lerp_factor), lhs.xy, lhs.xy)), 0.0f);
}


/*! This function clips the given convex polygon with vertices in v to the
	upper hemisphere (i.e. the half-space with non-negative z-coordinate).
	The vertex count after clipping is returned. It is either zero or between
	three and vertex_count + 1. If it is less than MAX_POLYGON_VERTEX_COUNT,
	the first entry of v is repeated at the returned vertex count for the
	output. vertex_count must be at least
	MIN_POLYGON_VERTEX_COUNT_BEFORE_CLIPPING.*/
uint clip_polygon(uint vertex_count, inout vec3 v[MAX_POLYGON_VERTEX_COUNT]) {
	// The vertex count after clipping
	uint vc;
	// Encode the whole configuration into a single integer
	uint bit_mask = vertex_count;
	[[unroll]]
	for (uint i = 0; i != MAX_POLYGON_VERTEX_COUNT - 1; ++i)
		bit_mask |= (v[i].z > 0.0f && (i < MIN_POLYGON_VERTEX_COUNT_BEFORE_CLIPPING || i < vertex_count)) ? (1 << (i + 3)) : 0;
	// This code has been generated automatically to handle all possible cases
	// with a single conditional jump and no unnecessary instructions
	switch (bit_mask) {
	// AUTOGENERATED PART BEGIN
#if MIN_POLYGON_VERTEX_COUNT_BEFORE_CLIPPING <= 3 && MAX_POLYGON_VERTEX_COUNT >= 4
	case    3:   vc = 0;   break;
	case   59:   vc = 3;   v[3] = v[0];   break;
	case   11:   vc = 3;   v[1] = iz0(v[0], v[1]);   v[2] = iz0(v[2], v[0]);   v[3] = v[0];   break;
	case   19:   vc = 3;   v[0] = iz0(v[0], v[1]);   v[2] = iz0(v[1], v[2]);   v[3] = v[0];   break;
	case   35:   vc = 3;   v[0] = iz0(v[2], v[0]);   v[1] = iz0(v[1], v[2]);   v[3] = v[0];   break;
#endif
#if MIN_POLYGON_VERTEX_COUNT_BEFORE_CLIPPING <= 3 && MAX_POLYGON_VERTEX_COUNT == 4
	case   27:   vc = 4;   v[3] = iz0(v[2], v[0]);   v[2] = iz0(v[1], v[2]);   break;
	case   51:   vc = 4;   v[3] = iz0(v[2], v[0]);   v[0] = iz0(v[0], v[1]);   break;
	case   43:   vc = 4;   v[3] = v[2];   v[2] = iz0(v[1], v[2]);   v[1] = iz0(v[0], v[1]);   break;
#elif MIN_POLYGON_VERTEX_COUNT_BEFORE_CLIPPING <= 3 && MAX_POLYGON_VERTEX_COUNT > 4
	case   27:   vc = 4;   v[3] = iz0(v[2], v[0]);   v[2] = iz0(v[1], v[2]);   v[4] = v[0];   break;
	case   51:   vc = 4;   v[3] = iz0(v[2], v[0]);   v[0] = iz0(v[0], v[1]);   v[4] = v[0];   break;
	case   43:   vc = 4;   v[3] = v[2];   v[2] = iz0(v[1], v[2]);   v[1] = iz0(v[0], v[1]);   v[4] = v[0];   break;
#endif
#if MIN_POLYGON_VERTEX_COUNT_BEFORE_CLIPPING <= 4 && MAX_POLYGON_VERTEX_COUNT >= 5
	case    4:   vc = 0;   break;
	case  124:   vc = 4;   v[4] = v[0];   break;
	case   12:   vc = 3;   v[1] = iz0(v[0], v[1]);   v[2] = iz0(v[3], v[0]);   v[3] = v[0];   break;
	case   20:   vc = 3;   v[0] = iz0(v[0], v[1]);   v[2] = iz0(v[1], v[2]);   v[3] = v[0];   break;
	case   36:   vc = 3;   v[0] = iz0(v[2], v[3]);   v[1] = iz0(v[1], v[2]);   v[3] = v[0];   break;
	case   68:   vc = 3;   v[1] = iz0(v[3], v[0]);   v[0] = v[3];   v[2] = iz0(v[2], v[3]);   break;
	case   28:   vc = 4;   v[2] = iz0(v[1], v[2]);   v[3] = iz0(v[3], v[0]);   v[4] = v[0];   break;
	case   52:   vc = 4;   v[0] = iz0(v[0], v[1]);   v[3] = iz0(v[2], v[3]);   v[4] = v[0];   break;
	case  100:   vc = 4;   v[0] = iz0(v[3], v[0]);   v[1] = iz0(v[1], v[2]);   v[4] = v[0];   break;
	case   76:   vc = 4;   v[1] = iz0(v[0], v[1]);   v[2] = iz0(v[2], v[3]);   v[4] = v[0];   break;
#endif
#if MIN_POLYGON_VERTEX_COUNT_BEFORE_CLIPPING <= 4 && MAX_POLYGON_VERTEX_COUNT == 5
	case   60:   vc = 5;   v[4] = iz0(v[3], v[0]);   v[3] = iz0(v[2], v[3]);   break;
	case  116:   vc = 5;   v[4] = iz0(v[3], v[0]);   v[0] = iz0(v[0], v[1]);   break;
	case  108:   vc = 5;   v[4] = v[0];   v[0] = iz0(v[0], v[1]);   v[1] = iz0(v[1], v[2]);   break;
	case   92:   vc = 5;   v[4] = v[3];   v[3] = iz0(v[2], v[3]);   v[2] = iz0(v[1], v[2]);   break;
#elif MIN_POLYGON_VERTEX_COUNT_BEFORE_CLIPPING <= 4 && MAX_POLYGON_VERTEX_COUNT > 5
	case   60:   vc = 5;   v[4] = iz0(v[3], v[0]);   v[3] = iz0(v[2], v[3]);   v[5] = v[0];   break;
	case  116:   vc = 5;   v[4] = iz0(v[3], v[0]);   v[0] = iz0(v[0], v[1]);   v[5] = v[0];   break;
	case  108:   vc = 5;   v[4] = v[0];   v[0] = iz0(v[0], v[1]);   v[1] = iz0(v[1], v[2]);   v[5] = v[0];   break;
	case   92:   vc = 5;   v[4] = v[3];   v[3] = iz0(v[2], v[3]);   v[2] = iz0(v[1], v[2]);   v[5] = v[0];   break;
#endif
#if MIN_POLYGON_VERTEX_COUNT_BEFORE_CLIPPING <= 5 && MAX_POLYGON_VERTEX_COUNT >= 6
	case    5:   vc = 0;   break;
	case  253:   vc = 5;   v[5] = v[0];   break;
	case   13:   vc = 3;   v[1] = iz0(v[0], v[1]);   v[2] = iz0(v[4], v[0]);   v[3] = v[0];   break;
	case   21:   vc = 3;   v[0] = iz0(v[0], v[1]);   v[2] = iz0(v[1], v[2]);   v[3] = v[0];   break;
	case   37:   vc = 3;   v[0] = iz0(v[2], v[3]);   v[1] = iz0(v[1], v[2]);   v[3] = v[0];   break;
	case   69:   vc = 3;   v[0] = v[3];   v[1] = iz0(v[3], v[4]);   v[2] = iz0(v[2], v[3]);   break;
	case  133:   vc = 3;   v[1] = v[4];   v[2] = iz0(v[4], v[0]);   v[0] = iz0(v[3], v[4]);   v[3] = v[0];   break;
	case   29:   vc = 4;   v[2] = iz0(v[1], v[2]);   v[3] = iz0(v[4], v[0]);   v[4] = v[0];   break;
	case   53:   vc = 4;   v[0] = iz0(v[0], v[1]);   v[3] = iz0(v[2], v[3]);   v[4] = v[0];   break;
	case  101:   vc = 4;   v[0] = iz0(v[3], v[4]);   v[1] = iz0(v[1], v[2]);   v[4] = v[0];   break;
	case  197:   vc = 4;   v[1] = iz0(v[4], v[0]);   v[0] = v[4];   v[2] = iz0(v[2], v[3]);   break;
	case  141:   vc = 4;   v[1] = iz0(v[0], v[1]);   v[2] = iz0(v[3], v[4]);   v[3] = v[4];   v[4] = v[0];   break;
	case   61:   vc = 5;   v[3] = iz0(v[2], v[3]);   v[4] = iz0(v[4], v[0]);   v[5] = v[0];   break;
	case  117:   vc = 5;   v[0] = iz0(v[0], v[1]);   v[4] = iz0(v[3], v[4]);   v[5] = v[0];   break;
	case  229:   vc = 5;   v[0] = iz0(v[4], v[0]);   v[1] = iz0(v[1], v[2]);   v[5] = v[0];   break;
	case  205:   vc = 5;   v[1] = iz0(v[0], v[1]);   v[2] = iz0(v[2], v[3]);   v[5] = v[0];   break;
	case  157:   vc = 5;   v[2] = iz0(v[1], v[2]);   v[3] = iz0(v[3], v[4]);   v[5] = v[0];   break;
#endif
#if MIN_POLYGON_VERTEX_COUNT_BEFORE_CLIPPING <= 5 && MAX_POLYGON_VERTEX_COUNT == 6
	case  125:   vc = 6;   v[5] = iz0(v[4], v[0]);   v[4] = iz0(v[3], v[4]);   break;
	case  245:   vc = 6;   v[5] = iz0(v[4], v[0]);   v[0] = iz0(v[0], v[1]);   break;
	case  237:   vc = 6;   v[5] = v[0];   v[0] = iz0(v[0], v[1]);   v[1] = iz0(v[1], v[2]);   break;
	case  221:   vc = 6;   v[5] = v[4];   v[4] = v[3];   v[3] = iz0(v[2], v[3]);   v[2] = iz0(v[1], v[2]);   break;
	case  189:   vc = 6;   v[5] = v[4];   v[4] = iz0(v[3], v[4]);   v[3] = iz0(v[2], v[3]);   break;
#elif MIN_POLYGON_VERTEX_COUNT_BEFORE_CLIPPING <= 5 && MAX_POLYGON_VERTEX_COUNT > 6
	case  125:   vc = 6;   v[5] = iz0(v[4], v[0]);   v[4] = iz0(v[3], v[4]);   v[6] = v[0];   break;
	case  245:   vc = 6;   v[5] = iz0(v[4], v[0]);   v[0] = iz0(v[0], v[1]);   v[6] = v[0];   break;
	case  237:   vc = 6;   v[5] = v[0];   v[0] = iz0(v[0], v[1]);   v[1] = iz0(v[1], v[2]);   v[6] = v[0];   break;
	case  221:   vc = 6;   v[5] = v[4];   v[4] = v[3];   v[3] = iz0(v[2], v[3]);   v[2] = iz0(v[1], v[2]);   v[6] = v[0];   break;
	case  189:   vc = 6;   v[5] = v[4];   v[4] = iz0(v[3], v[4]);   v[3] = iz0(v[2], v[3]);   v[6] = v[0];   break;
#endif
#if MIN_POLYGON_VERTEX_COUNT_BEFORE_CLIPPING <= 6 && MAX_POLYGON_VERTEX_COUNT >= 7
	case    6:   vc = 0;   break;
	case  510:   vc = 6;   v[6] = v[0];   break;
	case   14:   vc = 3;   v[1] = iz0(v[0], v[1]);   v[2] = iz0(v[5], v[0]);   v[3] = v[0];   break;
	case   22:   vc = 3;   v[0] = iz0(v[0], v[1]);   v[2] = iz0(v[1], v[2]);   v[3] = v[0];   break;
	case   38:   vc = 3;   v[0] = iz0(v[2], v[3]);   v[1] = iz0(v[1], v[2]);   v[3] = v[0];   break;
	case   70:   vc = 3;   v[0] = v[3];   v[1] = iz0(v[3], v[4]);   v[2] = iz0(v[2], v[3]);   break;
	case  134:   vc = 3;   v[0] = iz0(v[3], v[4]);   v[1] = v[4];   v[2] = iz0(v[4], v[5]);   v[3] = v[0];   break;
	case  262:   vc = 3;   v[1] = v[5];   v[2] = iz0(v[5], v[0]);   v[0] = iz0(v[4], v[5]);   v[3] = v[0];   break;
	case   30:   vc = 4;   v[2] = iz0(v[1], v[2]);   v[3] = iz0(v[5], v[0]);   v[4] = v[0];   break;
	case   54:   vc = 4;   v[0] = iz0(v[0], v[1]);   v[3] = iz0(v[2], v[3]);   v[4] = v[0];   break;
	case  102:   vc = 4;   v[0] = iz0(v[3], v[4]);   v[1] = iz0(v[1], v[2]);   v[4] = v[0];   break;
	case  198:   vc = 4;   v[0] = v[4];   v[1] = iz0(v[4], v[5]);   v[2] = iz0(v[2], v[3]);   break;
	case  390:   vc = 4;   v[1] = v[5];   v[2] = iz0(v[5], v[0]);   v[0] = v[4];   v[3] = iz0(v[3], v[4]);   break;
	case  270:   vc = 4;   v[1] = iz0(v[0], v[1]);   v[2] = iz0(v[4], v[5]);   v[3] = v[5];   v[4] = v[0];   break;
	case   62:   vc = 5;   v[3] = iz0(v[2], v[3]);   v[4] = iz0(v[5], v[0]);   v[5] = v[0];   break;
	case  118:   vc = 5;   v[0] = iz0(v[0], v[1]);   v[4] = iz0(v[3], v[4]);   v[5] = v[0];   break;
	case  230:   vc = 5;   v[0] = iz0(v[4], v[5]);   v[1] = iz0(v[1], v[2]);   v[5] = v[0];   break;
	case  454:   vc = 5;   v[1] = iz0(v[5], v[0]);   v[0] = v[5];   v[2] = iz0(v[2], v[3]);   break;
	case  398:   vc = 5;   v[2] = iz0(v[0], v[1]);   v[1] = v[0];   v[0] = v[5];   v[3] = iz0(v[3], v[4]);   break;
	case  286:   vc = 5;   v[2] = iz0(v[1], v[2]);   v[3] = iz0(v[4], v[5]);   v[4] = v[5];   v[5] = v[0];   break;
	case  126:   vc = 6;   v[4] = iz0(v[3], v[4]);   v[5] = iz0(v[5], v[0]);   v[6] = v[0];   break;
	case  246:   vc = 6;   v[0] = iz0(v[0], v[1]);   v[5] = iz0(v[4], v[5]);   v[6] = v[0];   break;
	case  486:   vc = 6;   v[0] = iz0(v[5], v[0]);   v[1] = iz0(v[1], v[2]);   v[6] = v[0];   break;
	case  462:   vc = 6;   v[1] = iz0(v[0], v[1]);   v[2] = iz0(v[2], v[3]);   v[6] = v[0];   break;
	case  414:   vc = 6;   v[2] = iz0(v[1], v[2]);   v[3] = iz0(v[3], v[4]);   v[6] = v[0];   break;
	case  318:   vc = 6;   v[3] = iz0(v[2], v[3]);   v[4] = iz0(v[4], v[5]);   v[6] = v[0];   break;
#endif
#if MIN_POLYGON_VERTEX_COUNT_BEFORE_CLIPPING <= 6 && MAX_POLYGON_VERTEX_COUNT == 7
	case  254:   vc = 7;   v[6] = iz0(v[5], v[0]);   v[5] = iz0(v[4], v[5]);   break;
	case  502:   vc = 7;   v[6] = iz0(v[5], v[0]);   v[0] = iz0(v[0], v[1]);   break;
	case  494:   vc = 7;   v[6] = v[0];   v[0] = iz0(v[0], v[1]);   v[1] = iz0(v[1], v[2]);   break;
	case  478:   vc = 7;   v[6] = v[0];   v[0] = v[1];   v[1] = iz0(v[1], v[2]);   v[2] = iz0(v[2], v[3]);   break;
	case  446:   vc = 7;   v[6] = v[5];   v[5] = v[4];   v[4] = iz0(v[3], v[4]);   v[3] = iz0(v[2], v[3]);   break;
	case  382:   vc = 7;   v[6] = v[5];   v[5] = iz0(v[4], v[5]);   v[4] = iz0(v[3], v[4]);   break;
#elif MIN_POLYGON_VERTEX_COUNT_BEFORE_CLIPPING <= 6 && MAX_POLYGON_VERTEX_COUNT > 7
	case  254:   vc = 7;   v[6] = iz0(v[5], v[0]);   v[5] = iz0(v[4], v[5]);   v[7] = v[0];   break;
	case  502:   vc = 7;   v[6] = iz0(v[5], v[0]);   v[0] = iz0(v[0], v[1]);   v[7] = v[0];   break;
	case  494:   vc = 7;   v[6] = v[0];   v[0] = iz0(v[0], v[1]);   v[1] = iz0(v[1], v[2]);   v[7] = v[0];   break;
	case  478:   vc = 7;   v[6] = v[0];   v[0] = v[1];   v[1] = iz0(v[1], v[2]);   v[2] = iz0(v[2], v[3]);   v[7] = v[0];   break;
	case  446:   vc = 7;   v[6] = v[5];   v[5] = v[4];   v[4] = iz0(v[3], v[4]);   v[3] = iz0(v[2], v[3]);   v[7] = v[0];   break;
	case  382:   vc = 7;   v[6] = v[5];   v[5] = iz0(v[4], v[5]);   v[4] = iz0(v[3], v[4]);   v[7] = v[0];   break;
#endif
#if MIN_POLYGON_VERTEX_COUNT_BEFORE_CLIPPING <= 7 && MAX_POLYGON_VERTEX_COUNT >= 8
	case    7:   vc = 0;   break;
	case 1023:   vc = 7;   v[7] = v[0];   break;
	case   15:   vc = 3;   v[1] = iz0(v[0], v[1]);   v[2] = iz0(v[6], v[0]);   v[3] = v[0];   break;
	case   23:   vc = 3;   v[0] = iz0(v[0], v[1]);   v[2] = iz0(v[1], v[2]);   v[3] = v[0];   break;
	case   39:   vc = 3;   v[0] = iz0(v[2], v[3]);   v[1] = iz0(v[1], v[2]);   v[3] = v[0];   break;
	case   71:   vc = 3;   v[0] = v[3];   v[1] = iz0(v[3], v[4]);   v[2] = iz0(v[2], v[3]);   break;
	case  135:   vc = 3;   v[0] = iz0(v[3], v[4]);   v[1] = v[4];   v[2] = iz0(v[4], v[5]);   v[3] = v[0];   break;
	case  263:   vc = 3;   v[0] = iz0(v[4], v[5]);   v[1] = v[5];   v[2] = iz0(v[5], v[6]);   v[3] = v[0];   break;
	case  519:   vc = 3;   v[1] = v[6];   v[2] = iz0(v[6], v[0]);   v[0] = iz0(v[5], v[6]);   v[3] = v[0];   break;
	case   31:   vc = 4;   v[2] = iz0(v[1], v[2]);   v[3] = iz0(v[6], v[0]);   v[4] = v[0];   break;
	case   55:   vc = 4;   v[0] = iz0(v[0], v[1]);   v[3] = iz0(v[2], v[3]);   v[4] = v[0];   break;
	case  103:   vc = 4;   v[0] = iz0(v[3], v[4]);   v[1] = iz0(v[1], v[2]);   v[4] = v[0];   break;
	case  199:   vc = 4;   v[0] = v[4];   v[1] = iz0(v[4], v[5]);   v[2] = iz0(v[2], v[3]);   break;
	case  391:   vc = 4;   v[0] = v[4];   v[1] = v[5];   v[2] = iz0(v[5], v[6]);   v[3] = iz0(v[3], v[4]);   break;
	case  775:   vc = 4;   v[1] = v[5];   v[2] = v[6];   v[3] = iz0(v[6], v[0]);   v[0] = iz0(v[4], v[5]);   v[4] = v[0];   break;
	case  527:   vc = 4;   v[1] = iz0(v[0], v[1]);   v[2] = iz0(v[5], v[6]);   v[3] = v[6];   v[4] = v[0];   break;
	case   63:   vc = 5;   v[3] = iz0(v[2], v[3]);   v[4] = iz0(v[6], v[0]);   v[5] = v[0];   break;
	case  119:   vc = 5;   v[0] = iz0(v[0], v[1]);   v[4] = iz0(v[3], v[4]);   v[5] = v[0];   break;
	case  231:   vc = 5;   v[0] = iz0(v[4], v[5]);   v[1] = iz0(v[1], v[2]);   v[5] = v[0];   break;
	case  455:   vc = 5;   v[0] = v[5];   v[1] = iz0(v[5], v[6]);   v[2] = iz0(v[2], v[3]);   break;
	case  903:   vc = 5;   v[1] = v[6];   v[2] = iz0(v[6], v[0]);   v[0] = v[5];   v[3] = iz0(v[3], v[4]);   break;
	case  783:   vc = 5;   v[1] = iz0(v[0], v[1]);   v[2] = iz0(v[4], v[5]);   v[3] = v[5];   v[4] = v[6];   v[5] = v[0];   break;
	case  543:   vc = 5;   v[2] = iz0(v[1], v[2]);   v[3] = iz0(v[5], v[6]);   v[4] = v[6];   v[5] = v[0];   break;
	case  127:   vc = 6;   v[4] = iz0(v[3], v[4]);   v[5] = iz0(v[6], v[0]);   v[6] = v[0];   break;
	case  247:   vc = 6;   v[0] = iz0(v[0], v[1]);   v[5] = iz0(v[4], v[5]);   v[6] = v[0];   break;
	case  487:   vc = 6;   v[0] = iz0(v[5], v[6]);   v[1] = iz0(v[1], v[2]);   v[6] = v[0];   break;
	case  967:   vc = 6;   v[1] = iz0(v[6], v[0]);   v[0] = v[6];   v[2] = iz0(v[2], v[3]);   break;
	case  911:   vc = 6;   v[2] = iz0(v[0], v[1]);   v[1] = v[0];   v[0] = v[6];   v[3] = iz0(v[3], v[4]);   break;
	case  799:   vc = 6;   v[2] = iz0(v[1], v[2]);   v[3] = iz0(v[4], v[5]);   v[4] = v[5];   v[5] = v[6];   v[6] = v[0];   break;
	case  575:   vc = 6;   v[3] = iz0(v[2], v[3]);   v[4] = iz0(v[5], v[6]);   v[5] = v[6];   v[6] = v[0];   break;
	case  255:   vc = 7;   v[5] = iz0(v[4], v[5]);   v[6] = iz0(v[6], v[0]);   v[7] = v[0];   break;
	case  503:   vc = 7;   v[0] = iz0(v[0], v[1]);   v[6] = iz0(v[5], v[6]);   v[7] = v[0];   break;
	case  999:   vc = 7;   v[0] = iz0(v[6], v[0]);   v[1] = iz0(v[1], v[2]);   v[7] = v[0];   break;
	case  975:   vc = 7;   v[1] = iz0(v[0], v[1]);   v[2] = iz0(v[2], v[3]);   v[7] = v[0];   break;
	case  927:   vc = 7;   v[2] = iz0(v[1], v[2]);   v[3] = iz0(v[3], v[4]);   v[7] = v[0];   break;
	case  831:   vc = 7;   v[3] = iz0(v[2], v[3]);   v[4] = iz0(v[4], v[5]);   v[7] = v[0];   break;
	case  639:   vc = 7;   v[4] = iz0(v[3], v[4]);   v[5] = iz0(v[5], v[6]);   v[7] = v[0];   break;
#endif
#if MIN_POLYGON_VERTEX_COUNT_BEFORE_CLIPPING <= 7 && MAX_POLYGON_VERTEX_COUNT == 8
	case  511:   vc = 8;   v[7] = iz0(v[6], v[0]);   v[6] = iz0(v[5], v[6]);   break;
	case 1015:   vc = 8;   v[7] = iz0(v[6], v[0]);   v[0] = iz0(v[0], v[1]);   break;
	case 1007:   vc = 8;   v[7] = v[0];   v[0] = iz0(v[0], v[1]);   v[1] = iz0(v[1], v[2]);   break;
	case  991:   vc = 8;   v[7] = v[0];   v[0] = v[1];   v[1] = iz0(v[1], v[2]);   v[2] = iz0(v[2], v[3]);   break;
	case  959:   vc = 8;   v[7] = v[6];   v[6] = v[5];   v[5] = v[4];   v[4] = iz0(v[3], v[4]);   v[3] = iz0(v[2], v[3]);   break;
	case  895:   vc = 8;   v[7] = v[6];   v[6] = v[5];   v[5] = iz0(v[4], v[5]);   v[4] = iz0(v[3], v[4]);   break;
	case  767:   vc = 8;   v[7] = v[6];   v[6] = iz0(v[5], v[6]);   v[5] = iz0(v[4], v[5]);   break;
#elif MIN_POLYGON_VERTEX_COUNT_BEFORE_CLIPPING <= 7 && MAX_POLYGON_VERTEX_COUNT > 8
	case  511:   vc = 8;   v[7] = iz0(v[6], v[0]);   v[6] = iz0(v[5], v[6]);   v[8] = v[0];   break;
	case 1015:   vc = 8;   v[7] = iz0(v[6], v[0]);   v[0] = iz0(v[0], v[1]);   v[8] = v[0];   break;
	case 1007:   vc = 8;   v[7] = v[0];   v[0] = iz0(v[0], v[1]);   v[1] = iz0(v[1], v[2]);   v[8] = v[0];   break;
	case  991:   vc = 8;   v[7] = v[0];   v[0] = v[1];   v[1] = iz0(v[1], v[2]);   v[2] = iz0(v[2], v[3]);   v[8] = v[0];   break;
	case  959:   vc = 8;   v[7] = v[6];   v[6] = v[5];   v[5] = v[4];   v[4] = iz0(v[3], v[4]);   v[3] = iz0(v[2], v[3]);   v[8] = v[0];   break;
	case  895:   vc = 8;   v[7] = v[6];   v[6] = v[5];   v[5] = iz0(v[4], v[5]);   v[4] = iz0(v[3], v[4]);   v[8] = v[0];   break;
	case  767:   vc = 8;   v[7] = v[6];   v[6] = iz0(v[5], v[6]);   v[5] = iz0(v[4], v[5]);   v[8] = v[0];   break;
#endif
	// AUTOGENERATED PART END
	default:
		// This should never happen. Just pretend the polygon is below the
		// horizon.
		vc = 0;
		break;
	};
	return vc;
}