1/*
2** License Applicability. Except to the extent portions of this file are
3** made subject to an alternative license as permitted in the SGI Free
4** Software License B, Version 1.1 (the "License"), the contents of this
5** file are subject only to the provisions of the License. You may not use
6** this file except in compliance with the License. You may obtain a copy
7** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
8** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
9**
10** http://oss.sgi.com/projects/FreeB
11**
12** Note that, as provided in the License, the Software is distributed on an
13** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
14** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
15** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
16** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
17**
18** Original Code. The Original Code is: OpenGL Sample Implementation,
19** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
20** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
21** Copyright in any portions created by third parties is as indicated
22** elsewhere herein. All Rights Reserved.
23**
24** Additional Notice Provisions: The application programming interfaces
25** established by SGI in conjunction with the Original Code are The
26** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
27** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
28** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
29** Window System(R) (Version 1.3), released October 19, 1998. This software
30** was created using the OpenGL(R) version 1.2.1 Sample Implementation
31** published by SGI, but has not been independently verified as being
32** compliant with the OpenGL(R) version 1.2.1 Specification.
33**
34*/
35/*
36*/
37
38#include "gluos.h"
39#include <stdlib.h>
40#include <stdio.h>
41#include <GL/gl.h>
42#include "zlassert.h"
43#include "gridWrap.h"
44
45
46/*******************grid structure****************************/
47void gridWrap::print()
48{
49  printf("n_ulines = %i\n", n_ulines);
50  printf("n_vlines = %i\n", n_vlines);
51  printf("u_min=%f, umax=%f, vmin=%f, vmax=%f\n", u_min, u_max, v_min, v_max);
52}
53
54gridWrap::gridWrap(Int nUlines, Real* uvals,
55		   Int nVlines, Real* vvals)
56{
57  assert(nUlines>=2);
58  assert(nVlines>=2);
59
60  is_uniform = 0;
61  n_ulines = nUlines;
62  n_vlines = nVlines;
63  u_min = uvals[0];
64  u_max = uvals[nUlines-1];
65  v_min = vvals[0];
66  v_max = vvals[nVlines-1];
67  u_values = (Real*) malloc(sizeof(Real) * n_ulines);
68  assert(u_values);
69  v_values = (Real*) malloc(sizeof(Real) * n_vlines);
70  assert(v_values);
71
72  Int i;
73  for(i=0; i<n_ulines; i++)
74    u_values[i] = uvals[i];
75  for(i=0; i<n_vlines; i++)
76    v_values[i] = vvals[i];
77}
78
79gridWrap::gridWrap(Int nUlines, Int nVlines,
80		   Real uMin, Real uMax,
81		   Real vMin, Real vMax
82		   )
83{
84  is_uniform = 1;
85  n_ulines = nUlines;
86  n_vlines = nVlines;
87  u_min = uMin;
88  u_max = uMax;
89  v_min = vMin;
90  v_max = vMax;
91  u_values = (Real*) malloc(sizeof(Real) * n_ulines);
92  assert(u_values);
93  v_values = (Real*) malloc(sizeof(Real) * n_vlines);
94  assert(v_values);
95
96  Int i;
97  assert(nUlines>=2);
98  assert(nVlines>=2);
99  Real du = (uMax-uMin)/(nUlines-1);
100  Real dv = (vMax-vMin)/(nVlines-1);
101
102  float tempu=uMin;
103  u_values[0] = tempu;
104  for(i=1; i<nUlines; i++)
105    {
106      tempu += du;
107      u_values[i] = tempu;
108    }
109  u_values[nUlines-1] = uMax;
110
111  float tempv=vMin;
112  v_values[0] = tempv;
113  for(i=1; i<nVlines; i++)
114    {
115      tempv += dv;
116      v_values[i] = tempv;
117    }
118  v_values[nVlines-1] = vMax;
119}
120
121gridWrap::~gridWrap()
122{
123  free(u_values);
124  free(v_values);
125}
126
127void gridWrap::draw()
128{
129  int i,j;
130  glBegin(GL_POINTS);
131  for(i=0; i<n_ulines; i++)
132    for(j=0; j<n_vlines; j++)
133      glVertex2f(get_u_value(i), get_v_value(j));
134  glEnd();
135}
136
137void gridWrap::outputFanWithPoint(Int v, Int uleft, Int uright, Real vert[2], primStream* pStream)
138{
139  Int i;
140  if(uleft >= uright)
141    return; //no triangles to output.
142
143  pStream->begin();
144  pStream->insert(vert);
145
146  assert(vert[1] != v_values[v]); //don't output degenerate triangles
147
148  if(vert[1] > v_values[v]) //vertex is above this grid line: notice the orientation
149    {
150      for(i=uleft; i<=uright; i++)
151	pStream->insert(u_values[i], v_values[v]);
152    }
153  else //vertex is below the grid line
154    {
155      for(i=uright; i>= uleft; i--)
156	pStream->insert(u_values[i], v_values[v]);
157    }
158
159  pStream->end(PRIMITIVE_STREAM_FAN);
160}
161
162
163
164/*each chain stores a number of consecutive
165 *V-lines within a grid.
166 *There is one grid vertex on each V-line.
167 * The total number of V-lines is:
168 *   nVlines.
169 * with respect to the grid, the index of the first V-line is
170 *   firstVlineIndex.
171 * So with respect to the grid, the index of the ith V-line is
172 *   firstVlineIndex-i.
173 * the grid-index of the uline at the ith vline (recall that each vline has one grid point)
174 * is ulineIndices[i]. The u_value is cached in ulineValues[i], that is,
175 *   ulineValues[i] = grid->get_u_value(ulineIndices[i])
176 */
177gridBoundaryChain::gridBoundaryChain(
178				     gridWrap* gr,
179				     Int first_vline_index,
180				     Int n_vlines,
181				     Int* uline_indices,
182				     Int* inner_indices
183				     )
184: grid(gr), firstVlineIndex(first_vline_index), nVlines(n_vlines)
185{
186  ulineIndices = (Int*) malloc(sizeof(Int) * n_vlines);
187  assert(ulineIndices);
188
189  innerIndices = (Int*) malloc(sizeof(Int) * n_vlines);
190  assert(innerIndices);
191
192  vertices = (Real2*) malloc(sizeof(Real2) * n_vlines);
193  assert(vertices);
194
195
196
197  Int i;
198  for(i=0; i<n_vlines; i++){
199    ulineIndices[i] = uline_indices[i];
200    innerIndices[i] = inner_indices[i];
201  }
202
203  for(i=0; i<n_vlines; i++){
204    vertices[i][0] = gr->get_u_value(ulineIndices[i]);
205    vertices[i][1] = gr->get_v_value(first_vline_index-i);
206  }
207}
208
209void gridBoundaryChain::draw()
210{
211  Int i;
212  glBegin(GL_LINE_STRIP);
213  for(i=0; i<nVlines; i++)
214    {
215      glVertex2fv(vertices[i]);
216    }
217  glEnd();
218}
219
220void gridBoundaryChain::drawInner()
221{
222  Int i;
223  for(i=1; i<nVlines; i++)
224    {
225      glBegin(GL_LINE_STRIP);
226      glVertex2f(grid->get_u_value(innerIndices[i]), get_v_value(i-1) );
227      glVertex2f(grid->get_u_value(innerIndices[i]), get_v_value(i) );
228      glEnd();
229    }
230}
231
232Int gridBoundaryChain::lookfor(Real v, Int i1, Int i2)
233{
234  Int mid;
235  while(i1 < i2-1)
236    {
237      mid = (i1+i2)/2;
238      if(v > vertices[mid][1])
239	{
240	  i2 = mid;
241	}
242      else
243	i1 = mid;
244    }
245  return i1;
246}
247
248/*output the fan of the right end between grid line i-1 and grid line i*/
249void gridBoundaryChain::rightEndFan(Int i, primStream* pStream)
250{
251  Int j;
252  if(getUlineIndex(i) > getUlineIndex(i-1))
253    {
254      pStream->begin();
255      pStream->insert(get_vertex(i-1));
256      for(j=getUlineIndex(i-1); j<= getUlineIndex(i); j++)
257	pStream->insert(grid->get_u_value(j), get_v_value(i));
258      pStream->end(PRIMITIVE_STREAM_FAN);
259    }
260  else if(getUlineIndex(i) < getUlineIndex(i-1))
261    {
262      pStream->begin();
263      pStream->insert(get_vertex(i));
264      for(j=getUlineIndex(i-1); j>= getUlineIndex(i); j--)
265	pStream->insert(grid->get_u_value(j), get_v_value(i-1));
266      pStream->end(PRIMITIVE_STREAM_FAN);
267    }
268  //otherside, the two are equal, so there is no fan to output
269}
270
271
272/*output the fan of the left end between grid line i-1 and grid line i*/
273void gridBoundaryChain::leftEndFan(Int i, primStream* pStream)
274{
275  Int j;
276  if(getUlineIndex(i) < getUlineIndex(i-1))
277    {
278      pStream->begin();
279      pStream->insert(get_vertex(i-1));
280      for(j=getUlineIndex(i); j<= getUlineIndex(i-1); j++)
281	pStream->insert(grid->get_u_value(j), get_v_value(i));
282      pStream->end(PRIMITIVE_STREAM_FAN);
283    }
284  else if(getUlineIndex(i) > getUlineIndex(i-1))
285    {
286      pStream->begin();
287      pStream->insert(get_vertex(i));
288      for(j=getUlineIndex(i); j>= getUlineIndex(i-1); j--)
289	pStream->insert(grid->get_u_value(j), get_v_value(i-1));
290      pStream->end(PRIMITIVE_STREAM_FAN);
291    }
292  /*otherwisem, the two are equal, so there is no fan to outout*/
293}
294