
/* Copyright (c) Mark J. Kilgard, 1994. */

/**
 * (c) Copyright 1993, Silicon Graphics, Inc.
 * ALL RIGHTS RESERVED 
 * Permission to use, copy, modify, and distribute this software for 
 * any purpose and without fee is hereby granted, provided that the above
 * copyright notice appear in all copies and that both the copyright notice
 * and this permission notice appear in supporting documentation, and that 
 * the name of Silicon Graphics, Inc. not be used in advertising
 * or publicity pertaining to distribution of the software without specific,
 * written prior permission. 
 *
 * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
 * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
 * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
 * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
 * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
 * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
 * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
 * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
 * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
 * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
 * 
 * US Government Users Restricted Rights 
 * Use, duplication, or disclosure by the Government is subject to
 * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
 * (c)(1)(ii) of the Rights in Technical Data and Computer Software
 * clause at DFARS 252.227-7013 and/or in similar or successor
 * clauses in the FAR or the DOD or NASA FAR Supplement.
 * Unpublished-- rights reserved under the copyright laws of the
 * United States.  Contractor/manufacturer is Silicon Graphics,
 * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
 *
 * OpenGL(TM) is a trademark of Silicon Graphics, Inc.
 */

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <time.h>
#include <GL/glut.h>

#define MAXOBJS 10000
#define MAXSELECT 100
#define MAXFEED 300
#define	SOLID 1
#define	LINE 2
#define	POINT 3

GLint windW = 300, windH = 300;

GLuint selectBuf[MAXSELECT];
GLfloat feedBuf[MAXFEED];
GLint vp[4];
float zRotation = 90.0;
float zoom = 1.0;
GLint objectCount;
GLint numObjects;
struct object {
  float v1[2];
  float v2[2];
  float v3[2];
  float color[3];
} objects[MAXOBJS];
GLenum linePoly = GL_FALSE;

static void
InitObjects(GLint num)
{
  GLint i;
  float x, y;

  if (num > MAXOBJS) {
    num = MAXOBJS;
  }
  if (num < 1) {
    num = 1;
  }
  objectCount = num;

  srand((unsigned int) time(NULL));
  for (i = 0; i < num; i++) {
    x = (rand() % 300) - 150;
    y = (rand() % 300) - 150;

    objects[i].v1[0] = x + (rand() % 50) - 25;
    objects[i].v2[0] = x + (rand() % 50) - 25;
    objects[i].v3[0] = x + (rand() % 50) - 25;
    objects[i].v1[1] = y + (rand() % 50) - 25;
    objects[i].v2[1] = y + (rand() % 50) - 25;
    objects[i].v3[1] = y + (rand() % 50) - 25;
    objects[i].color[0] = ((rand() % 100) + 50) / 150.0;
    objects[i].color[1] = ((rand() % 100) + 50) / 150.0;
    objects[i].color[2] = ((rand() % 100) + 50) / 150.0;
  }
}

static void
Init(void)
{
  numObjects = 10;
  InitObjects(numObjects);
}

static void
Reshape(int width, int height)
{
  windW = width;
  windH = height;
  glViewport(0, 0, windW, windH);
  glGetIntegerv(GL_VIEWPORT, vp);
}

static void
Render(GLenum mode)
{
  GLint i;

  for (i = 0; i < objectCount; i++) {
    if (mode == GL_SELECT) {
      glLoadName(i);
    }
    glColor3fv(objects[i].color);
    glBegin(GL_POLYGON);
    glVertex2fv(objects[i].v1);
    glVertex2fv(objects[i].v2);
    glVertex2fv(objects[i].v3);
    glEnd();
  }
}

static GLint
DoSelect(GLint x, GLint y)
{
  GLint hits;

  glSelectBuffer(MAXSELECT, selectBuf);
  glRenderMode(GL_SELECT);
  glInitNames();
  glPushName(~0);

  glPushMatrix();

  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluPickMatrix(x, windH - y, 4, 4, vp);
  gluOrtho2D(-175, 175, -175, 175);
  glMatrixMode(GL_MODELVIEW);

  glClearColor(0.0, 0.0, 0.0, 0.0);
  glClear(GL_COLOR_BUFFER_BIT);

  glScalef(zoom, zoom, zoom);
  glRotatef(zRotation, 0, 0, 1);

  Render(GL_SELECT);

  glPopMatrix();

  hits = glRenderMode(GL_RENDER);
  if (hits <= 0) {
    return -1;
  }
  return selectBuf[(hits - 1) * 4 + 3];
}

static void
RecolorTri(GLint h)
{
  objects[h].color[0] = ((rand() % 100) + 50) / 150.0;
  objects[h].color[1] = ((rand() % 100) + 50) / 150.0;
  objects[h].color[2] = ((rand() % 100) + 50) / 150.0;
}

static void
DeleteTri(GLint h)
{
  objects[h] = objects[objectCount - 1];
  objectCount--;
}

static void
GrowTri(GLint h)
{
  float v[2];
  float *oldV;
  GLint i;

  v[0] = objects[h].v1[0] + objects[h].v2[0] + objects[h].v3[0];
  v[1] = objects[h].v1[1] + objects[h].v2[1] + objects[h].v3[1];
  v[0] /= 3;
  v[1] /= 3;

  for (i = 0; i < 3; i++) {
    switch (i) {
    case 0:
      oldV = objects[h].v1;
      break;
    case 1:
      oldV = objects[h].v2;
      break;
    case 2:
      oldV = objects[h].v3;
      break;
    }
    oldV[0] = 1.5 * (oldV[0] - v[0]) + v[0];
    oldV[1] = 1.5 * (oldV[1] - v[1]) + v[1];
  }
}

static void
Mouse(int button, int state, int mouseX, int mouseY)
{
  GLint hit;

  if (state == GLUT_DOWN) {
    hit = DoSelect((GLint) mouseX, (GLint) mouseY);
    if (hit != -1) {
      if (button == GLUT_LEFT_BUTTON) {
        RecolorTri(hit);
      } else if (button == GLUT_MIDDLE_BUTTON) {
        GrowTri(hit);
      } else if (button == GLUT_RIGHT_BUTTON) {
        DeleteTri(hit);
      }
      glutPostRedisplay();
    }
  }
}

static void
Draw(void)
{
  glPushMatrix();
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluOrtho2D(-175, 175, -175, 175);
  glMatrixMode(GL_MODELVIEW);
  glClearColor(0.0, 0.0, 0.0, 0.0);
  glClear(GL_COLOR_BUFFER_BIT);
  glScalef(zoom, zoom, zoom);
  glRotatef(zRotation, 0, 0, 1);
  Render(GL_RENDER);
  glPopMatrix();
  glutSwapBuffers();
}

static void
DumpFeedbackVert(GLint * i, GLint n)
{
  GLint index;

  index = *i;
  if (index + 7 > n) {
    *i = n;
    printf("  ???\n");
    return;
  }
  printf("  (%g %g %g), color = (%4.2f %4.2f %4.2f)\n",
    feedBuf[index],
    feedBuf[index + 1],
    feedBuf[index + 2],
    feedBuf[index + 3],
    feedBuf[index + 4],
    feedBuf[index + 5]);
  index += 7;
  *i = index;
}

static void
DrawFeedback(GLint n)
{
  GLint i;
  GLint verts;

  printf("Feedback results (%d floats):\n", n);
  for (i = 0; i < n; i++) {
    switch ((GLint) feedBuf[i]) {
    case GL_POLYGON_TOKEN:
      printf("Polygon");
      i++;
      if (i < n) {
        verts = (GLint) feedBuf[i];
        i++;
        printf(": %d vertices", verts);
      } else {
        verts = 0;
      }
      printf("\n");
      while (verts) {
        DumpFeedbackVert(&i, n);
        verts--;
      }
      i--;
      break;
    case GL_LINE_TOKEN:
      printf("Line:\n");
      i++;
      DumpFeedbackVert(&i, n);
      DumpFeedbackVert(&i, n);
      i--;
      break;
    case GL_LINE_RESET_TOKEN:
      printf("Line Reset:\n");
      i++;
      DumpFeedbackVert(&i, n);
      DumpFeedbackVert(&i, n);
      i--;
      break;
    default:
      printf("%9.2f\n", feedBuf[i]);
      break;
    }
  }
  if (i == MAXFEED) {
    printf("...\n");
  }
  printf("\n");
}

static void
DoFeedback(void)
{
  GLint x;

  glFeedbackBuffer(MAXFEED, GL_3D_COLOR, feedBuf);
  (void) glRenderMode(GL_FEEDBACK);

  glPushMatrix();

  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluOrtho2D(-175, 175, -175, 175);
  glMatrixMode(GL_MODELVIEW);

  glClearColor(0.0, 0.0, 0.0, 0.0);
  glClear(GL_COLOR_BUFFER_BIT);

  glScalef(zoom, zoom, zoom);
  glRotatef(zRotation, 0, 0, 1);

  Render(GL_FEEDBACK);

  glPopMatrix();

  x = glRenderMode(GL_RENDER);
  if (x == -1) {
    x = MAXFEED;
  }
  DrawFeedback((GLint) x);
}

/* ARGSUSED1 */
static void
Key(unsigned char key, int x, int y)
{

  switch (key) {
  case 'z':
    zoom /= 0.75;
    glutPostRedisplay();
    break;
  case 'Z':
    zoom *= 0.75;
    glutPostRedisplay();
    break;
  case 'f':
    DoFeedback();
    glutPostRedisplay();
    break;
  case 'l':
    linePoly = !linePoly;
    if (linePoly) {
      glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
    } else {
      glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
    }
    glutPostRedisplay();
    break;
  case 27:
    exit(0);
  }
}

/* ARGSUSED1 */
static void
SpecialKey(int key, int x, int y)
{

  switch (key) {
  case GLUT_KEY_LEFT:
    zRotation += 0.5;
    glutPostRedisplay();
    break;
  case GLUT_KEY_RIGHT:
    zRotation -= 0.5;
    glutPostRedisplay();
    break;
  }
}

int
main(int argc, char **argv)
{
  glutInit(&argc, argv);
  glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
  glutCreateWindow("Select Test");
  Init();
  glutReshapeFunc(Reshape);
  glutKeyboardFunc(Key);
  glutSpecialFunc(SpecialKey);
  glutMouseFunc(Mouse);
  glutDisplayFunc(Draw);
  glutMainLoop();
  return 0;             /* ANSI C requires main to return int. */
}
