course/semester2/pprog/assignment1/graphics.c

   1 /**
   2  * @file graphics.c
   3  * @author Sam Moore (20503628) 2012 - adapted from template program provided by UWA
   4  * @purpose Definition of graphics related functions
   5  */
   6
   7 #include "graphics.h" //Function declarations
   8 #include <time.h> // Needed for clock
   9 #include <math.h> // Maths functions (sin, cos)
  10 /**
  11  * Variables
  12  */
  13 double previousTime, eyeTheta, eyePhi, eyeRho;
  14 float look[3];
  15 int windowWidth, windowHeight, upY;
  16
  17 double scale = 1.0;
  18
  19
  20 /**
  21  * Initialise the graphics
  22  */
  23 void Graphics_Init(void)
  24 {
  25
  26         glClearColor(1.0,1.0,1.0,0.0);
  27         glColor3f(0.0f, 0.0f, 0.0f);
  28         glPointSize(POINT_SIZE);
  29         glMatrixMode(GL_PROJECTION);
  30         glLoadIdentity();
  31
  32         /*init lighting */
  33
  34         GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
  35         GLfloat mat_shininess[] = { 50.0 };
  36         GLfloat light_position[] = { 1.0, 1.0, 0.0, 0.0 };
  37         glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
  38         glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
  39         glLightfv(GL_LIGHT0, GL_POSITION, light_position);
  40
  41         glColorMaterial(GL_FRONT,GL_DIFFUSE);                // Set Color Capability
  42
  43         glEnable(GL_LIGHTING);
  44         glEnable(GL_LIGHT0);
  45         glEnable(GL_DEPTH_TEST);
  46
  47         glEnable(GL_COLOR_MATERIAL);                   // Enable color
  48
  49
  50         windowWidth = WIDTH;
  51         windowHeight = HEIGHT;
  52         previousTime = clock();
  53         eyeTheta = 0;
  54         eyePhi = 0.5 * M_PI;
  55         eyeRho = RHO;
  56         upY = 1;
  57         look[0] = 0;
  58         look[1] = 0;
  59         look[2] = 0;
  60         gluPerspective(VIEW_ANGLE, (double)WIDTH/(double)HEIGHT, WORLD_NEAR, WORLD_FAR);
  61 }
  62
  63 /**
  64  * This function redraws the screen after the positions of particles
  65  * have been updated
  66  */
  67 void Graphics_Display(System * s)
  68 {
  69         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  70         glMatrixMode(GL_MODELVIEW);
  71         glLoadIdentity();
  72         gluLookAt(eyeRho * sin(eyePhi) * sin(eyeTheta), eyeRho * cos(eyePhi),
  73                 eyeRho * sin(eyePhi) * cos(eyeTheta),look[0], look[1], look[2], 0, upY, 0);
  74
  75         for (int i = 0; i < s->N; ++i)
  76         {
  77                 Body * b = s->body+i;
  78                 glColor3f(0.0f, b->mass/1e11*100, 0.0f);
  79                 glPushMatrix(); // to save the current matrix
  80                 glTranslated(scale*b->x[0], scale*b->x[1], scale*b->x[2]);
  81                 glutSolidSphere (BALL_SIZE, 10, 10);
  82                 glPopMatrix(); // restore the previous matrix
  83         }
  84         glFlush();
  85 }
  86
  87 /**
  88  * This function is to manipulate with the image
  89  */
  90 void Graphics_Keyboard(unsigned char theKey, int mouseX, int mouseY)
  91 {
  92         if (theKey == 'x' || theKey == 'X')
  93         {
  94                 exit(EXIT_SUCCESS);
  95         }
  96
  97                 if (theKey == 'i' || theKey == 'I') {
  98                         eyePhi -= M_PI / 20;
  99                 if (eyePhi == 0)
 100                                 eyePhi = 2 * M_PI;
 101                 } else if (theKey == 'm' || theKey == 'I') {
 102                         eyePhi += M_PI / 20;
 103                 } else if (theKey == 'j' || theKey == 'J') {
 104                         eyeTheta -= M_PI / 20;
 105                 } else if (theKey == 'k' || theKey == 'K') {
 106                         eyeTheta += M_PI / 20;
 107                 } else if (theKey == ',') {
 108                         eyeRho += 0.5;
 109                 } else if (theKey == '.' || theKey == 'I') {
 110                         eyeRho -= 0.5;
 111                 } else if (theKey == 'w' || theKey == 'W') {
 112                         look[1] += 0.5;
 113                 } else if (theKey == 'z' || theKey == 'Z') {
 114                         look[1] -= 0.5;
 115                 } else if (theKey == 'a' || theKey == 'A') {
 116                         look[0] -= 0.5;
 117                 } else if (theKey == 's' || theKey == 'S') {
 118                         look[0] += 0.5;
 119                 } else if (theKey == '+') {
 120                         scale *= 1.1;
 121                 } else if (theKey == '-') {
 122                         scale *= 0.9;
 123                 }
 124                 if (sin(eyePhi) > 0) upY = 1;
 125                 else upY = 1;
 126 }
 127
 128 /**
 129  * Resize the view window
 130  */
 131 void Graphics_Reshape(int width, int height)
 132 {
 133         double displayRatio = 1.0 * width / height;
 134         windowWidth = width;
 135         windowHeight = height;
 136         glMatrixMode(GL_PROJECTION);
 137         glLoadIdentity();
 138         gluPerspective(VIEW_ANGLE, displayRatio, WORLD_NEAR, WORLD_FAR);
 139         glViewport(0, 0, windowWidth, windowHeight);
 140 }
 141
 142
 143 /**
 144  * This function is called repeatedly by graphics library. You can consider
 145  * it as main loop in the program.
 146  */
 147 void Graphics_Animate(void)
 148 {
 149
 150         System_Compute(&universe); //Compute and update new positions for the time step
 151         Graphics_Display(&universe); // Display needs to be called to redraw the screen
 152 }