1 files changed, 399 insertions, 0 deletions
diff --git a/tests/glfw/wave.c b/tests/glfw/wave.c
new file mode 100644
index 00000000..67f516cc
--- /dev/null
+++ b/tests/glfw/wave.c
@@ -0,0 +1,399 @@
+/*****************************************************************************
+ * Wave Simulation in OpenGL
+ * (C) 2002 Jakob Thomsen
+ * http://home.in.tum.de/~thomsen
+ * Modified for GLFW by Sylvain Hellegouarch - sh@programmationworld.com
+ * Modified for variable frame rate by Marcus Geelnard
+ * 2003-Jan-31: Minor cleanups and speedups / MG
+ *****************************************************************************/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <GL/glfw.h>
+
+#ifndef M_PI
+ #define M_PI 3.1415926535897932384626433832795
+#endif
+
+/* Maximum delta T to allow for differential calculations */
+#define MAX_DELTA_T 0.01
+
+/* Animation speed (10.0 looks good) */
+#define ANIMATION_SPEED 10.0
+
+
+GLfloat alpha = 210.0f, beta = -70.0f;
+GLfloat zoom = 2.0f;
+
+int running = 1;
+
+struct Vertex
+{
+  GLfloat x,y,z;
+  GLfloat r,g,b;
+};
+
+#define GRIDW 50
+#define GRIDH 50
+#define VERTEXNUM (GRIDW*GRIDH)
+
+#define QUADW (GRIDW-1)
+#define QUADH (GRIDH-1)
+#define QUADNUM (QUADW*QUADH)
+
+GLuint quad[4*QUADNUM];
+struct Vertex vertex[VERTEXNUM];
+
+/* The grid will look like this:
+ *
+ *      3   4   5
+ *      *---*---*
+ *      |   |   |
+ *      | 0 | 1 |
+ *      |   |   |
+ *      *---*---*
+ *      0   1   2
+ */
+
+void initVertices( void )
+{
+  int x,y,p;
+
+  /* place the vertices in a grid */
+  for(y=0;y<GRIDH;y++)
+    for(x=0;x<GRIDW;x++)
+    {
+      p = y*GRIDW + x;
+
+      //vertex[p].x = (-GRIDW/2)+x+sin(2.0*M_PI*(double)y/(double)GRIDH);
+      //vertex[p].y = (-GRIDH/2)+y+cos(2.0*M_PI*(double)x/(double)GRIDW);
+      vertex[p].x = (GLfloat)(x-GRIDW/2)/(GLfloat)(GRIDW/2);
+      vertex[p].y = (GLfloat)(y-GRIDH/2)/(GLfloat)(GRIDH/2);
+      vertex[p].z = 0;//sin(d*M_PI);
+      //vertex[p].r = (GLfloat)x/(GLfloat)GRIDW;
+      //vertex[p].g = (GLfloat)y/(GLfloat)GRIDH;
+      //vertex[p].b = 1.0-((GLfloat)x/(GLfloat)GRIDW+(GLfloat)y/(GLfloat)GRIDH)/2.0;
+      if((x%4<2)^(y%4<2))
+      {
+        vertex[p].r = 0.0;
+      }
+      else
+      {
+        vertex[p].r=1.0;
+      }
+
+      vertex[p].g = (GLfloat)y/(GLfloat)GRIDH;
+      vertex[p].b = 1.f-((GLfloat)x/(GLfloat)GRIDW+(GLfloat)y/(GLfloat)GRIDH)/2.f;
+    }
+
+  for(y=0;y<QUADH;y++)
+    for(x=0;x<QUADW;x++)
+    {
+      p = 4*(y*QUADW + x);
+
+      /* first quad */
+      quad[p+0] = y    *GRIDW+x;    /* some point */
+      quad[p+1] = y    *GRIDW+x+1;  /* neighbor at the right side */
+      quad[p+2] = (y+1)*GRIDW+x+1;  /* upper right neighbor */
+      quad[p+3] = (y+1)*GRIDW+x;    /* upper neighbor */
+    }
+}
+
+double dt;
+double p[GRIDW][GRIDH];
+double vx[GRIDW][GRIDH], vy[GRIDW][GRIDH];
+double ax[GRIDW][GRIDH], ay[GRIDW][GRIDH];
+
+
+
+void initSurface( void )
+{
+  int    x, y;
+  double dx, dy, d;
+
+  for(y = 0; y<GRIDH; y++)
+  {
+    for(x = 0; x<GRIDW; x++)
+    {
+      dx = (double)(x-GRIDW/2);
+      dy = (double)(y-GRIDH/2);
+      d = sqrt( dx*dx + dy*dy );
+      if(d < 0.1 * (double)(GRIDW/2))
+      {
+        d = d * 10.0;
+        p[x][y] = -cos(d * (M_PI / (double)(GRIDW * 4))) * 100.0;
+      }
+      else
+      {
+        p[x][y] = 0.0;
+      }
+      vx[x][y] = 0.0;
+      vy[x][y] = 0.0;
+    }
+  }
+}
+
+
+/* Draw view */
+void draw_screen( void )
+{
+  /* Clear the color and depth buffers. */
+  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+  /* We don't want to modify the projection matrix. */
+  glMatrixMode(GL_MODELVIEW);
+  glLoadIdentity();
+
+  /* Move back. */
+  glTranslatef(0.0, 0.0, -zoom);
+  /* Rotate the view */
+  glRotatef(beta, 1.0, 0.0, 0.0);
+  glRotatef(alpha, 0.0, 0.0, 1.0);
+
+  //glDrawArrays(GL_POINTS,0,VERTEXNUM); /* Points only */
+  glDrawElements(GL_QUADS, 4*QUADNUM, GL_UNSIGNED_INT, quad);
+  //glDrawElements(GL_LINES, QUADNUM, GL_UNSIGNED_INT, quad);
+
+  glfwSwapBuffers();
+}
+
+
+/* Initialize OpenGL */
+void setup_opengl( void )
+{
+  /* Our shading model--Gouraud (smooth). */
+  glShadeModel(GL_SMOOTH);
+
+  /* Culling. */
+  //glCullFace(GL_BACK);
+  //glFrontFace(GL_CCW);
+  //glEnable(GL_CULL_FACE);
+
+  /* Switch on the z-buffer. */
+  glEnable(GL_DEPTH_TEST);
+
+  glEnableClientState(GL_VERTEX_ARRAY);
+  glEnableClientState(GL_COLOR_ARRAY);
+  glVertexPointer(3/*3 components per vertex (x,y,z)*/, GL_FLOAT, sizeof(struct Vertex), vertex);
+  glColorPointer(3/*3 components per vertex (r,g,b)*/, GL_FLOAT, sizeof(struct Vertex), &vertex[0].r);  //Pointer to the first color
+  glPointSize(2.0);
+
+  /* Background color is black. */
+  glClearColor(0, 0, 0, 0);
+}
+
+
+/* Modify the height of each vertex according to the pressure. */
+void adjustGrid( void )
+{
+  int pos;
+  int x, y;
+
+  for(y = 0; y<GRIDH; y++)
+  {
+    for(x = 0; x<GRIDW; x++)
+    {
+      pos = y*GRIDW + x;
+      vertex[pos].z = (float) (p[x][y]*(1.0/50.0));
+    }
+  }
+}
+
+
+/* Calculate wave propagation */
+void calc( void )
+{
+  int    x, y, x2, y2;
+  double time_step = dt * ANIMATION_SPEED;
+
+  /* compute accelerations */
+  for(x = 0; x < GRIDW; x++)
+  {
+    x2 = (x + 1) % GRIDW;
+    for(y = 0; y < GRIDH; y++)
+    {
+      ax[x][y] = p[x][y] - p[x2][y];
+    }
+  }
+
+  for(y = 0; y < GRIDH;y++)
+  {
+    y2 = (y + 1) % GRIDH;
+    for(x = 0; x < GRIDW; x++)
+    {
+      ay[x][y] = p[x][y] - p[x][y2];
+    }
+  }
+
+  /* compute speeds */
+  for(x = 0; x < GRIDW; x++)
+  {
+    for(y = 0; y < GRIDH; y++)
+    {
+      vx[x][y] = vx[x][y] + ax[x][y] * time_step;
+      vy[x][y] = vy[x][y] + ay[x][y] * time_step;
+    }
+  }
+
+  /* compute pressure */
+  for(x = 1; x < GRIDW; x++)
+  {
+    x2 = x - 1;
+    for(y = 1; y < GRIDH; y++)
+    {
+      y2 = y - 1;
+      p[x][y] = p[x][y] + (vx[x2][y] - vx[x][y] + vy[x][y2] - vy[x][y]) * time_step;
+    }
+  }
+}
+
+
+/* Handle key strokes */
+void GLFWCALL handle_key_down(int key, int action)
+{
+  if( action != GLFW_PRESS )
+  {
+    return;
+  }
+
+  switch(key) {
+    case GLFW_KEY_ESC:
+      running = 0;
+      break;
+    case GLFW_KEY_SPACE:
+      initSurface();
+      break;
+    case GLFW_KEY_LEFT:
+      alpha+=5;
+      break;
+    case GLFW_KEY_RIGHT:
+      alpha-=5;
+      break;
+    case GLFW_KEY_UP:
+      beta-=5;
+      break;
+    case GLFW_KEY_DOWN:
+      beta+=5;
+      break;
+    case GLFW_KEY_PAGEUP:
+      if(zoom>1) zoom-=1;
+      break;
+    case GLFW_KEY_PAGEDOWN:
+      zoom+=1;
+      break;
+    default:
+      break;
+  }
+}
+
+
+/* Callback function for window resize events */
+void GLFWCALL handle_resize( int width, int height )
+{
+  float ratio = 1.0f;
+
+  if( height > 0 )
+  {
+      ratio = (float) width / (float) height;
+  }
+
+  /* Setup viewport (Place where the stuff will appear in the main window). */
+  glViewport(0, 0, width, height);
+
+  /*
+   * Change to the projection matrix and set
+   * our viewing volume.
+   */
+  glMatrixMode(GL_PROJECTION);
+  glLoadIdentity();
+  gluPerspective(60.0, ratio, 1.0, 1024.0);
+}
+
+
+/* Program entry point */
+int main(int argc, char* argv[])
+{
+  /* Dimensions of our window. */
+  int width, height;
+  /* Style of our window. */
+  int mode;
+  /* Frame time */
+  double t, t_old, dt_total;
+
+  /* Initialize GLFW */
+  if(glfwInit() == GL_FALSE)
+  {
+    fprintf(stderr, "GLFW initialization failed\n");
+    exit(-1);
+  }
+
+  /* Desired window properties */
+  width  = 640;
+  height = 480;
+  mode   = GLFW_WINDOW;
+
+  /* Open window */
+  if( glfwOpenWindow(width,height,0,0,0,0,16,0,mode) == GL_FALSE )
+  {
+    fprintf(stderr, "Could not open window\n");
+    glfwTerminate();
+    exit(-1);
+  }
+
+  /* Set title */
+  glfwSetWindowTitle( "Wave Simulation" );
+
+  glfwSwapInterval( 1 );
+
+  /* Keyboard handler */
+  glfwSetKeyCallback( handle_key_down );
+  glfwEnable( GLFW_KEY_REPEAT );
+
+  /* Window resize handler */
+  glfwSetWindowSizeCallback( handle_resize );
+
+  /* Initialize OpenGL */
+  setup_opengl();
+
+  /* Initialize simulation */
+  initVertices();
+  initSurface();
+  adjustGrid();
+
+  /* Initialize timer */
+  t_old = glfwGetTime() - 0.01;
+
+  /* Main loop */
+  while(running)
+  {
+    /* Timing */
+    t = glfwGetTime();
+    dt_total = t - t_old;
+    t_old = t;
+
+    /* Safety - iterate if dt_total is too large */
+    while( dt_total > 0.0f )
+    {
+        /* Select iteration time step */
+        dt = dt_total > MAX_DELTA_T ? MAX_DELTA_T : dt_total;
+        dt_total -= dt;
+
+        /* Calculate wave propagation */
+        calc();
+    }
+
+    /* Compute height of each vertex */
+    adjustGrid();
+
+    /* Draw wave grid to OpenGL display */
+    draw_screen();
+
+    /* Still running? */
+    running = running && glfwGetWindowParam( GLFW_OPENED );
+  }
+
+  glfwTerminate();
+
+  return 0;
+}