Merge branch 'master' of ssh://vo20.nl/git/uva

graphics/.gitignore

 *.o
+ass*.tar.gz

graphics/ass7/intersection.c

@@ -217,8 +217,9 @@ intersect_node(bvh_node *node, intersection_point *ip,
 	}
 	else
 	{
-		// Leaf node, find shortest triangle and check if it is closer than the
-		// current closest intersection
+		// Leaf node, find the shortest triangle in the leaf and check if it is
+		// closer to the origin than the current closest intersection. If so,
+		// make it the new closest intersection.
 		triangle *triangles = leaf_node_triangles(node);
 		intersection_point ip2;
 		
@@ -253,13 +254,6 @@ find_first_intersected_bvh_triangle(intersection_point* ip,
     ip->t = C_INFINITY;
     
     // If the root has no intersection, none of the BVH nodes does
-    // 
-    // Note that this step if mkes the program less efficient when the root's
-    // bounding box has a relatively large surface in the camera screen (has 
-    // lot of ray intersections). This is because every ray intersecting a
-    // triangle is now tested one time more and every non-intersection ray is
-    // tested one time less. So, when raytracing large objects, omitting this
-    // step would be advisable.
     if( !bbox_intersect(&t0, &t1, bvh_root->bbox, ray_origin,
                         ray_direction, 0.0, C_INFINITY) )
     {

graphics/ass7/main.c

 /* Computer Graphics, Assignment, Ray-tracing 2
  *
- * Student name ....
- * Student email ...
- * Collegekaart ....
- * Date ............
- * Comments ........
- *
- *
- * (always fill in these fields before submitting!!)
+ * Student name .... Sander van Veen & Taddeus Kroes
+ * Student email ... sandervv@gmail.com & taddeuskroes@hotmail.com
+ * Collegekaart .... 6167969 & 6054129
+ * Date ............ 07.11.2010
  */
 
 #include <sys/time.h>
@@ -160,7 +156,7 @@ ray_trace(void)
     vec3    forward_vector, right_vector, up_vector;
     int     i, j, k, l;
     vec3    right_step, down_step;
-    float   image_plane_width, image_plane_height, diff[2] = {0.25, 0.75};
+    float   image_plane_width, image_plane_height, pixel_diff[2] = {0.25, 0.75};
     vec3    image_plane_topleft, image_plane_point;
     vec3    ray_direction;
     vec3    color;
@@ -203,26 +199,34 @@ ray_trace(void)
     {
         for (i = 0; i < framebuffer_width; i++)
         {
-        	if( do_antialiasing)
+        	if( do_antialiasing )
         	{
-		    	color.x = color.y = color.z = 0;
+        		// Anti-aliasing is on, shoot 4 rays through each point and use the average
+		    	color.x = color.y = color.z = 0.0;
 		    	
 		    	for( k = 0; k < 2; k++ )
 		    	{
 					for( l = 0; l < 2; l++ )
 					{
-						// Compute corresponding point on image plane
-						image_plane_point = v3_add(image_plane_topleft, v3_multiply(right_step, i+diff[k]));
-						image_plane_point = v3_add(image_plane_point, v3_multiply(down_step, j+diff[l]));
+						// Compute corresponding point corner on image plane
+						image_plane_point = v3_add(
+							image_plane_topleft,
+							v3_multiply(right_step, i+pixel_diff[k])
+						);
+						image_plane_point = v3_add(
+							image_plane_point,
+							v3_multiply(down_step, j+pixel_diff[l])
+						);
 
 						// Compute direction for shooting the ray
 						ray_direction = v3_subtract(image_plane_point, scene_camera_position);
 
-						// Determine ray color
+						// Add ray color for this corner to the current color
 						color = v3_add(color, ray_color(0, scene_camera_position, ray_direction));
 					}
 				}
-			
+				
+				// Divide by 4 to get the average of all corners, this is the point color
 				color = v3_multiply(color, 0.25);
 			}
 			else

graphics/ass8/Makefile

+CC=gcc
+
+WARNING_FLAGS=-Wall -Wextra -Werror-implicit-function-declaration -Wshadow -Wstrict-prototypes -pedantic-errors
+CFLAGS=-g -O2 -std=c99 $(WARNING_FLAGS)
+LDFLAGS=-g -lGL -lglut -lGLU
+
+.c.o:
+	$(CC) -c $(CFLAGS) $<
+
+all: main
+main: main.o volume.o
+	$(CC) $(LDFLAGS) -o main main.o volume.o
+
+clean:
+	rm -f *.o
+	rm -f main
+
+volume.o : volume.h
+main.o   : volume.h main.c
+volume.o : volume.h volume.c

graphics/ass8/framerates.txt

+We did the following measurements with out program.
+
++----------------+-----+-----------------------+---------------------+-------------+
+| dataset        | iso | framerate unoptimized | framerate optimized | improvement |
+|                |     | (points/cubes)        | (points/cubes)      | ratio       |
++----------------+-----+-----------------------+---------------------+-------------+
+| frog.small.vtk | 78  | 80 / 19               | 670 / 235           | 8.4  / 12.4 |
++----------------+-----+-----------------------+---------------------+-------------+
+| knee.vtk       | 60  | 58 / 2                | 362 / 29            | 6.2  / 14.5 |
++----------------+-----+-----------------------+---------------------+-------------+
+| mummy.128.vtk  | 50  | 40 / 5                | 515 / 86            | 12.9 / 17.2 |
++----------------+-----+-----------------------+---------------------+-------------+
+
+We can see that the improvement in performance is very large, especially for
+the cubes. This makes sense, because when not using arrays, all of the cubes
+have to be translated and transformed whereas the points only have to be
+calculated. Still, the optimization certainly also pays off for the points.

graphics/ass8/main.c

+/* Computer Graphics, Assignment, Volume rendering with cubes/points
+ *
+ * Filename ........ main.c
+ * Description ..... Creates OpenGL window and draws the scene.
+ * Date ............ 29.10.2008
+ * Created by ...... Paul Melis
+ *
+ * Student name .... Sander van Veen & Taddeus Kroes
+ * Student email ... sandervv@gmail.com & taddeuskroes@hotmail.com
+ * Collegekaart .... 6167969 & 6054129
+ * Date ............ 07.11.2010
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/time.h>
+#include <GL/glut.h>
+#include <GL/gl.h>
+#include <GL/glu.h>
+#include <math.h>
+
+#include "volume.h"
+#include "v3math.h"
+
+int             display_mode=0;         /* 0 = points, 1 = cubes */
+int             use_arrays=0;
+unsigned char   isovalue=128;
+unsigned char   epsilon=0;
+
+int             window;
+int             mouse_mode=0;
+int             mx, my;
+float           camDistance=100.0;
+float           camRotZ=45.0, camAzimuth=20.0;
+float           saved_camRotZ, saved_camAzimuth, saved_camDistance;
+int             regenerate_arrays=1;
+int             entered_number=0;
+int             display_fps_counter=0;
+int             backface_culling=0;
+
+#define MAX_VERTICES_IN_ARRAY   5000000
+
+int             num_vertices_in_array=0;
+float           vertices[3*MAX_VERTICES_IN_ARRAY];
+float           normals[3*MAX_VERTICES_IN_ARRAY];
+
+void    SetupCamera(void);
+void    DrawVolumeAxes(void);
+void    DrawVolumeUsingCurrentDisplayMode(void);
+
+/* Some definitions and global variables for use in the filled-in functions */
+#define TIMER_FRAMERATE 30
+#define POINT_SIZE 1.0
+
+int timer = TIMER_FRAMERATE + 1;
+struct timeval start, end;
+float x_center = 0.0, y_center = 0.0, z_center = 0.0;
+float normal_x_size = 0.0, normal_y_size = 0.0;
+
+/* Draw the selected iso-value (range) using GL_POINTS */
+
+void DrawVolumeAsPoints(void)
+{
+	int x, y, z;
+	char value;
+	
+	/* Initialize global help variables */
+	if( x_center == 0.0 || y_center == 0.0 || z_center == 0.0 )
+	{
+		x_center = .5 * sizex;
+		y_center = .5 * sizey;
+		z_center = .5 * sizez;
+	}
+	
+	/* Go through all voxels and compare them to the volume dataset. If the
+	 * the value is in the specified range, draw a point at that location. */
+	glBegin(GL_POINTS);
+	
+	for( x = 0; x < nx; x++ )
+		for( y = 0; y < ny; y++ )
+			for( z = 0; z < nz; z++ )
+				if( (value = volume[voxel2idx(x, y, z)]) >= isovalue - epsilon
+				    && value <= isovalue + epsilon )
+					glVertex3f(x + x_center, y + y_center, z + z_center);
+	
+	glEnd();
+}
+
+/* Draw the selected iso-value (range) using glutSolidCube()'s */
+
+void DrawVolumeAsCubes(void)
+{
+	int x, y, z;
+	char value;
+	
+	/* Initialize global help variables */
+	if( x_center == 0.0 || y_center == 0.0 || z_center == 0.0 )
+	{
+		x_center = .5 * sizex;
+		y_center = .5 * sizey;
+		z_center = .5 * sizez;
+	}
+	
+	/* Go through all voxels and compare them to the volume dataset. If the
+	 * the value is in the specified range, draw a cube at that location. */
+	for( x = 0; x < nx; x++ )
+	{
+		for( y = 0; y < ny; y++ )
+		{
+			for( z = 0; z < nz; z++ )
+			{
+				if( (value = volume[voxel2idx(x, y, z)]) >= isovalue - epsilon
+				    && value <= isovalue + epsilon )
+				{
+				    glPushMatrix();
+				    
+				    glTranslatef(x + x_center, y + y_center, z + z_center);
+				    glScalef(sizex, sizey, sizez);
+					glutSolidCube(1.0);
+					
+				    glPopMatrix();
+				}
+			}
+		}
+	}
+}
+
+/* Fill the vertex array based on the current iso-value range,
+   so the array can be drawn as GL_POINTS, with one point per voxel
+   to be shown.
+
+   Be sure to set num_vertices_in_array.
+*/
+
+/* Add an (x,y,z)-value to the vertices array */
+void
+addVertex(int *index, float x, float y, float z)
+{
+	vertices[(*index)++] = x;
+    vertices[(*index)++] = y;
+    vertices[(*index)++] = z;
+    num_vertices_in_array++;
+}
+
+/* Add an (x,y,z)-value to the normals array */
+void
+addNormal(int index, float x, float y, float z)
+{
+	normals[index++] = x;
+    normals[index++] = y;
+    normals[index] = z;
+}
+
+/* Draw the corners of a quad in the X-dimension (all points have the
+ * same x-coordinate). Add the corner normals to the normals array. */
+void
+addQuadX(int *index, float x, float y, float z,
+	float w, float h, float normal_x)
+{
+	addNormal(*index, normal_x, 0, 0);
+	addVertex(index, x, y, z);
+	addNormal(*index, normal_x, 0, 0);
+	addVertex(index, x, y + w, z);
+	addNormal(*index, normal_x, 0, 0);
+	addVertex(index, x, y + w, z + h);
+	addNormal(*index, normal_x, 0, 0);
+	addVertex(index, x, y, z + h);
+}
+
+/* Draw the corners of a quad in the Y-dimension (all points have the
+ * same y-coordinate). Add the corner normals to the normals array. */
+void
+addQuadY(int *index, float x, float y, float z,
+	float w, float h, float normal_y)
+{
+	addNormal(*index, 0, normal_y, 0);
+	addVertex(index, x, y, z);
+	addNormal(*index, 0, normal_y, 0);
+	addVertex(index, x + w, y, z);
+	addNormal(*index, 0, normal_y, 0);
+	addVertex(index, x + w, y, z + h);
+	addNormal(*index, 0, normal_y, 0);
+	addVertex(index, x, y, z + h);
+}
+
+/* Draw the corners of a quad in the Z-dimension (all points have the
+ * same z-coordinate). Add the corner normals to the normals array. */
+void
+addQuadZ(int *index, float x, float y, float z,
+	float w, float h, float normal_z)
+{
+	addNormal(*index, 0, 0, normal_z);
+	addVertex(index, x, y, z);
+	addNormal(*index, 0, 0, normal_z);
+	addVertex(index, x, y + h, z);
+	addNormal(*index, 0, 0, normal_z);
+	addVertex(index, x + w, y + h, z);
+	addNormal(*index, 0, 0, normal_z);
+	addVertex(index, x + w, y, z);
+}
+
+void FillArrayWithPoints(void)
+{
+	int x, y, z, index;
+	char value;
+	
+	/* Initialize global help variables */
+	if( x_center == 0.0 || y_center == 0.0 || z_center == 0.0 )
+	{
+		x_center = .5 * sizex;
+		y_center = .5 * sizey;
+		z_center = .5 * sizez;
+	}
+	
+	/* Clear array counters */
+	num_vertices_in_array = index = 0;
+	
+	/* Go through all voxels and compare them to the volume dataset. If the
+	 * the value is in the specified range, add a point at that location. */
+	for( x = 0; x < nx; x++ )
+	{
+		for( y = 0; y < ny; y++ )
+		{
+			for( z = 0; z < nz; z++ )
+			{
+				if( (value = volume[voxel2idx(x, y, z)]) >= isovalue - epsilon
+				    && value <= isovalue + epsilon )
+				{
+					addVertex(&index, x + x_center, y + y_center, z + z_center);
+					
+					/* Check if the next point will fit in the vertices array */
+					if( num_vertices_in_array == MAX_VERTICES_IN_ARRAY )
+					{
+						puts("vertex array full, stopped filling");
+						return;
+					}
+				}
+			}
+		}
+	}
+}
+
+/* Fill the vertex and normal arrays based on the current iso-value range,
+   so the arrays can be drawn as GL_QUADS, with one cube per voxel
+   to be shown (and six quads per cube).
+
+   Be sure to set num_vertices_in_array.
+*/
+
+void FillArrayWithCubes(void)
+{
+	int x, y, z, index;
+	char value;
+	
+	/* Initialize global help variables */
+	if( normal_x_size == 0.0 || normal_y_size == 0.0 )
+	{
+		// Set normal sizes relative to the 
+		normal_x_size = sizez / sizex;
+		normal_y_size = sizez / sizey;
+	}
+	
+	/* Clear array counters */
+	num_vertices_in_array = index = 0;
+	
+	/* Go through all voxels and compare them to the volume dataset. If the
+	 * the value is in the specified range, add a cube at that location. */
+	for( x = 0; x < nx; x++ )
+	{
+		for( y = 0; y < ny; y++ )
+		{
+			for( z = 0; z < nz; z++ )
+			{
+				if( (value = volume[voxel2idx(x, y, z)]) >= isovalue - epsilon
+				    && value <= isovalue + epsilon )
+				{
+					/* Check if the cube will fit in the vertices array */
+					if( num_vertices_in_array + 24 > MAX_VERTICES_IN_ARRAY )
+					{
+						puts("vertex array full, stopped filling");
+						return;
+					}
+					
+					/* Back planes of the cube */
+					addQuadX(&index, x, y, z, sizey, sizez, -normal_x_size);
+					addQuadY(&index, x, y, z, sizex, sizez, -normal_y_size);
+					addQuadZ(&index, x, y, z, sizex, sizey, -1.0);
+					
+					/* Front planes of the cube */
+					addQuadX(&index, x + sizex, y, z, sizey, sizez, normal_x_size);
+					addQuadY(&index, x, y + sizey, z, sizex, sizez, normal_y_size);
+					addQuadZ(&index, x, y, z + sizez, sizex, sizey, 1.0);
+				}
+			}
+		}
+	}
+}
+
+/* Restart the framerate timer (also used at keypress-events) */
+void
+reset_timer(void)
+{
+	gettimeofday(&start, NULL);
+	timer = TIMER_FRAMERATE + 1;
+}
+
+void DrawScene(void)
+{
+    /* clear the draw buffer */
+    glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
+	
+    /* set the model-view matrix */
+    SetupCamera();
+	
+    /* draw an outline of where the volume resides */
+    DrawVolumeAxes();
+
+    /* draw the volume in the chosen mode */
+    DrawVolumeUsingCurrentDisplayMode();
+	
+    glFinish();
+    
+    /* Stop framerate timer */
+    if( display_fps_counter )
+    {
+    	if( timer == TIMER_FRAMERATE )
+		{
+			gettimeofday(&end, NULL);
+			
+			/* Print FPS (rounded to complete frames) */
+			printf("Framerate: %d \n", (int)(TIMER_FRAMERATE / (
+				end.tv_sec - start.tv_sec + (end.tv_usec - start.tv_usec) * 1e-6
+			) + .5));
+			fflush(stdout);
+		}
+		
+		timer = (timer + 1) % (TIMER_FRAMERATE + 1);
+	}
+	
+	/* Start framerate timer */
+    if( display_fps_counter && !timer )
+	    gettimeofday(&start, NULL);
+    
+    /* finally, swap the draw buffers to make the frame appear on screen */
+    glutSwapBuffers();
+}
+
+/* Draw a set of colored X, Y and Z axes that match the size (and location)
+   of the volume, so we can see where output should appear */
+void
+DrawVolumeAxes(void)
+{
+    glPushAttrib(GL_LIGHTING_BIT);
+    glDisable(GL_LIGHTING);
+
+    glBegin(GL_LINES);
+
+    glColor3f(1, 0, 0);
+    glVertex3f(0, 0, 0);
+    glVertex3f(nx*sizex, 0, 0);
+
+    glColor3f(0, 1, 0);
+    glVertex3f(0, 0, 0);
+    glVertex3f(0, ny*sizey, 0);
+
+    glColor3f(0, 0, 1);
+    glVertex3f(0, 0, 0);
+    glVertex3f(0, 0, nz*sizez);
+	
+    glEnd();
+
+    glPopAttrib();
+}
+
+void DrawVolumeUsingCurrentDisplayMode(void)
+{
+    if (use_arrays)
+    {
+        if (regenerate_arrays == 1)
+        {
+            printf("Filling vertex/normal arrays... ");
+            fflush(stdout);
+			
+            switch (display_mode)
+            {
+            case 0:
+                FillArrayWithPoints();
+                break;
+            case 1:
+                FillArrayWithCubes();
+                break;
+            }
+			
+            printf("done, %d array vertices used (1 per point, 4 per quad)\n", num_vertices_in_array);
+			
+            regenerate_arrays = 0;
+        }
+
+        glEnableClientState(GL_VERTEX_ARRAY);
+        glVertexPointer(3, GL_FLOAT, 0, vertices);
+		
+        if (display_mode > 0)
+        {
+            glEnableClientState(GL_NORMAL_ARRAY);
+            glNormalPointer(GL_FLOAT, 0, normals);
+        }
+    }
+	
+    glColor3f(0.6, 0.0, 0.0);
+	
+    if (display_mode == 0)
+        glDisable(GL_LIGHTING);
+    else
+        glEnable(GL_LIGHTING);
+
+    if (display_mode == 0)
+    {
+        /* points */
+        glPointSize(POINT_SIZE);
+        if (use_arrays)
+            glDrawArrays(GL_POINTS, 0, num_vertices_in_array);
+        else	
+    if (display_mode == 0)
+            DrawVolumeAsPoints();
+    }
+    else if (display_mode == 1)
+    {
+        /* cubes */
+        if (use_arrays)
+            glDrawArrays(GL_QUADS, 0, num_vertices_in_array);
+        else
+        {
+            glEnable(GL_RESCALE_NORMAL);
+            DrawVolumeAsCubes();
+            glDisable(GL_RESCALE_NORMAL);
+        }
+    }
+
+    if (use_arrays)
+    {
+        glDisableClientState(GL_VERTEX_ARRAY);
+        if (display_mode > 0)
+            glDisableClientState(GL_NORMAL_ARRAY);
+    }
+}
+
+void SetupCamera(void)
+{
+    GLfloat light_position[4];
+
+    glLoadIdentity();
+
+    // Verbose, but straightforward way, of positioning the camera and lightsource.
+    // Assume the camera's final position is (cx, cy, cz).
+    // Start with c being (camDistance, 0, 0)
+    // First rotate around Y, then around Z.
+    // Now we have c at the given distance from the origin, with specified rotation angles.
+
+    float	cx, cy, cz;
+    float	t;
+    float 	beta, gamma;
+
+    // degrees -> radians
+    beta = camAzimuth / 180.0 * 3.1415926535;
+    gamma = camRotZ / 180.0 * 3.1415926535;
+
+    cx = camDistance;
+    cy = cz = 0.0;
+
+    // Rotate around Y
+    t = cx;
+    cx = cx * cos(beta) - cz * sin(beta);
+    cz = t * sin(beta) + cz * cos(beta);
+
+    // Rotate around Z
+    t = cx;
+    cx = cx * cos(gamma) + cy * sin(gamma);
+    cy = -t * sin(gamma) + cy * cos(gamma);
+
+    gluLookAt (cx, cy, cz,  0.0, 0.0, 0.0,  0.0, 0.0, 1.0);
+
+    // Finally, translate because the lookat point is at the center of the volume.
+    glTranslatef(-0.5*nx*sizex, -0.5*ny*sizey, -0.5*nz*sizez);
+
+    // Place the light source at the camera position (head light)
+    light_position[0] = cx + 0.5*nx*sizex;
+    light_position[1] = cy + 0.5*ny*sizey;
+    light_position[2] = cz + 0.5*nz*sizez;
+    light_position[3] = 1.0;
+    glLightfv(GL_LIGHT0, GL_POSITION, light_position);
+}
+
+void InitOpenGL(void)
+{
+    GLfloat light_ambient[] = { 0.4, 0.4, 0.4, 0.0 };
+    GLfloat	red[] = { 1.0, 0.0, 0.0, 1.0 };
+    GLfloat mat_no_specular[] = { 0.0, 0.0, 0.0, 1.0 };
+
+    glClearColor(0.7, 0.7, 1, 1);
+
+    glEnable(GL_COLOR_MATERIAL);
+
+    glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, red);
+    glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, mat_no_specular);
+
+    glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
+    glEnable(GL_LIGHTING);
+    glEnable(GL_LIGHT0);
+    glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, 1);
+    glLightModeli(GL_LIGHT_MODEL_LOCAL_VIEWER, 1);
+
+    glDepthFunc(GL_LEQUAL);
+    glEnable(GL_DEPTH_TEST);
+
+    glDisable(GL_CULL_FACE);
+
+    glShadeModel(GL_FLAT);
+    //glShadeModel(GL_SMOOTH);
+}
+
+void ReSizeScene(int Width, int Height)
+{
+    if (Height==0)
+        Height=1;
+
+    glViewport(0, 0, Width, Height);
+
+    glMatrixMode(GL_PROJECTION);
+
+    glLoadIdentity();
+    gluPerspective(45.0f,(GLfloat)Width/(GLfloat)Height, 0.1f, 10000.0f);
+
+    glMatrixMode(GL_MODELVIEW);
+    glLoadIdentity ();
+}
+
+void keyPressed(unsigned char key, int x, int y)
+{
+    int	redraw=0;
+
+    /* keep gcc happy, as we don't use these parameters */
+    (void)x;
+    (void)y;
+
+    switch (key)
+    {
+        case 'q':
+            exit(-1);
+            break;
+
+        case 'b':
+            backface_culling = 1 - backface_culling;
+            if (backface_culling)
+            {
+                glEnable(GL_CULL_FACE);
+                printf("Backface culling is now enabled\n");
+            }
+            else
+            {
+                glDisable(GL_CULL_FACE);
+                printf("Backface culling is now disabled\n");
+            }
+            glutPostRedisplay();
+            break;
+
+        case 'p':
+            /* switch to points mode */
+            display_mode = 0;
+            redraw = 1;
+            break;
+        case 'c':
+            /* switch to cubes mode */
+            display_mode = 1;
+            redraw = 1;
+            break;
+
+        case '[':
+            /* decrease isovalue */
+            {
+                int newvalue = isovalue-10;
+                if (newvalue < 0)
+                    isovalue = 0;
+                else
+                    isovalue = newvalue;
+            }
+            printf("Setting isovalue to %d\n", isovalue);
+            redraw = 1;
+            break;
+        case ']':
+            /* increase isovalue */
+            {
+                int newvalue = isovalue+10;
+                if (newvalue > 255)
+                    isovalue = 255;
+                else
+                    isovalue = newvalue;
+            }
+            printf("Setting isovalue to %d\n", isovalue);
+            redraw = 1;
+            break;
+
+        /* handle isovalue/epsilon entered by number */
+        case '0':
+            entered_number = entered_number*10;
+            break;
+        case '1':
+            entered_number = entered_number*10 + 1;
+            break;
+        case '2':
+            entered_number = entered_number*10 + 2;
+            break;
+        case '3':
+            entered_number = entered_number*10 + 3;
+            break;
+        case '4':
+            entered_number = entered_number*10 + 4;
+            break;
+        case '5':
+            entered_number = entered_number*10 + 5;
+            break;
+        case '6':
+            entered_number = entered_number*10 + 6;
+            break;
+        case '7':
+            entered_number = entered_number*10 + 7;
+            break;
+        case '8':
+            entered_number = entered_number*10 + 8;
+            break;
+        case '9':
+            entered_number = entered_number*10 + 9;
+            break;
+
+        case 'i':
+            /* update isovalue with number entered */
+            isovalue = entered_number % 256;
+            entered_number = 0;
+
+            printf("Setting isovalue to %d\n", isovalue);
+            redraw = 1;
+            break;
+
+        case '{':
+            /* decrease epsilon */
+            {
+                int newvalue = epsilon - 2;
+                if (newvalue < 0)
+                    epsilon = 0;
+                else
+                    epsilon = newvalue;
+            }
+            printf("Setting epsilon to %d\n", epsilon);
+            redraw = 1;
+            break;
+        case '}':
+            /* increase epsilon */
+            {
+                int newvalue = epsilon + 2;
+                if (newvalue > 255)
+                    epsilon = 255;
+                else
+                    epsilon = newvalue;
+            }
+            printf("Setting epsilon to %d\n", epsilon);
+            redraw = 1;
+            break;
+
+        case 'e':
+            /* update epsilon with number entered */
+            epsilon = entered_number % 256;
+            entered_number = 0;
+
+            printf("Setting epsilon to %d\n", epsilon);
+            redraw = 1;
+            break;
+
+        case 'f':
+            /* enable/display FPS counter display */
+            display_fps_counter = 1 - display_fps_counter;
+            break;
+        case 'a':
+            use_arrays = 1 - use_arrays;
+            if (use_arrays)
+                printf("Now using arrays\n");
+            else
+                printf("Stopped using arrays\n");
+            glutPostRedisplay();
+            break;
+    }
+    
+    reset_timer();
+
+    if (redraw)
+    {
+        regenerate_arrays = 1;
+        glutPostRedisplay();
+    }
+}
+
+void specialKeyPressed(int key, int x, int y)
+{
+    /* keep gcc happy, as we don't use these parameters */
+    (void)key;
+    (void)x;
+    (void)y;
+}
+
+static void
+mouseFunc(int button, int state, int x, int y)
+{
+    // guard against both left and right buttons being pressed at the same time,
+    // by only responding when a mouse button is pressed while another one
+    // hasn't been pressed yet
+    if (state == GLUT_DOWN && mouse_mode == 0)
+    {
+        if (button == GLUT_LEFT_BUTTON)
+        {
+            mouse_mode = GLUT_LEFT_BUTTON;
+
+            saved_camRotZ = camRotZ;
+            saved_camAzimuth = camAzimuth;
+
+            mx = x;
+            my = y;
+        }
+        else if (button == GLUT_RIGHT_BUTTON)
+        {
+            mouse_mode = GLUT_RIGHT_BUTTON;
+
+            saved_camDistance = camDistance;
+
+            my = y;
+        }
+    }
+    else if (state == GLUT_UP && button == mouse_mode)
+    {
+        // pressed button released
+        mouse_mode = 0;
+    }
+
+}
+
+static void
+motionFunc(int x, int y)
+{
+    int	dx, dy;
+
+    if (mouse_mode == GLUT_LEFT_BUTTON)
+    {
+        dx = mx - x;
+        dy = my - y;
+
+        camRotZ = saved_camRotZ - dx * 0.25;
+        camAzimuth = saved_camAzimuth - dy * 0.25;
+
+        if (camAzimuth > 89.99)
+            camAzimuth = 89.99;
+        else if (camAzimuth < -89.99)
+            camAzimuth = -89.99;
+    }
+    else if (mouse_mode == GLUT_RIGHT_BUTTON)
+    {
+        dy = my - y;
+
+        camDistance = saved_camDistance - dy * sizex;
+        if (camDistance < 0.01)
+            camDistance = 0.01;
+    }
+}
+
+static void
+initialize_volume(const char *fname, unsigned char iso)
+{
+    read_volume(fname);
+
+    isovalue = iso;
+    if (epsilon > 0)
+        printf("Iso-value = %d (+/- %d)\n", isovalue, epsilon);
+    else
+        printf("Iso-value = %d\n", isovalue);
+
+    // Initial distance from camera position to center of volume
+    camDistance = 2.0 * nx * sizex;
+}
+
+int
+main(int argc, char **argv)
+{
+    glutInit(&argc, argv);
+
+    if (argc != 3)
+    {
+        printf("usage: %s datafile isovalue\n", argv[0]);
+        exit(0);
+    }
+
+    initialize_volume(argv[1], atoi(argv[2]));
+
+    glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_ALPHA | GLUT_DEPTH);
+    glutInitWindowSize(640, 480);
+    glutInitWindowPosition(0, 0);
+    window = glutCreateWindow("OpenGL Framework");
+
+    glutDisplayFunc(&DrawScene);
+    glutIdleFunc(&DrawScene);
+    glutReshapeFunc(&ReSizeScene);
+    glutSpecialFunc(&specialKeyPressed);
+    glutKeyboardFunc(&keyPressed);
+    glutMouseFunc(&mouseFunc);
+    glutMotionFunc(&motionFunc);
+
+    InitOpenGL();
+
+    glutMainLoop();
+
+    return 1;
+}
+
+
+
+
+

graphics/ass8/v3math.h

+#ifndef V3MATH_H
+#define V3MATH_H
+
+#include <math.h>
+
+typedef struct
+{
+    float   x, y, z;
+}
+vec3;
+
+// Create a new 3-vector of floats
+static inline vec3
+v3_create(float x, float y, float z)
+{
+    vec3 res;
+    res.x = x;
+    res.y = y;
+    res.z = z;
+    return res;
+}
+
+// Return -a
+static inline vec3
+v3_negate(vec3 a)
+{
+    vec3 res;
+    res.x = - a.x;
+    res.y = - a.y;
+    res.z = - a.z;
+    return res;
+}
+
+// Return a + b
+static inline vec3
+v3_add(vec3 a,vec3 b)
+{
+    vec3 res;
+    res.x = a.x+b.x;
+    res.y = a.y+b.y;
+    res.z = a.z+b.z;
+    return res;
+}
+
+// Return a - b
+static inline vec3
+v3_subtract(vec3 a, vec3 b)
+{
+    vec3 res;
+    res.x = a.x-b.x;
+    res.y = a.y-b.y;
+    res.z = a.z-b.z;
+    return res;
+}
+
+// Return a / |a|
+static inline vec3
+v3_normalize(vec3 a)
+{
+    vec3 res;
+    double l = sqrt(a.x*a.x + a.y*a.y + a.z*a.z);
+
+    res = a;
+    res.x /= l;
+    res.y /= l;
+    res.z /= l;
+
+    return res;
+}
+
+// Return a ^ b
+static inline vec3
+v3_crossprod(vec3 a, vec3 b)
+{
+    vec3 res;
+    res.x = a.y*b.z - a.z*b.y;
+    res.y = a.z*b.x - a.x*b.z;
+    res.z = a.x*b.y - a.y*b.x;
+    return res;
+}
+
+// Return a * b
+static inline float
+v3_dotprod(vec3 a, vec3 b)
+{
+    return a.x*b.x + a.y*b.y + a.z*b.z;
+}
+
+// Return a*s
+static inline vec3
+v3_multiply(vec3 a, float s)
+{
+    vec3 res;
+    res.x = a.x*s;
+    res.y = a.y*s;
+    res.z = a.z*s;
+    return res;
+}
+
+// Return |a|
+static inline float
+v3_length(vec3 a)
+{
+    return sqrt(a.x*a.x + a.y*a.y + a.z*a.z);
+}
+
+// Return the i-th component of a, i.e. for i=0
+// this returns a.x
+static inline float
+v3_component(vec3 a, int i)
+{
+    if (i == 0)
+        return a.x;
+    else if (i == 1)
+        return a.y;
+    else
+        return a.z;
+}
+
+// Set the i-th component of a to v
+static inline vec3
+v3_set_component(vec3 a, int i, float v)
+{
+    vec3    res = a;
+
+    if (i == 0)
+        res.x = v;
+    else if (i == 1)
+        res.y = v;
+    else
+        res.z = v;
+
+    return res;
+}
+
+#endif

graphics/ass8/volume.c

+/* Computer Graphics, Assignment, Volume rendering with cubes/points
+ *
+ * Description ..... Creates OpenGL window and draws the scene.
+ * Date ............ 29.10.2008
+ * Created by ...... Paul Melis
+ *
+ * Student name .... Sander van Veen & Taddeus Kroes
+ * Student email ... sandervv@gmail.com & taddeuskroes@hotmail.com
+ * Collegekaart .... 6167969 & 6054129
+ * Date ............ 07.11.2010
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "volume.h"
+
+/* The voxels of the volume dataset, stored as a one-dimensional array */
+unsigned char   *volume;
+
+/* The dimensions of the volume dataset */
+int     nx, ny, nz;
+
+/* The size of a voxel */
+float   sizex, sizey, sizez;
+
+/* Utility function to convert the index of a voxel
+   into an index in the volume array above */
+int
+voxel2idx(int i, int j, int k)
+{
+    return (k*ny + j)*nx + i;
+}
+
+/* Utility function to read a volume dataset from a VTK file.
+   This will store the data in the "volume" array and update the dimension
+   and size values. */
+
+void
+read_volume(const char *fname)
+{
+    FILE *f;
+    char s[256];
+    unsigned int nvoxels;
+
+    printf("Reading %s\n", fname);
+    f = fopen(fname, "rb");
+
+    if (!f)
+    {
+        fprintf(stderr, "read_volume(): Could not open file '%s' for reading!\n", fname);
+        exit(-1);
+    }
+
+    // header line
+    fgets(s, 255, f);
+
+    // comment line
+    fgets(s, 255, f);
+
+    // BINARY
+    fgets(s, 255, f);
+
+    // DATASET STRUCTURED_POINTS
+    fgets(s, 255, f);
+
+    // DIMENSIONS %d %d %d
+    fscanf(f, "%s %d %d %d\n", s, &nx, &ny, &nz);
+    printf("%d x %d x %d voxels\n", nx, ny, nz);
+
+    // ASPECT_RATIO/SPACING %f %f %f
+    fscanf(f, "%s %f %f %f\n", s, &sizex, &sizey, &sizez);
+    printf("voxel sizes: %.3f, %.3f, %.3f\n", sizex, sizey, sizez);
+
+    // ORIGIN ...
+    fgets(s, 255, f);
+
+    // POINT_DATA ...
+    fgets(s, 255, f);
+
+    // SCALARS ...
+    fgets(s, 255, f);
+
+    // LOOKUP_TABLE ...
+    fgets(s, 255, f);
+
+    // allocate memory to hold the volume data and read it from file
+    nvoxels = nx * ny * nz;
+    volume = (unsigned char*)malloc(nvoxels);
+
+    if (fread(volume, 1, nvoxels, f) < nvoxels)
+    {
+        printf("WARNING: not all data could be read!\n");
+    }
+
+    fclose(f);
+}

graphics/ass8/volume.h

+#ifndef VOLUME_H
+#define VOLUME_H
+
+/* The data points in the volume dataset, stored as a one-dimensional array */
+extern unsigned char    *volume;
+
+/* The dimensions of the volume dataset in number of voxels in each
+   dimension*/
+extern int              nx, ny, nz;
+
+/* The size of a voxel for each dimension */
+extern float            sizex, sizey, sizez;
+
+/* Utility function to convert the index of a datapoint
+   into an index in the volume array above */
+int voxel2idx(int i, int j, int k);
+
+/* Utility function to read a volume dataset from a file.
+   This will store the data in the "volume" array and update the dimension
+   and size values. */
+void read_volume(const char *fname);
+
+#endif

os/ass2/report/report.tex

@@ -10,7 +10,6 @@
 \usepackage{float}
 
 \usepackage[dutch]{babel}
-\usepackage{listings}
 
 \lstset{
 language=C,