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Commit 4d11ffe5 authored by Taddeüs Kroes's avatar Taddeüs Kroes
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- Worked on graohics ass9.

parent 3909dfd7
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Showing with 95 additions and 61 deletions
graphics/ass9/source/main.c
View file @ 4d11ffe5
......@@ -229,18 +229,22 @@ void FillArrayWithIsosurface(void)
triangle tri[12];
vec3 normal, *p;
// Loop through cells
for( x = 0; x < nx-1; x++ )
{
for( y = 0; y < ny-1; y++ )
{
for( z = 0; z < nz-1; z++ )
{
// Calculate triangles in cell
n = generate_cell_triangles(tri, get_cell(x, y, z), isovalue);
tri_count += n;
for( i = 0; i < n; i++ )
{
p = tri[i].p;
// Calculate the triangle normal and set it to every corner
normal = v3_normalize(v3_crossprod(
v3_subtract(p[1], p[0]),
v3_subtract(p[2], p[0])
......
graphics/ass9/source/marching_tetrahedra.c
View file @ 4d11ffe5
......@@ -12,6 +12,7 @@
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include <math.h>
#include "marching_tetrahedra.h"
/* Compute a linearly interpolated position where an isosurface cuts
......@@ -22,10 +23,14 @@ static vec3
interpolate_points(unsigned char isovalue, vec3 p1, vec3 p2,
unsigned char v1, unsigned char v2)
{
/* Initially, simply return the midpoint between p1 and p2.
So no real interpolation is done yet */
//float diff1 = fabsf((float)(isovalue - v1)),
// diff2 = fabsf((float)(isovalue - v2)),
// total = diff1 + diff2;
//vec3 v = v3_add(v3_multiply(p1, diff1/total), v3_multiply(p2, diff2/total));
return v3_add(v3_multiply(p1, 0.5), v3_multiply(p2, 0.5));
vec3 v = v3_add(v3_multiply(p1, 0.5), v3_multiply(p2, 0.5));
return v3_create(v.x * sizex, v.y * sizey, v.z * sizez);
}
/* Using the given iso-value generate triangles for the tetrahedron
......@@ -39,71 +44,94 @@ interpolate_points(unsigned char isovalue, vec3 p1, vec3 p2,
2 triangles.
*/
// Some abbreviating definitions that are used in the function below
#define ADD_VEC(i,a,b) (triangles[tri_count].p[(i)] = \
interpolate_points(isovalue, c.p[(a)], c.p[(b)], v[(a)], v[(b)]))
#define ADD_TRI(a,b,c,d,e,f) \
ADD_VEC(0,(a),(b)); ADD_VEC(1,(c),(d)); ADD_VEC(2,(e),(f)); tri_count++
static int
generate_tetrahedron_triangles(triangle *triangles, unsigned char isovalue,
cell c, int v0, int v1, int v2, int v3)
{
unsigned char *v = c.value;
vec3 *p = triangles[0].p;
int bitsystem = 0;
if(c.value[v0] > isovalue) bitsystem += 1;
if(c.value[v1] > isovalue) bitsystem += 2;
if(c.value[v2] > isovalue) bitsystem += 4;
if(c.value[v3] > isovalue) bitsystem += 8;
//vec3 *p = triangles[0].p;
int tri_count = 0;
switch( bitsystem )
// Use a 4-bit bitmask to determine the order of "black/white" points of
// the tetrahedon. Generate 0, 1 or 2 triangle(s) according to the case.
switch( (v[v0] <= isovalue ? 1 : 0) | (v[v1] <= isovalue ? 1<<1 : 0)
| (v[v2] <= isovalue ? 1<<2 : 0) | (v[v3] <= isovalue ? 1<<3 : 0) )
{
case 1: case 14: // 0001
p[0] = interpolate_points(isovalue, c.p[v0], c.p[v1], v[v0], v[v1]);
p[1] = interpolate_points(isovalue, c.p[v0], c.p[v2], v[v0], v[v2]);
p[2] = interpolate_points(isovalue, c.p[v0], c.p[v3], v[v0], v[v3]);
return 1;
case 2: case 13: // 0010
p[0] = interpolate_points(isovalue, c.p[v1], c.p[v0], v[v1], v[v0]);
p[1] = interpolate_points(isovalue, c.p[v1], c.p[v3], v[v1], v[v3]);
p[2] = interpolate_points(isovalue, c.p[v1], c.p[v2], v[v1], v[v2]);
return 1;
case 4: case 11: // 0100
p[0] = interpolate_points(isovalue, c.p[v2], c.p[v0], v[v2], v[v0]);
p[1] = interpolate_points(isovalue, c.p[v2], c.p[v1], v[v2], v[v1]);
p[2] = interpolate_points(isovalue, c.p[v2], c.p[v3], v[v2], v[v3]);
return 1;
case 8: case 7: // 1000
p[0] = interpolate_points(isovalue, c.p[v3], c.p[v0], v[v3], v[v0]);
p[1] = interpolate_points(isovalue, c.p[v3], c.p[v2], v[v3], v[v2]);
p[2] = interpolate_points(isovalue, c.p[v3], c.p[v1], v[v3], v[v1]);
return 1;
case 5: case 10: // 0101
p[0] = interpolate_points(isovalue, c.p[v0], c.p[v1], v[v0], v[v1]);
p[1] = interpolate_points(isovalue, c.p[v2], c.p[v3], v[v2], v[v3]);
p[2] = interpolate_points(isovalue, c.p[v0], c.p[v3], v[v0], v[v3]);
p = triangles[1].p;
p[0] = interpolate_points(isovalue, c.p[v0], c.p[v1], v[v0], v[v1]);
p[1] = interpolate_points(isovalue, c.p[v1], c.p[v2], v[v1], v[v2]);
p[2] = interpolate_points(isovalue, c.p[v2], c.p[v3], v[v2], v[v3]);
return 2;
case 3: case 12: // 0011
p[0] = interpolate_points(isovalue, c.p[v0], c.p[v3], v[v0], v[v3]);
p[1] = interpolate_points(isovalue, c.p[v0], c.p[v2], v[v0], v[v2]);
p[2] = interpolate_points(isovalue, c.p[v1], c.p[v3], v[v1], v[v3]);
p = triangles[1].p;
p[0] = interpolate_points(isovalue, c.p[v1], c.p[v3], v[v1], v[v3]);
p[2] = interpolate_points(isovalue, c.p[v1], c.p[v2], v[v1], v[v2]);
p[1] = interpolate_points(isovalue, c.p[v0], c.p[v2], v[v0], v[v2]);
return 2;
case 6: case 9: // 0110
p[0] = interpolate_points(isovalue, c.p[v0], c.p[v1], v[v0], v[v1]);
p[2] = interpolate_points(isovalue, c.p[v1], c.p[v3], v[v1], v[v3]);
p[1] = interpolate_points(isovalue, c.p[v2], c.p[v3], v[v2], v[v3]);
p = triangles[1].p;
p[0] = interpolate_points(isovalue, c.p[v0], c.p[v1], v[v0], v[v1]);
p[1] = interpolate_points(isovalue, c.p[v0], c.p[v2], v[v0], v[v2]);
p[2] = interpolate_points(isovalue, c.p[v2], c.p[v3], v[v2], v[v3]);
return 2;
default: // 0000
return 0;
case 0x1: case 0xE: // 0001 or 1110
ADD_TRI(v0, v1, v0, v2, v0, v3);
break;
//p[0] = interpolate_points(isovalue, c.p[v0], c.p[v1], v[v0], v[v1]);
//p[1] = interpolate_points(isovalue, c.p[v0], c.p[v2], v[v0], v[v2]);
//p[2] = interpolate_points(isovalue, c.p[v0], c.p[v3], v[v0], v[v3]);
//return 1;
case 0x2: case 0xD: // 0010 or 1101
ADD_TRI(v1, v0, v1, v3, v1, v2);
break;
//p[0] = interpolate_points(isovalue, c.p[v1], c.p[v0], v[v1], v[v0]);
//p[1] = interpolate_points(isovalue, c.p[v1], c.p[v3], v[v1], v[v3]);
//p[2] = interpolate_points(isovalue, c.p[v1], c.p[v2], v[v1], v[v2]);
//return 1;
case 0x4: case 0xB: // 0100 or 1011
ADD_TRI(v2, v0, v2, v1, v2, v3);
break;
//p[0] = interpolate_points(isovalue, c.p[v2], c.p[v0], v[v2], v[v0]);
//p[1] = interpolate_points(isovalue, c.p[v2], c.p[v1], v[v2], v[v1]);
//p[2] = interpolate_points(isovalue, c.p[v2], c.p[v3], v[v2], v[v3]);
//return 1;
case 0x8: case 0x7: // 1000 or 0111
ADD_TRI(v3, v0, v3, v2, v3, v1);
break;
//p[0] = interpolate_points(isovalue, c.p[v3], c.p[v0], v[v3], v[v0]);
//p[1] = interpolate_points(isovalue, c.p[v3], c.p[v2], v[v3], v[v2]);
//p[2] = interpolate_points(isovalue, c.p[v3], c.p[v1], v[v3], v[v1]);
//return 1;
case 0x3: case 0xC: // 0011 or 1100
ADD_TRI(v0, v3, v0, v2, v1, v3);
ADD_TRI(v1, v3, v0, v2, v1, v2);
break;
//p[0] = interpolate_points(isovalue, c.p[v0], c.p[v3], v[v0], v[v3]);
//p[1] = interpolate_points(isovalue, c.p[v0], c.p[v2], v[v0], v[v2]);
//p[2] = interpolate_points(isovalue, c.p[v1], c.p[v3], v[v1], v[v3]);
//p = triangles[1].p;
//p[0] = interpolate_points(isovalue, c.p[v1], c.p[v3], v[v1], v[v3]);
//p[2] = interpolate_points(isovalue, c.p[v1], c.p[v2], v[v1], v[v2]);
//p[1] = interpolate_points(isovalue, c.p[v0], c.p[v2], v[v0], v[v2]);
//return 2;
case 0x5: case 0xA: // 0101 or 1010
ADD_TRI(v0, v1, v2, v3, v0, v3);
ADD_TRI(v0, v1, v1, v2, v2, v3);
break;
//p[0] = interpolate_points(isovalue, c.p[v0], c.p[v1], v[v0], v[v1]);
//p[1] = interpolate_points(isovalue, c.p[v2], c.p[v3], v[v2], v[v3]);
//p[2] = interpolate_points(isovalue, c.p[v0], c.p[v3], v[v0], v[v3]);
//p = triangles[1].p;
//p[0] = interpolate_points(isovalue, c.p[v0], c.p[v1], v[v0], v[v1]);
//p[1] = interpolate_points(isovalue, c.p[v1], c.p[v2], v[v1], v[v2]);
//p[2] = interpolate_points(isovalue, c.p[v2], c.p[v3], v[v2], v[v3]);
//return 2;
case 0x6: case 0x9: // 0110 or 1001
ADD_TRI(v0, v1, v2, v3, v1, v3);
ADD_TRI(v0, v1, v0, v2, v2, v3);
break;
//p[0] = interpolate_points(isovalue, c.p[v0], c.p[v1], v[v0], v[v1]);
//p[2] = interpolate_points(isovalue, c.p[v1], c.p[v3], v[v1], v[v3]);
//p[1] = interpolate_points(isovalue, c.p[v2], c.p[v3], v[v2], v[v3]);
//p = triangles[1].p;
//p[0] = interpolate_points(isovalue, c.p[v0], c.p[v1], v[v0], v[v1]);
//p[1] = interpolate_points(isovalue, c.p[v0], c.p[v2], v[v0], v[v2]);
//p[2] = interpolate_points(isovalue, c.p[v2], c.p[v3], v[v2], v[v3]);
//return 2;
default: // 0000 or 1111
break;
}
return tri_count;
}
/* Generate triangles for a single cell for the given iso-value. This function
......@@ -118,9 +146,11 @@ generate_tetrahedron_triangles(triangle *triangles, unsigned char isovalue,
int
generate_cell_triangles(triangle *triangles, cell c, unsigned char isovalue)
{
// Indices to cell corners for each tetrahedon (6 * 4 indices)
const int points[24] = {0,1,3,7,0,2,6,7,0,1,5,7,0,2,3,7,0,4,5,7,0,4,6,7};
int i, tri_count = 0;
// Generate triangles for each tetrahedon
for( i = 0; i < 21; i += 4 )
{
tri_count += generate_tetrahedron_triangles(triangles + tri_count,
......
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