--- /dev/null
+#include <stdio.h>
+#include <string.h>
+#include "cgmath/cgmath.h"
+#include "metasurf.h"
+#include "metaobj.h"
+#include "util.h"
+
+static void upd_sflake(struct mobject *mobj, float t);
+static float eval_sflake(struct mobject *mobj, cgm_vec3 *pos);
+static int num_balls(int depth);
+static int gen_sflake(cgm_vec4 *sarr, int num, int depth, float x, float y, float z, float rad);
+
+static void upd_sgi(struct mobject *mobj, float t);
+static float eval_sgi(struct mobject *mobj, cgm_vec3 *pos);
+static float capsule_distsq(struct mcapsule *c, cgm_vec3 *pos);
+
+/* ---- sphereflake ---- */
+#define SF_MAX_DEPTH 2
+static cgm_vec4 *sfsph;
+
+struct mobject *metaobj_sflake(void)
+{
+ struct mobject *mobj;
+
+ mobj = calloc_nf(1, sizeof *mobj);
+
+ mobj->num_balls = num_balls(SF_MAX_DEPTH);
+ mobj->balls = malloc_nf(mobj->num_balls * sizeof *mobj->balls);
+ sfsph = malloc_nf(mobj->num_balls * sizeof *sfsph);
+
+ gen_sflake(sfsph, 0, SF_MAX_DEPTH, 0, 0, 0, 20);
+
+ mobj->update = upd_sflake;
+ mobj->eval = eval_sflake;
+ return mobj;
+}
+
+static void upd_sflake(struct mobject *mobj, float t)
+{
+ int i;
+ struct mball *ball = mobj->balls;
+ float mat[16];
+
+ cgm_midentity(mat);
+ cgm_mrotate_x(mat, t);
+ cgm_mrotate_y(mat, t);
+ cgm_mtranslate(mat, mobj->pos.x, mobj->pos.y, mobj->pos.z);
+
+ for(i=0; i<mobj->num_balls; i++) {
+ cgm_vcons(&ball->pos, sfsph[i].x, sfsph[i].y, sfsph[i].z);
+ cgm_vmul_m4v3(&ball->pos, mat);
+ ball->energy = sfsph[i].w;
+ ball++;
+ }
+}
+
+static float eval_sflake(struct mobject *mobj, cgm_vec3 *pos)
+{
+ int i;
+ float dsq, energy = 0.0f;
+ struct mball *ball = mobj->balls;
+
+ for(i=0; i<mobj->num_balls; i++) {
+ dsq = cgm_vdist_sq(&ball->pos, pos);
+ energy += ball->energy / dsq;
+ ball++;
+ }
+ return energy;
+}
+
+static int num_balls(int depth)
+{
+ if(!depth) return 0;
+ return num_balls(depth - 1) * 6 + 1;
+}
+
+static int gen_sflake(cgm_vec4 *sarr, int num, int depth, float x, float y, float z, float rad)
+{
+ int subnum;
+ float subrad, offs;
+
+ if(!depth) return 0;
+
+ sarr[num].x = x;
+ sarr[num].y = y;
+ sarr[num].z = z;
+ sarr[num].w = rad;
+ num++;
+
+ subrad = rad * 0.2f;
+ offs = rad * 0.16f;
+
+ subnum = 0;
+ subnum += gen_sflake(sarr, num + subnum, depth - 1, x + offs, y, z, subrad);
+ subnum += gen_sflake(sarr, num + subnum, depth - 1, x - offs, y, z, subrad);
+ subnum += gen_sflake(sarr, num + subnum, depth - 1, x, y + offs, z, subrad);
+ subnum += gen_sflake(sarr, num + subnum, depth - 1, x, y - offs, z, subrad);
+ subnum += gen_sflake(sarr, num + subnum, depth - 1, x, y, z + offs, subrad);
+ subnum += gen_sflake(sarr, num + subnum, depth - 1, x, y, z - offs, subrad);
+ return subnum + 1;
+}
+
+/* ---- SGI logo ---- */
+
+static const cgm_vec3 sgiv[] = {
+ {2.794170, 4.254175, 2.738066},
+ {2.794170, 4.254174, -4.358471},
+ {-2.173414, 4.254174, -4.358471},
+ {-2.173414, -2.842363, -4.358470},
+ {4.923134, -2.842363, -4.358471},
+ {4.923134, 2.125212, -4.358471},
+ {4.923134, 2.125212, 2.738066},
+ {4.923134, -4.971326, 2.738067},
+ {4.923134, -4.971326, -2.229511},
+ {-2.173413, -4.971326, -2.229511},
+ {-2.173413, -4.971325, 4.867042},
+ {2.794170, -4.971325, 4.867042},
+ {2.794170, 2.125213, 4.867042},
+ {-4.302382, 2.125213, 4.867042},
+ {-4.302383, -2.842362, 4.867042},
+ {-4.302382, -2.842363, -2.229511},
+ {-4.302382, 4.254175, -2.229512},
+ {-4.302383, 4.254175, 2.738066}
+};
+#define NUM_SGI_VERTS (sizeof sgiv / sizeof *sgiv)
+static float sgimat[16];
+
+struct mobject *metaobj_sgi(void)
+{
+ int i;
+ struct mobject *mobj;
+
+ mobj = calloc_nf(1, sizeof *mobj);
+
+ cgm_midentity(sgimat);
+ cgm_mrotate_y(sgimat, -M_PI / 4.0f);
+ cgm_mrotate_x(sgimat, M_PI / 4.0f);
+ cgm_mtranslate(sgimat, 0, -4, 0);
+
+ mobj->num_caps = NUM_SGI_VERTS;
+ mobj->caps = calloc_nf(mobj->num_caps, sizeof *mobj->caps);
+
+ for(i=0; i<mobj->num_caps; i++) {
+ mobj->caps[i].energy = 0.7;
+ }
+
+ mobj->update = upd_sgi;
+ mobj->eval = eval_sgi;
+ return mobj;
+}
+
+static void upd_sgi(struct mobject *mobj, float t)
+{
+ int i;
+ float mat[16];
+ cgm_vec3 vpos[NUM_SGI_VERTS];
+
+ cgm_mcopy(mat, sgimat);
+ cgm_mrotate_y(mat, t);
+ cgm_mtranslate(mat, mobj->pos.x, mobj->pos.y, mobj->pos.z);
+
+ for(i=0; i<NUM_SGI_VERTS; i++) {
+ vpos[i] = sgiv[i];
+ cgm_vscale(vpos + i, 0.5);
+ cgm_vmul_m4v3(vpos + i, mat);
+ }
+
+ for(i=0; i<NUM_SGI_VERTS; i++) {
+ mobj->caps[i].end[0] = vpos[i];
+ mobj->caps[i].end[1] = vpos[(i + 1) % NUM_SGI_VERTS];
+ mobj->caps[i].len = cgm_vdist(mobj->caps[i].end, mobj->caps[i].end + 1);
+ }
+}
+
+static float eval_sgi(struct mobject *mobj, cgm_vec3 *pos)
+{
+ int i;
+ float dsq, val = 0.0f;
+
+ for(i=0; i<mobj->num_caps; i++) {
+ dsq = capsule_distsq(mobj->caps + i, pos);
+ val += mobj->caps[i].energy / dsq;
+ }
+
+ return val;
+}
+
+static float capsule_distsq(struct mcapsule *c, cgm_vec3 *pos)
+{
+ float t;
+ cgm_vec3 pp, dir, pdir;
+
+ dir = c->end[1]; cgm_vsub(&dir, c->end);
+ if(c->len != 0.0f) {
+ float s = 1.0f / c->len;
+ dir.x *= s;
+ dir.y *= s;
+ dir.z *= s;
+ }
+ pdir = *pos; cgm_vsub(&pdir, c->end);
+ t = cgm_vdot(&dir, &pdir);
+
+ if(t < 0.0f) {
+ return cgm_vdist_sq(c->end, pos);
+ }
+ if(t > c->len) {
+ return cgm_vdist_sq(c->end + 1, pos);
+ }
+
+ pp = c->end[0];
+ cgm_vadd_scaled(&pp, &dir, t);
+ return cgm_vdist_sq(&pp, pos);
+}
projects / metatoy / blobdiff