working on the transformation node system

[erebus2020] / liberebus / src / node.c

diff --git a/liberebus/src/node.c b/liberebus/src/node.c
new file mode 100644 (file)
index 0000000..593a0c7
--- /dev/null
+++ b/liberebus/src/node.c
@@ -0,0 +1,175 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "erebus.h"
+
+static struct erb_key *findkey(struct erb_track *trk, long tm);
+static int setkey(struct erb_track *trk, long key, float val);
+static float evalkey(struct erb_track *trk, long key);
+
+void erb_node_pos(struct erb_node *n, long tm, float x, float y, float z)
+{
+       setkey(n->track + ERB_TRK_X, tm, x);
+       setkey(n->track + ERB_TRK_Y, tm, y);
+       setkey(n->track + ERB_TRK_Z, tm, z);
+}
+
+void erb_node_rot(struct erb_node *n, long tm, float qx, float qy, float qz, float qw)
+{
+       setkey(n->track + ERB_TRK_QX, tm, qx);
+       setkey(n->track + ERB_TRK_QY, tm, qy);
+       setkey(n->track + ERB_TRK_QZ, tm, qz);
+       setkey(n->track + ERB_TRK_QW, tm, qw);
+}
+
+void erb_node_rot_axis(struct erb_node *n, long tm, float angle_deg, float x, float y, float z)
+{
+       cgm_quat q;
+       cgm_qrotation(&q, cgm_deg_to_rad(angle_deg), x, y, z);
+       erb_node_rot(n, tm, q.x, q.y, q.z, q.w);
+}
+
+void erb_node_scale(struct erb_node *n, long tm, float sx, float sy, float sz)
+{
+       setkey(n->track + ERB_TRK_SX, tm, sx);
+       setkey(n->track + ERB_TRK_SY, tm, sy);
+       setkey(n->track + ERB_TRK_SZ, tm, sz);
+}
+
+void erb_node_update(struct erb_node *n, long tm)
+{
+       erb_node_eval_node_matrix(n, tm, n->node_xform);
+
+       cgm_mcopy(n->inv_node_xform, n->node_xform);
+       cgm_minverse(n->inv_node_xform);
+
+       cgm_mcopy(n->xform, n->node_xform);
+       cgm_mcopy(n->inv_xform, n->inv_node_xform);
+
+       if(n->par) {
+               cgm_mmul(n->xform, n->par->xform);
+               cgm_mpremul(n->inv_xform, n->par->inv_xform);
+       }
+}
+
+void erb_node_setxform(struct erb_node *n, float *mat)
+{
+       cgm_mcopy(n->node_xform, mat);
+       cgm_mcopy(n->inv_node_xform, mat);
+       cgm_minverse(n->inv_node_xform);
+
+       cgm_mcopy(n->xform, n->node_xform);
+       cgm_mcopy(n->inv_xform, n->inv_node_xform);
+
+       if(n->par) {
+               cgm_mmul(n->xform, n->par->xform);
+               cgm_mpremul(n->inv_xform, n->par->inv_xform);
+       }
+}
+
+void erb_node_eval_pos(struct erb_node *n, long tm, cgm_vec3 *pos)
+{
+       pos->x = evalkey(n->track + ERB_TRK_X, tm);
+       pos->y = evalkey(n->track + ERB_TRK_Y, tm);
+       pos->z = evalkey(n->track + ERB_TRK_Z, tm);
+}
+
+void erb_node_eval_rot(struct erb_node *n, long tm, cgm_quat *rot)
+{
+       rot->x = evalkey(n->track + ERB_TRK_QX, tm);
+       rot->y = evalkey(n->track + ERB_TRK_QY, tm);
+       rot->z = evalkey(n->track + ERB_TRK_QZ, tm);
+       rot->w = evalkey(n->track + ERB_TRK_QW, tm);
+}
+
+void erb_node_eval_scale(struct erb_node *n, long tm, cgm_vec3 *scale)
+{
+       scale->x = evalkey(n->track + ERB_TRK_SX, tm);
+       scale->y = evalkey(n->track + ERB_TRK_SY, tm);
+       scale->z = evalkey(n->track + ERB_TRK_SZ, tm);
+}
+
+void erb_node_eval_matrix(struct erb_node *n, long tm, float *mat)
+{
+       erb_node_eval_node_matrix(n, tm, mat);
+       if(n->par) {
+               cgm_mmul(mat, n->par->xform);
+       }
+}
+
+void erb_node_eval_node_matrix(struct erb_node *n, long tm, float *mat)
+{
+       cgm_vec3 pos, scale;
+       cgm_quat rot;
+
+       erb_node_eval_pos(n, tm, &pos);
+       erb_node_eval_rot(n, tm, &rot);
+       erb_node_eval_scale(n, tm, &scale);
+
+       cgm_midentity(mat);
+       cgm_mtranslate(mat, pos.x, pos.y, pos.z);
+       cgm_mrotate_quat(mat, &rot);
+       cgm_mscale(mat, scale.x, scale.y, scale.z);
+}
+
+static struct erb_key *findkey(struct erb_track *trk, long tm)
+{
+       struct erb_key *beg, *end, *mid;
+
+       /* TODO: if num_keys < something_small, do linear search */
+       if(trk->num_keys <= 0) return 0;
+
+       beg = trk->keys;
+       end = trk->keys + trk->num_keys;
+
+       while(beg < end) {
+               mid = beg + ((end - beg) >> 1);
+
+               if(tm == mid->tm) return mid;
+               if(tm < mid->tm) {
+                       end = mid;
+               } else {
+                       beg = mid + 1;
+               }
+       }
+       return beg;
+}
+
+
+static int setkey(struct erb_track *trk, long tm, float val)
+{
+       int rest;
+       struct erb_key *key;
+
+       if((key = findkey(trk, tm)) && key->tm == tm) {
+               key->val = val;
+               return 0;
+       }
+
+       if(trk->num_keys >= trk->max_keys) {
+               int newsz = trk->max_keys ? trk->max_keys << 1 : 8;
+               void *ptr;
+
+               if(!(ptr = realloc(trk->keys, newsz * sizeof *key))) {
+                       fprintf(stderr, "erebus: failed to add keyframe (realloc track failed)\n");
+                       return -1;
+               }
+               trk->keys = ptr;
+               trk->max_keys = newsz;
+       }
+
+       key++;
+       rest = trk->num_keys - (key - trk->keys);
+       if(rest > 0) {
+               memmove(key + 1, key, rest * sizeof *key);
+       }
+       key->tm = tm;
+       key->val = val;
+       trk->num_keys++;
+       return 0;
+}
+
+static float evalkey(struct erb_track *trk, long tm)
+{
+       /* TODO */
+       return 0;
+}