# HG changeset patch
# User John Tsiombikas <nuclear@mutantstargoat.com>
# Date 1326521450 -7200
# Node ID 38489ad82bf427faeeffab2c18be0b3c2468e386
# Parent  8c6d64af9505d787a9dbf57b5fb05befefb20022
foo

diff -r 8c6d64af9505 -r 38489ad82bf4 src/dynarr.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/dynarr.c	Sat Jan 14 08:10:50 2012 +0200
@@ -0,0 +1,122 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "dynarr.h"
+
+/* The array descriptor keeps auxilliary information needed to manipulate
+ * the dynamic array. It's allocated adjacent to the array buffer.
+ */
+struct arrdesc {
+	int nelem, szelem;
+	int max_elem;
+	int bufsz;	/* not including the descriptor */
+};
+
+#define DESC(x)		((struct arrdesc*)((char*)(x) - sizeof(struct arrdesc)))
+
+void *dynarr_alloc(int elem, int szelem)
+{
+	struct arrdesc *desc;
+
+	if(!(desc = malloc(elem * szelem + sizeof *desc))) {
+		return 0;
+	}
+	desc->nelem = desc->max_elem = elem;
+	desc->szelem = szelem;
+	desc->bufsz = elem * szelem;
+	return (char*)desc + sizeof *desc;
+}
+
+void dynarr_free(void *da)
+{
+	if(da) {
+		free(DESC(da));
+	}
+}
+
+void *dynarr_resize(void *da, int elem)
+{
+	int newsz;
+	void *tmp;
+	struct arrdesc *desc;
+
+	if(!da) return 0;
+	desc = DESC(da);
+
+	newsz = desc->szelem * elem;
+
+	if(!(tmp = realloc(desc, newsz + sizeof *desc))) {
+		return 0;
+	}
+	desc = tmp;
+
+	desc->nelem = desc->max_elem = elem;
+	desc->bufsz = newsz;
+	return (char*)desc + sizeof *desc;
+}
+
+int dynarr_empty(void *da)
+{
+	return DESC(da)->nelem ? 0 : 1;
+}
+
+int dynarr_size(void *da)
+{
+	return DESC(da)->nelem;
+}
+
+
+/* stack semantics */
+void *dynarr_push(void *da, void *item)
+{
+	struct arrdesc *desc;
+	int nelem;
+
+	desc = DESC(da);
+	nelem = desc->nelem;
+
+	if(nelem >= desc->max_elem) {
+		/* need to resize */
+		struct arrdesc *tmp;
+		int newsz = desc->max_elem ? desc->max_elem * 2 : 1;
+
+		if(!(tmp = dynarr_resize(da, newsz))) {
+			fprintf(stderr, "failed to resize\n");
+			return da;
+		}
+		da = tmp;
+		desc = DESC(da);
+		desc->nelem = nelem;
+	}
+
+	memcpy((char*)da + desc->nelem++ * desc->szelem, item, desc->szelem);
+	return da;
+}
+
+void *dynarr_pop(void *da)
+{
+	struct arrdesc *desc;
+	int nelem;
+
+	desc = DESC(da);
+	nelem = desc->nelem;
+
+	if(!nelem) return da;
+
+	if(nelem <= desc->max_elem / 3) {
+		/* reclaim space */
+		struct arrdesc *tmp;
+		int newsz = desc->max_elem / 2;
+
+		if(!(tmp = dynarr_resize(da, newsz))) {
+			fprintf(stderr, "failed to resize\n");
+			return da;
+		}
+		da = tmp;
+		desc = DESC(da);
+		desc->nelem = nelem;
+	}
+	desc->nelem--;
+
+	return da;
+}
diff -r 8c6d64af9505 -r 38489ad82bf4 src/dynarr.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/dynarr.h	Sat Jan 14 08:10:50 2012 +0200
@@ -0,0 +1,16 @@
+#ifndef DYNARR_H_
+#define DYNARR_H_
+
+void *dynarr_alloc(int elem, int szelem);
+void dynarr_free(void *da);
+void *dynarr_resize(void *da, int elem);
+
+int dynarr_empty(void *da);
+int dynarr_size(void *da);
+
+/* stack semantics */
+void *dynarr_push(void *da, void *item);
+void *dynarr_pop(void *da);
+
+
+#endif	/* DYNARR_H_ */
diff -r 8c6d64af9505 -r 38489ad82bf4 src/mesh.c
--- a/src/mesh.c	Fri Jan 13 09:34:16 2012 +0200
+++ b/src/mesh.c	Sat Jan 14 08:10:50 2012 +0200
@@ -2,23 +2,53 @@
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
+#include <stdarg.h>
+#include <assert.h>
 #include "mesh.h"
+#include "dynarr.h"
 
-int mattr_init(struct mesh_attrib *ma)
+
+struct mesh_vertattr {
+	char *name;
+	void *data;
+	int elem_sz;
+};
+
+struct mesh_polyidx {
+	int *data;
+};
+
+struct mesh {
+	char *name;
+	int poly_nverts;	/* 3, 4, etc */
+
+	struct mesh_vertattr *attr;
+	struct mesh_polyidx *polyidx;
+};
+
+
+/* --- vertex attributes --- */
+
+int vattr_init(struct mesh_vertattr *ma, int elem_sz)
 {
-	memset(ma, 0, sizeof *ma);
+	ma->name = 0;
+	ma->elem_sz = elem_sz;
+
+	if(!(ma->data = dynarr_alloc(0, elem_sz))) {
+		return -1;
+	}
 	return 0;
 }
 
-void mattr_destroy(struct mesh_attrib *ma)
+void vattr_destroy(struct mesh_vertattr *ma)
 {
 	if(ma) {
 		free(ma->name);
-		free(ma->data);
+		dynarr_free(ma->data);
 	}
 }
 
-int mattr_set_name(struct mesh_attrib *ma, const char *name)
+int vattr_set_name(struct mesh_vertattr *ma, const char *name)
 {
 	char *tmp;
 
@@ -32,50 +62,71 @@
 	return 0;
 }
 
+const char *vattr_get_name(struct mesh_vertattr *ma)
+{
+	return ma->name ? ma->name : "<unnamed vattr>";
+}
+
 #define INITSZ	(16 * ma->elem_size)
-int mattr_add_elem(struct mesh_attrib *ma, void *data)
+int vattr_add_elem(struct mesh_vertattr *ma, void *elem)
 {
-	int nsz = (ma->count + 1) * ma->elem_size;
-
-	if(nsz > ma->datasz) {
-		void *tmp;
-
-		nsz = ma->datasz ? ma->datasz * 2 : INITSZ;
-
-		if(!(tmp = realloc(ma->data, nsz))) {
-			return -1;
-		}
-		ma->data = tmp;
-		ma->datasz = nsz;
+	void *tmp = dynarr_push(ma->data, elem);
+	if(!tmp) {
+		return -1;
 	}
-
-	memcpy((char*)ma->data + ma->elem_size * ma->count++, data, ma->elem_size);
+	ma->data = tmp;
 	return 0;
 }
 
+
+void *vattr_pointer(struct mesh_vertattr *ma)
+{
+	return ma->data;
+}
+
+int vattr_count(struct mesh_vertattr *ma)
+{
+	return dynarr_size(ma->data);
+}
+
+int vattr_elem_size(struct mesh_vertattr *ma)
+{
+	return ma->elem_sz;
+}
+
+
+
 /* -------- mesh -------- */
 
-int mesh_init(struct mesh *m)
+int mesh_init(struct mesh *m, int nverts)
 {
-	memset(m, 0, sizeof *m);
+	m->name = 0;
+	m->poly_nverts = nverts;
+
+	if(!(m->attr = dynarr_alloc(0, sizeof *m->attr))) {
+		return -1;
+	}
+
+	if(!(m->polyidx = dynarr_alloc(0, sizeof *m->polyidx))) {
+		dynarr_free(m->attr);
+		return -1;
+	}
 	return 0;
 }
 
 void mesh_destroy(struct mesh *m)
 {
-	int i;
+	int i, nattr = mesh_attr_count(m);
 
-	free(m->name);
+	for(i=0; i<nattr; i++) {
+		vattr_destroy(m->attr + i);
+	}
+	dynarr_free(m->attr);
 
-	for(i=0; i<m->num_attr; i++) {
-		mattr_destroy(&m->attr[i]);
+	for(i=0; i<nattr; i++) {
+		dynarr_free(m->polyidx[i].data);
 	}
-	free(m->attr);
-
-	for(i=0; i<m->num_attr; i++) {
-		free(m->polyidx[i]);
-	}
-	free(m->polyidx);
+	dynarr_free(m->polyidx);
 }
 
 int mesh_set_name(struct mesh *m, const char *name)
@@ -92,34 +143,84 @@
 	return 0;
 }
 
-int mesh_add_attrib(struct mesh *m, struct mesh_attrib *attr)
+const char *mesh_get_name(struct mesh *m)
 {
-	void *tmp;
-	int idx = m->num_attr++;
+	return m->name ? m->name : "<unnamed mesh>";
+}
 
-	if(!(tmp = realloc(m->attr, m->num_attr * sizeof *attr))) {
+int mesh_add_attrib(struct mesh *m, struct mesh_vertattr *attr)
+{
+	struct mesh_polyidx pidx;
+	void *tmp = dynarr_push(m->attr, attr);
+	if(!tmp) {
 		return -1;
 	}
 	m->attr = tmp;
-	m->attr[idx] = *attr;
 
-	if(!(tmp = realloc(m->polyidx, m->num_attr * sizeof *m->polyidx))) {
-		m->num_attr--;
+	if(!(pidx.data = dynarr_alloc(0, m->poly_nverts * sizeof *pidx.data))) {
+		assert(pidx.data);
 		return -1;
 	}
-	m->polyidx[idx] = 0;
 
+	tmp = dynarr_push(m->polyidx, &pidx);
+	if(!tmp) {
+		assert(tmp);
+		return -1;
+	}
+	m->polyidx = tmp;
 	return 0;
 }
 
 int mesh_find_attrib(struct mesh *m, const char *name)
 {
-	int i;
+	int i, nattr = mesh_attr_count(m);
 
-	for(i=0; i<m->num_attr; i++) {
-		if(strcmp(m->attr[i].name, name) == 0) {
+	for(i=0; i<nattr; i++) {
+		if(m->attr[i].name && strcmp(m->attr[i].name, name) == 0) {
 			return i;
 		}
 	}
 	return -1;
 }
+
+int mesh_attr_count(struct mesh *m)
+{
+	return dynarr_size(m->attr);
+}
+
+int mesh_poly_count(struct mesh *m)
+{
+	int i, nattr = mesh_attr_count(m);
+
+	for(i=0; i<nattr; i++) {
+		int count = dynarr_empty(m->polyidx[i].data);
+		if(count) {
+			return count;
+		}
+	}
+	return 0;
+}
+
+int mesh_add_polyref(struct mesh *m, int attr_loc, ...)
+{
+	int i, nattr = mesh_attr_count(m);
+	int *poly = alloca(m->poly_nverts * sizeof *poly);
+	va_list ap;
+	void *tmp;
+
+	if(attr_loc < 0 || attr_loc >= nattr) {
+		return -1;
+	}
+
+	va_start(ap, attr_loc);
+	for(i=0; i<m->poly_nverts; i++) {
+		poly[i] = va_arg(ap, int);
+	}
+	va_end(ap);
+
+	if(!(tmp = dynarr_push(m->polyidx[attr_loc].data, poly))) {
+		return -1;
+	}
+	m->polyidx[attr_loc].data = tmp;
+	return 0;
+}
diff -r 8c6d64af9505 -r 38489ad82bf4 src/mesh.h
--- a/src/mesh.h	Fri Jan 13 09:34:16 2012 +0200
+++ b/src/mesh.h	Sat Jan 14 08:10:50 2012 +0200
@@ -1,42 +1,48 @@
 #ifndef MESH_H_
 #define MESH_H_
 
-struct mesh_attrib {
-	char *name;
-	int count, elem_size;
-	void *data;
-
-	int datasz;
-};
-
-struct mesh {
-	char *name;
-	int poly_nverts;	/* 3, 4, etc */
-
-	struct mesh_attrib *attr;
-	int num_attr;
-
-	int **polyidx;
-	int num_poly;
-};
+struct mesh_vertattr;
+struct mesh_polyidx;
+struct mesh;
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-int mattr_init(struct mesh_attrib *ma);
-void mattr_destroy(struct mesh_attrib *ma);
+/* --- vertex attributes --- */
 
-int mattr_set_name(struct mesh_attrib *ma, const char *name);
-int mattr_add_elem(struct mesh_attrib *ma, void *data);
+int vattr_init(struct mesh_vertattr *ma, int elem_sz);
+void vattr_destroy(struct mesh_vertattr *ma);
 
-int mesh_init(struct mesh *m);
+int vattr_set_name(struct mesh_vertattr *ma, const char *name);
+const char *vattr_get_name(struct mesh_vertattr *ma);
+
+int vattr_add_elem(struct mesh_vertattr *ma, void *elem);
+
+void *vattr_pointer(struct mesh_vertattr *ma);
+int vattr_count(struct mesh_vertattr *ma);
+int vattr_elem_size(struct mesh_vertattr *ma);
+
+/* --- mesh --- */
+
+int mesh_init(struct mesh *m, int nverts);
 void mesh_destroy(struct mesh *m);
 
 int mesh_set_name(struct mesh *m, const char *name);
-int mesh_add_attrib(struct mesh *m, struct mesh_attrib *attr);
+const char *mesh_get_name(struct mesh *m);
+
+int mesh_add_attrib(struct mesh *m, struct mesh_vertattr *attr);
 int mesh_find_attrib(struct mesh *m, const char *name);
 
+int mesh_attr_count(struct mesh *m);
+int mesh_poly_count(struct mesh *m);
+
+/* the variable arguments correspond to the N indices of the N-gon
+ * for this particular vertex attribute (attr_loc, retrieved by
+ * mesh_find_attrib)
+ */
+int mesh_add_polyref(struct mesh *m, int attr_loc, ...);
+
 #ifdef __cplusplus
 }
 #endif