.obj loading

1 files changed, 219 insertions, 0 deletions

diff --git a/src/objload.c b/src/objload.c
new file mode 100644
index 0000000..7cc12ab
--- /dev/null
+++ b/src/objload.c
@@ -0,0 +1,219 @@
+#include <stdio.h>
+#include <stdlib.h>
+#define _BSD_SOURCE
+#include <string.h>
+
+#include "objload.h"
+
+// TODO: !! vert_idx, norm_idx and uv_idx currently
+//          must be present for all faces
+// TODO: face vertices is hard-coded to 3
+
+
+#define OBJ_CHECK(x) do {                       \
+        OBJRES res = x;                         \
+        if(res != OBJ_SUCCESS) return res;      \
+    } while(0)
+
+static OBJRES data_allocate(FILE *fp, objload_t *obj);
+static OBJRES data_load(FILE *fp, objload_t *obj);
+
+static OBJRES data_load_vert(char *line, float vertex[3]);
+static OBJRES data_load_norm(char *line, float normal[3]);
+static OBJRES data_load_uv(char *line, float uvcoord[2]);
+
+static OBJRES data_load_face(char *line, struct face face[3]);
+static OBJRES data_load_face_entry(char *entry, struct face *face);
+
+OBJRES obj_load(FILE *fp, objload_t *obj)
+{
+    fseek(fp, 0, SEEK_SET);
+    OBJ_CHECK(data_allocate(fp, obj));
+    
+    fseek(fp, 0, SEEK_SET);
+    OBJ_CHECK(data_load(fp, obj));
+    
+    return OBJ_SUCCESS;
+}
+
+void obj_free(objload_t obj)
+{
+    if(obj.nvert)  free(obj.vertices);
+    if(obj.nnorm)  free(obj.normals);
+    if(obj.nuv)    free(obj.uvcoord);
+    if(obj.nfaces) free(obj.faces);
+}
+
+OBJRES obj_transfer_raw(objload_t obj, struct obj_struct_metadata metadata, size_t *nvbo, void *vbo)
+{
+    if(vbo == NULL) {
+        *nvbo = obj.nfaces * 3;
+        return OBJ_SUCCESS;
+    }
+
+    for(size_t i = 0; i < *nvbo; i++)
+    {
+        if(metadata.exist_flag & OBJ_STRUCT_VERT_EXISTS) {
+            memcpy(vbo + metadata.vert_off,
+                   obj.vertices[obj.faces[i/3][i%3].vertidx -1],
+                   sizeof(*obj.vertices));
+        }
+        if(metadata.exist_flag & OBJ_STRUCT_NORM_EXISTS) {
+            memcpy(vbo + metadata.norm_off,
+                   obj.normals[obj.faces[i/3][i%3].normidx -1],
+                   sizeof(*obj.normals));
+        }
+        if(metadata.exist_flag & OBJ_STRUCT_UVTX_EXISTS) {
+            memcpy(vbo + metadata.uvtx_off,
+                   obj.uvcoord[obj.faces[i/3][i%3].uvidx -1],
+                   sizeof(*obj.uvcoord));
+        }
+        
+        vbo += metadata.full_sz;
+    }
+
+    return OBJ_SUCCESS;
+}
+
+static OBJRES data_allocate(FILE *fp, objload_t *obj)
+{
+    char line[256] = {0};
+    while(fgets(line, sizeof(line), fp))
+    {
+        // printf("%s\n", line);
+        switch(line[0]) {
+        case 'o':
+            break;
+        case 'v':
+            switch(line[1]) {
+            case ' ':
+                obj->nvert++;
+                break;
+            case 'n':
+                obj->nnorm++;
+                break;
+            case 't':
+                obj->nuv++;
+                break;
+            default:
+                return OBJ_LINE_UNKNOWN;
+            }
+            break;
+        case 'f':
+            obj->nfaces++;
+            break;
+        case 'l': case 'm':
+        case 's': case 'u':
+            break; // temporary
+            return OBJ_NOT_SUPPORTED_LINE;
+        case '#': case EOF:
+            break;
+        default:
+            return OBJ_LINE_UNKNOWN;
+        }
+    }
+
+    obj->vertices = calloc(obj->nvert, sizeof(*obj->vertices));
+    obj->normals  = calloc(obj->nnorm, sizeof(*obj->normals));
+    obj->uvcoord  = calloc(obj->nuv, sizeof(*obj->uvcoord));
+    obj->faces    = calloc(obj->nfaces, sizeof(*obj->faces));
+    
+    return OBJ_SUCCESS;
+}
+
+static OBJRES data_load(FILE *fp, objload_t *obj)
+{
+    size_t vert_idx = 0;
+    size_t norm_idx = 0;
+    size_t uv_idx   = 0;
+    size_t face_idx = 0;
+    
+    char line[256] = {0};
+    while(fgets(line, sizeof(line), fp))
+    {
+        switch(line[0]) {
+        case 'v':
+            switch(line[1]) {
+            case ' ':
+                data_load_vert(line, obj->vertices[vert_idx++]);
+                break;
+            case 'n':
+                data_load_norm(line, obj->normals[norm_idx++]);
+                break;
+            case 't':
+                data_load_uv(line, obj->uvcoord[uv_idx++]);
+                break;
+            default:
+                break;
+            }
+            break;
+        case 'f':
+            data_load_face(line, obj->faces[face_idx++]);
+            break;
+        case '#':
+            break;
+        default:
+            break;
+        }
+    }
+    
+    return OBJ_SUCCESS;
+}
+
+static OBJRES data_load_vert(char *line, float vertex[3])
+{
+    char *saveptr;
+    strtok_r(line, " ", &saveptr);
+
+    vertex[0] = strtof(strtok_r(NULL, " ", &saveptr), NULL);
+    vertex[1] = strtof(strtok_r(NULL, " ", &saveptr), NULL);
+    vertex[2] = strtof(strtok_r(NULL, " ", &saveptr), NULL);
+
+    return OBJ_SUCCESS;
+}
+
+static OBJRES data_load_norm(char *line, float normal[3])
+{
+    char *saveptr;
+    strtok_r(line, " ", &saveptr);
+
+    normal[0] = strtof(strtok_r(NULL, " ", &saveptr), NULL);
+    normal[1] = strtof(strtok_r(NULL, " ", &saveptr), NULL);
+    normal[2] = strtof(strtok_r(NULL, " ", &saveptr), NULL);
+
+    return OBJ_SUCCESS;
+}
+
+static OBJRES data_load_uv(char *line, float uvcoord[2])
+{
+    char *saveptr;
+    strtok_r(line, " ", &saveptr);
+
+    uvcoord[0] = strtof(strtok_r(NULL, " ", &saveptr), NULL);
+    uvcoord[1] = strtof(strtok_r(NULL, " ", &saveptr), NULL);
+
+    return OBJ_SUCCESS;
+}
+
+static OBJRES data_load_face(char *line, struct face face[3])
+{
+    char *saveptr;
+    strtok_r(line, " ", &saveptr);
+    
+    data_load_face_entry(strtok_r(NULL, " ", &saveptr), &face[0]);
+    data_load_face_entry(strtok_r(NULL, " ", &saveptr), &face[1]);
+    data_load_face_entry(strtok_r(NULL, " ", &saveptr), &face[2]);
+    
+    return OBJ_SUCCESS;
+}
+
+static OBJRES data_load_face_entry(char *entry, struct face *face)
+{
+     char *saveptr;
+     
+     face->vertidx = strtoull(strtok_r(entry, "/", &saveptr), NULL, 10);
+     face->uvidx   = strtoull(strtok_r(NULL,  "/", &saveptr), NULL, 10);
+     face->normidx = strtoull(strtok_r(NULL,  "/", &saveptr), NULL, 10);
+
+     return OBJ_SUCCESS;
+}