render OBJ files

src/main.c

@@ -6,6 +6,9 @@
 #include "mesh.h"
 #include "array.h"
 
+
+
+
 triangle_t* triangles_to_render = NULL;
 
 vec3_t camera_position = {0, 0, -5};
@@ -30,7 +33,9 @@ void setup(void) {
     );
 
     // load cube vertices into mesh data
-    load_cube_mesh_data();
+//    load_obj_file_data("../assets/cube.obj");
+    load_obj_file_data("../assets/teapot.obj");
+//    load_cube_mesh_data();
 }
 
 void process_input(void) {
@@ -71,9 +76,9 @@ void update(void) {
     //initialize array of triangles
     triangles_to_render = NULL;
 
-    mesh.rotation.y += 0.01f;
+    mesh.rotation.x += .01f;
-    mesh.rotation.z += 0.01f;
+    mesh.rotation.y += .01f;
-    mesh.rotation.x += 0.01f;
+    mesh.rotation.z += .01f;
 
     int num_faces = array_length(mesh.faces);
     for (int i = 0; i < num_faces; i++) {

src/mesh.c

@@ -1,6 +1,9 @@
 #include <stdio.h>
+#include <string.h>
+#include <stdbool.h>
 #include "mesh.h"
 #include "array.h"
+#include <stdlib.h>
 
 mesh_t mesh = {
         .vertices = NULL,
@@ -40,6 +43,7 @@ face_t cube_faces[N_CUBE_FACES] = {
         {.a = 6, .b = 1, .c = 4},
 };
 
+
 void load_cube_mesh_data(void) {
     for (int i = 0; i < N_CUBE_VERTICES; i++){
         vec3_t cube_vertex = cube_vertices[i];
@@ -49,4 +53,56 @@ void load_cube_mesh_data(void) {
         face_t cube_face = cube_faces[i];
         array_push(mesh.faces, cube_face);
     }
-}
+}
+
+void load_obj_file_data(char* filename) {
+    // load file to variable
+    char* obj = load_file(filename);
+    char* ch = NULL;
+    ch = strtok(obj, "\n");
+    while (ch != NULL)
+    {
+        if (strncmp("v ", ch, 2) == 0) {
+            printf("[%s]\n", ch);
+            vec3_t vertex;
+            sscanf(ch, "v %f %f %f", &vertex.x, &vertex.y, &vertex.z);
+            array_push(mesh.vertices, vertex);
+        } else if (strncmp("f ", ch, 2) == 0) {
+            int vertex_indices[3];
+            int textures_indices[3];
+            int normals_indices[3];
+            sscanf(ch, "f %d/%d/%d %d/%d/%d %d/%d/%d",
+                   &vertex_indices[0], &textures_indices[0], &normals_indices[0],
+                   &vertex_indices[1], &textures_indices[1], &normals_indices[1],
+                   &vertex_indices[2], &textures_indices[2], &normals_indices[2]);
+            face_t face = {
+                    .a = vertex_indices[0],
+                    .b = vertex_indices[1],
+                    .c = vertex_indices[2]
+            };
+            array_push(mesh.faces, face);
+        }
+        ch = strtok(NULL, "\n");
+    }
+}
+
+char* load_file(char const* filename) {
+    char* buffer = 0;
+    long length;
+    FILE * f = fopen (filename, "rb"); //was "rb"
+
+    if (f) {
+      fseek (f, 0, SEEK_END);
+      length = ftell (f);
+      fseek (f, 0, SEEK_SET);
+      buffer = (char*)malloc ((length+1)*sizeof(char));
+      if (buffer)
+      {
+        fread (buffer, sizeof(char), length, f);
+      }
+      fclose (f);
+    }
+    buffer[length] = '\0';
+    return buffer;
+}
+

src/mesh.h

@@ -16,5 +16,6 @@ typedef struct {
 
 extern mesh_t mesh;
 void load_cube_mesh_data(void);
-
+void load_obj_file_data(char* filename);
+char* load_file(const char* filename);
 #endif //RENDERER_MESH_H