add model loading

1 files changed, 121 insertions, 0 deletions

diff --git a/src/model.c b/src/model.c
new file mode 100644
index 0000000..00837f7
--- /dev/null
+++ b/src/model.c
@@ -0,0 +1,121 @@
+#include "../include/model.h"
+
+static honey_mesh assimp_to_honey_mesh(struct aiMesh* mesh, struct aiScene* scene) {
+  unsigned int vertex_step = 6;
+  bool mesh_has_uvs = false;
+  unsigned int n_vertices = mesh->mNumVertices;
+  
+  if (mesh->mTextureCoords[0]) {
+    mesh_has_uvs = true;
+    vertex_step = 8;
+  }
+
+  float* vertices = malloc(sizeof(float) * vertex_step * n_vertices);
+  for (int i=0; i<n_vertices; i++) {
+    int j = i*vertex_step;
+    /* positions */
+    vertices[j+0] = mesh->mVertices[i].x;
+    vertices[j+1] = mesh->mVertices[i].y;
+    vertices[j+2] = mesh->mVertices[i].z;
+
+    /* normals */
+    vertices[j+3] = mesh->mNormals[i].x;
+    vertices[j+4] = mesh->mNormals[i].y;
+    vertices[j+5] = mesh->mNormals[i].z;
+
+    /* uvs? */
+    if (mesh_has_uvs) {
+      vertices[j+6] = mesh->mTextureCoords[0][i].x;
+      vertices[j+7] = mesh->mTextureCoords[0][i].y;
+    }
+  }
+
+  unsigned int n_indices = mesh->mNumFaces*3;
+  unsigned int* indices = malloc(sizeof(unsigned int) * n_indices);
+  for (int i=0; i<mesh->mNumFaces; i++) {
+    int j = 3*i;
+    struct aiFace face = mesh->mFaces[i];
+    indices[j+0] = face.mIndices[0];
+    indices[j+1] = face.mIndices[1];
+    indices[j+2] = face.mIndices[2];
+  }
+
+  honey_mesh result;
+
+  if (mesh_has_uvs) {
+    unsigned int n_attributes = 3;
+    unsigned int attribute_sizes[] = { 3, 3, 2 };
+    honey_mesh_new(&result,
+                   vertices, n_vertices,
+                   n_attributes, attribute_sizes,
+                   indices, n_indices);
+  }
+  else {
+    unsigned int n_attributes = 2;
+    unsigned int attribute_sizes[] = { 3, 3 };
+    honey_mesh_new(&result,
+                   vertices, n_vertices,
+                   n_attributes, attribute_sizes,
+                   indices, n_indices);
+  }
+
+  free(vertices);
+  free(indices);
+
+  return result;
+}
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+
+static void process_assimp_node(honey_model* model, struct aiNode* node, struct aiScene* scene) {
+  for (int i=0; i<node->mNumMeshes; i++) {
+    struct aiMesh* mesh = scene->mMeshes[node->mMeshes[i]];
+    model->meshes[model->n_meshes] = assimp_to_honey_mesh(mesh, scene);
+    model->n_meshes++;
+  }
+
+  for (int i=0; i<node->mNumChildren; i++) {
+    process_assimp_node(model, node->mChildren[i], scene);
+  }
+}
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+  
+honey_error honey_model_load(honey_model* model,
+                             char* path) {
+  model->n_meshes = 0;
+  
+  struct aiScene* scene = aiImportFile(path,
+                                             aiProcess_Triangulate |
+                                             aiProcess_FlipUVs);
+  if (scene == NULL) {
+    honey_error_set_string1(path);
+    return HONEY_FILE_READ_ERROR;
+  }
+
+  if (scene->mFlags & AI_SCENE_FLAGS_INCOMPLETE ||
+      scene->mRootNode == NULL) {
+    honey_error_set_string1(path);
+    return HONEY_MODEL_LOAD_ERROR;
+  }
+  
+  process_assimp_node(model, scene->mRootNode, scene);
+
+  return HONEY_OK;
+}
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+
+void honey_model_draw(honey_model* model, honey_shader shader) {
+  for (int i=0; i<model->n_meshes; i++) {
+    honey_mesh_draw(model->meshes[i], shader);
+  }
+}
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+
+void honey_model_delete(honey_model* model) {
+  for (int i=0; i<model->n_meshes; i++) {
+    honey_mesh_delete(model->meshes[i]);
+  }
+}