From 510f1bac9b71ba240d30bb5bc5df6501e70fafc9 Mon Sep 17 00:00:00 2001
From: DrNuget <drnuget@outlook.com>
Date: Sun, 4 Jan 2026 22:12:24 +0200
Subject: Working 3D with .obj file loading

---
 src/object.c | 109 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100644 src/object.c

(limited to 'src/object.c')

diff --git a/src/object.c b/src/object.c
new file mode 100644
index 0000000..25d504f
--- /dev/null
+++ b/src/object.c
@@ -0,0 +1,109 @@
+#include "object.h"
+
+void createViewModel(ViewModel *model, int num_vertices, float *vert, int num_indices, unsigned int *indices)
+{
+	model->num_indices = num_indices;
+	
+	glGenVertexArrays(1, &model->VAO);
+	glBindVertexArray(model->VAO);
+
+	glGenBuffers(1, &model->VBO);
+	glBindBuffer(GL_ARRAY_BUFFER, model->VBO);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(float)*num_vertices*3, vert, GL_STATIC_DRAW);
+
+	glGenBuffers(1, &model->EBO);
+
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, model->EBO);
+	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(unsigned int)*num_indices, indices, GL_STATIC_DRAW);
+
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
+	glEnableVertexAttribArray(0);
+}
+
+void killViewModel(ViewModel *model)
+{
+	glDeleteVertexArrays(1, &model->VAO);
+	glDeleteBuffers(1, &model->VBO);
+	glDeleteBuffers(1, &model->EBO);
+}
+
+void bindViewModel(ViewModel *model)
+{
+	glBindVertexArray(model->VAO);
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, model->EBO);
+}
+
+ViewModel loadViewModel(const char* filename)
+{
+	const struct aiScene* scene = aiImportFile(filename,
+			aiProcess_CalcTangentSpace |
+			aiProcess_Triangulate |
+			aiProcess_JoinIdenticalVertices |
+			aiProcess_SortByPType);
+
+	struct aiMesh *mesh = scene->mMeshes[0];
+
+	unsigned int *indices = malloc(mesh->mNumFaces*3*sizeof(unsigned int));
+	int index = 0;
+	for (unsigned int i=0;i<mesh->mNumFaces;i++) {
+		memcpy(&indices[index], mesh->mFaces[i].mIndices, 3*sizeof(unsigned int));
+		index+=3;
+	}
+
+	ViewModel model;
+	createViewModel(&model, mesh->mNumVertices, (float*)mesh->mVertices, mesh->mNumFaces*3, indices);
+	free(indices);
+	return model;
+}
+
+void createObject(Object *obj, ViewModel *model)
+{
+	obj->model = model;
+	glm_mat4_identity(obj->transform);
+
+	glm_vec3_zero(obj->pos);
+	glm_vec3_one(obj->size);
+
+	obj->rotation.angle = 0.0f;
+	glm_vec3_zero(obj->rotation.direction);
+}
+
+void moveObject(Object *obj, vec3 pos)
+{
+	glm_vec3_copy(
+			pos,
+			obj->pos
+			);
+	updateObjectTransform(obj);
+}
+
+void scaleObject(Object *obj, vec3 scale)
+{
+	glm_scale(obj->transform, scale);
+	updateObjectTransform(obj);
+}
+
+void rotateObject(Object *obj, float angle, vec3 direction)
+{
+	obj->rotation.angle = angle;
+	glm_vec3_copy(
+			direction,
+			obj->rotation.direction
+			);
+	updateObjectTransform(obj);
+}
+
+inline void updateObjectTransform(Object *obj)
+{
+	glm_mat4_identity(obj->transform);
+	glm_translate(obj->transform, obj->pos);
+	glm_rotate(obj->transform, obj->rotation.angle, obj->rotation.direction);
+	glm_scale(obj->transform, obj->size);
+}
+
+void drawObject(Game *game, Object *obj)
+{
+	glUniformMatrix4fv(game->transform_loc, 1, GL_FALSE, (float*)obj->transform);
+
+	glDrawElements(GL_TRIANGLES, obj->model->num_indices, GL_UNSIGNED_INT, 0);
+}
-- 
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