feat: introduce camera interface

Makefile

@@ -10,7 +10,8 @@ all:
 	$(CC) $(CFLAGS) -c rendlib.c -o $(OUT)/rendlib.o $(LFLAGS)
 	$(CC) $(CFLAGS) -c math.c -o $(OUT)/math.o $(LFLAGS)
 	$(CC) $(CFLAGS) -c object.c -o $(OUT)/object.o $(LFLAGS)
-	$(LD) -relocatable $(OUT)/rendlib.o $(OUT)/math.o $(OUT)/object.o -o $(OUT)/rendlib
+	$(CC) $(CFLAGS) -c camera.c -o $(OUT)/camera.o $(LFLAGS)
+	$(LD) -relocatable $(OUT)/rendlib.o $(OUT)/math.o $(OUT)/object.o $(OUT)/camera.o -o $(OUT)/rendlib
 
 dev: all
 	$(CC) $(CFLAGS) dev.c $(OUT)/rendlib -o $(OUT)/dev $(LFLAGS)

camera.c

@@ -0,0 +1,72 @@
+#include <string.h>
+#include <cglm/cam.h>
+#include <GL/glew.h>
+#include "include/camera.h"
+
+struct camera *create_camera(int type) {
+    if (type != CAMERA_PERSPECTIVE && 
+        type != CAMERA_ORTHOGONAL) {
+        return NULL;
+    }
+
+    struct camera *c = malloc(sizeof(struct camera));
+    if (c == NULL) {
+        return NULL;
+    }
+
+    memset(c, 0, sizeof(struct camera));
+
+    c->type = type;
+    c->fov = 80.0f;
+    c->near_z = 0.01f; 
+    c->far_z = 1000.0f;
+    c->yaw = -90.0f;
+    c->pitch = 0.0f;
+    c->sensitivity = 0.02f;
+
+    if (c->type == CAMERA_ORTHOGONAL) {
+        c->viewport_modifier = 0.5f;
+    }
+
+    c->pos[0] = 0.0f;
+    c->pos[1] = 0.0f;
+    c->pos[2] = 10.0f;
+
+    c->front[0] = 0.0f;
+    c->front[1] = 0.0f;
+    c->front[2] = -1.0f;
+    
+    c->up[0] = 0.0f;
+    c->up[1] = 1.0f;
+    c->up[2] = 0.0f;
+
+    return c;
+}
+
+int bake_camera(struct camera *c) {
+    glm_mat4_identity(c->view);
+    glm_vec3_add(c->pos, c->front, c->center);
+    glm_lookat(c->pos, c->center, c->up, c->view);
+
+    glm_mat4_identity(c->projection);
+
+    int screen_viewport[4]; 
+    glGetIntegerv(GL_VIEWPORT, screen_viewport);
+    if (c->type == CAMERA_PERSPECTIVE) {
+        glm_perspective(glm_rad(c->fov), 
+                (float) ((float)screen_viewport[2]/(float)screen_viewport[3]), 
+                c->near_z, c->far_z,
+                c->projection);
+    } else if (c->type == CAMERA_ORTHOGONAL) {
+        float left = -screen_viewport[2]/2    * c->viewport_modifier; 
+        float right = screen_viewport[2]/2    * c->viewport_modifier;
+        float top = screen_viewport[3]/2      * c->viewport_modifier;
+        float bottom = -screen_viewport[3]/2  * c->viewport_modifier;
+        glm_ortho(left, right, bottom, top, c->near_z, c->far_z, c->projection);
+    } else {
+        return -1;
+    }
+
+    return 0;
+}
+

dev.c

@@ -1,6 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include "include/rendlib.h"
+#include "include/camera.h"
 #include "include/object.h"
 
 int main(int argc, char *argv[]) {
@@ -22,6 +23,12 @@ int main(int argc, char *argv[]) {
         return EXIT_FAILURE;
     }
 
+    struct camera *c = create_camera(CAMERA_PERSPECTIVE);
+    if (c == NULL) {
+        fprintf(stderr, "--error: creating camera\n");
+        return EXIT_FAILURE;
+    }
+
     ret = rendlib_render();
     if (ret < 0) {
         fprintf(stderr, "--error: %d\n", ret);

include/camera.h

@@ -0,0 +1,32 @@
+#ifndef CAMERA_H
+#define CAMERA_H
+
+#include <cglm/vec3.h>
+#include <cglm/mat4.h>
+
+#define CAMERA_PERSPECTIVE 0x1
+#define CAMERA_ORTHOGONAL 0x2
+
+struct camera {
+    int type;
+    float fov; 
+    float near_z; 
+    float far_z; 
+    float yaw; 
+    float pitch; 
+    float sensitivity; 
+    float viewport_modifier;
+
+    vec3 pos; 
+    vec3 front;
+    vec3 center;
+    vec3 up; 
+
+    mat4 view; 
+    mat4 projection;
+};
+
+struct camera *create_camera(int type);
+int bake_camera(struct camera *c);
+
+#endif 

include/math.h

@@ -5,6 +5,5 @@
 #include <cglm/cglm.h>
 
 float frand48(void);
-void calculate_gravity(struct object *src, struct object *target, vec3 force);
 
 #endif 

include/object.h

@@ -22,20 +22,13 @@ struct object {
     float mass;
     void *next;
 
-    float *paths;
-    int paths_num;
-    int paths_max;
-
     struct model *model;
     float scale;
 
-    unsigned int vao; // array object for the actual object
+    unsigned int vao; 
-    unsigned int vbo; // buffer for vertices
+    unsigned int vbo; // vertices
-    unsigned int ebo; // buffer for indices
+    unsigned int ebo; // indices
-    unsigned int nbo; // buffer for normals
+    unsigned int nbo; // normals
-
-    unsigned int pvao; // array object for paths
-    unsigned int pbo; // buffer for paths
 };
 
 struct model *load_model(const char *path);

include/rendlib.h

@@ -15,6 +15,7 @@ enum errs {
     err_shaders_init = -4,
 };
 
+extern struct camera *active_camera;
 extern struct object *objects;
 int rendlib_start_window(int argc, char *argv[]);
 int rendlib_render(void);

math.c

@@ -11,32 +11,3 @@ float frand48(void) {
 
     return number;
 }
-
-void calculate_gravity(struct object *src, struct object *target, vec3 force) {
-    vec4 v4distance;
-    glm_vec4_sub(target->position, src->position, v4distance);
-
-    vec3 v3distance;
-    glm_vec3(v4distance, v3distance);
-
-    float distance_xy = sqrt((v3distance[0] * v3distance[0]) + (v3distance[1] * v3distance[1]));
-    float distance_xyz = sqrt((distance_xy * distance_xy) + (v3distance[2] * v3distance[2]));
-    float force_scale = 4.0f;
-
-    float g = 6.67f * 1e-11f;
-    float top = g * src->mass * target->mass;
-
-    for (int i = 0; i < 3; i++) {
-        v3distance[i] = (v3distance[i] * v3distance[i] * v3distance[i]);
-    }
-
-    for (int i = 0; i < 3; i++) {
-        if (v3distance[i] == 0) {
-            force[i] = 0.0f;
-            continue;
-        }
-
-        force[i] = (top / (distance_xyz / (target->position[i] - src->position[i]))) * force_scale;
-    }
-}
-

object.c

@@ -6,96 +6,91 @@
 #include <assimp/scene.h>
 #include <assimp/postprocess.h>
 
-struct model *load_model(const char *path) {
+static int load_vertices(struct model *m, struct aiMesh *ms) {
-    struct model *new_model = (struct model *) calloc(1, sizeof(struct model));
+    m->vertices_num = ms->mNumVertices;
-    const struct aiScene *scene = aiImportFile(path, aiProcess_Triangulate);
+    int len = m->vertices_num * sizeof(struct aiVector3D);
+    m->vertices = malloc(len);
+    if (m->vertices == NULL) {
+        return -1;
+    }
 
+    memset(m->vertices, 0, len);
+    memcpy(m->vertices, ms->mVertices, len);
+    return 0;
+}
+
+static int load_indices(struct model *m, struct aiMesh *ms) {
+    for (int face_index = 0; face_index < ms->mNumFaces; face_index++) {
+        struct aiFace *face = &(ms->mFaces[face_index]);
+        long start = m->indices_num;
+
+        m->indices_num += face->mNumIndices;
+        m->indices = (unsigned int *) realloc(m->indices, sizeof(unsigned int)*m->indices_num);
+        if (m->indices == NULL) {
+            return -1;
+        }
+
+        memcpy(&m->indices[start], face->mIndices, sizeof(unsigned int)*face->mNumIndices);
+    }
+    return 0;
+}
+
+static int load_normals(struct model *m, struct aiMesh *ms) {
+    m->normals_num = ms->mNumVertices;
+    int len = m->vertices_num * sizeof(struct aiVector3D); 
+    m->normals = malloc(len);
+    if (m->vertices == NULL) {
+        return -1;
+    }
+    memset(m->normals, 0, len);
+    memcpy(m->normals, ms->mNormals, len);
+    return 0;
+}
+
+struct model *load_model(const char *path) {
+    int ret = 0; 
+    struct model *nm = malloc(sizeof(struct model));
+    if (nm == NULL) {
+        return NULL;
+    }
+
+    memset(nm, 0, sizeof(struct model));
+
+    const struct aiScene *scene = aiImportFile(path, aiProcess_Triangulate);
     if (scene == NULL) {
-        fprintf(stderr, "Error: failed importing file from path '%s'", path);
+        free(nm);
+        return NULL;
     }
 
     for (int mesh_index = 0; mesh_index < scene->mNumMeshes; mesh_index++) {
         struct aiMesh *mesh = scene->mMeshes[mesh_index];
 
-        // fetch vertices
+        ret = load_vertices(nm, mesh);
-        for (int vertex_index = 0; vertex_index < mesh->mNumVertices; vertex_index++) {
+        if (ret < 0) {
-            struct aiVector3D *vertex = &(mesh->mVertices[vertex_index]);
+            free(nm);
-            long start = new_model->vertices_num*3;
-
-            new_model->vertices_num++;
-            new_model->vertices = (float *) realloc(new_model->vertices, new_model->vertices_num*3*sizeof(float));
-            if (new_model->vertices == NULL) {
-                fprintf(stderr, "Error: failed allocating memory for vertices\n");
-                goto error;
-            }
-
-            memcpy(&new_model->vertices[start], vertex, sizeof(float)*3);
-        }
-
-        // fetch indices
-        for (int face_index = 0; face_index < mesh->mNumFaces; face_index++) {
-            struct aiFace *face = &(mesh->mFaces[face_index]);
-            long start = new_model->indices_num;
-
-            new_model->indices_num += face->mNumIndices;
-            new_model->indices = (unsigned int *) realloc(new_model->indices, sizeof(unsigned int)*new_model->indices_num);
-            if (new_model->indices == NULL) {
-                fprintf(stderr, "Error: failed allocating memory for indices\n");
-                goto error;
-            }
-
-            memcpy(&new_model->indices[start], face->mIndices, sizeof(unsigned int)*face->mNumIndices);
-        }
-
-        // fetch normals
-        for (int normal_index = 0; normal_index < mesh->mNumVertices; normal_index++) {
-            struct aiVector3D *normal = &(mesh->mNormals[normal_index]);
-            long start = new_model->normals_num*3;
-
-            new_model->normals_num++;
-            new_model->normals = (float *) realloc(new_model->normals, new_model->normals_num*3*sizeof(float));
-            if (new_model->normals == NULL) {
-                fprintf(stderr, "Error: failed allocating memory for normals\n");
-                goto error;
-            }
-
-            memcpy(&new_model->normals[start], normal, sizeof(float)*3);
-        }
-    }
-
-    return new_model;
-
-error:
             aiReleaseImport(scene);
-    free(new_model->vertices);
-    free(new_model->indices);
-    free(new_model->normals);
-    free(new_model);
             return NULL;
         }
 
-int record_path(struct object *obj) {
+        ret = load_indices(nm, mesh);
-    if (obj->paths_num <= obj->paths_max) {
+        if (ret < 0) {
-        obj->paths = (float *) reallocarray(obj->paths, (obj->paths_num+1)*3, sizeof(float));
+            free(nm->vertices);
+            free(nm);
+            aiReleaseImport(scene);
+            return NULL;
         }
 
-    if (obj->paths == NULL) {
+        ret = load_normals(nm, mesh);
-        fprintf(stderr, "Error: failed allocating memory for paths of object\n");
+        if (ret < 0) {
-        return -1;
+            free(nm->vertices);
+            free(nm->indices);
+            free(nm);
+            aiReleaseImport(scene);
+            return NULL;
+        }
     }
 
-    memcpy(obj->paths+(obj->paths_num*3), obj->position, 3*sizeof(float));
+    return nm;
-
-    if (obj->paths_num < obj->paths_max) {
-        obj->paths_num++;
-        goto end;
-    }
-
-    // pop first element 
-    memmove(obj->paths, &obj->paths[3], (obj->paths_num)*3*sizeof(float));
-
-end:
-    return 0;
 }
 
 struct object *create_object(struct object **o, float mass, struct model *model) {
@@ -107,7 +102,6 @@ struct object *create_object(struct object **o, float mass, struct model *model)
 
     no->mass = mass;
     no->scale = 1.0f;
-    no->paths_max = MAX_PATHS;
     no->model = model;
     glm_vec4_one(no->position);
     glm_vec3_one(no->color);

rendlib.c

@@ -6,7 +6,7 @@
 #include <GLFW/glfw3.h>
 #include <cglm/cglm.h>
 #include "include/rendlib.h"
-#include "include/math.h"
+#include "include/camera.h"
 #include "include/object.h"
 
 // global variables 
@@ -14,31 +14,19 @@ int window_width = 960;
 int window_height = 540;
 char *window_title = "rendlib window";
 
-float fov = 90.0f;
+struct camera *ac;
-float camera_yaw = -90.0f;
-float camera_pitch = 0.0f;
-float camera_sensitivity = 0.02f;
-float top_movement_speed = 0.2f;
-vec3 camera_pos = { 0.0f, 0.0f, 50.0f };
-vec3 camera_front = { 0.0f, 0.0f, -1.0f };
-vec3 camera_up = { 0.0f, 1.0f, 0.0f }; 
-vec3 speed = { 0.0f, 0.0f, 0.0f };
-struct object *camera_lock = NULL;
-GLint screen_viewport[4];
 
-// tmp input 
+float top_movement_speed = 0.4f;
+vec3 speed = { 0.0f, 0.0f, 0.0f };
+GLint screen_viewport[4];
 char input = 0;
 
-// tmp 
-struct model *sphere_model;
 struct object *objects;
 
-// opengl
 unsigned int shader_program;
 unsigned int vertex_shader;
 unsigned int fragment_shader;
 
-// shaders
 const char *object_vertex_shader_location = "assets/shaders/shader.vert";
 const char *object_fragment_shader_location = "assets/shaders/shader.frag";
 
@@ -103,7 +91,6 @@ int load_shaders(void) {
     glDeleteProgram(shader_program);
     shader_program = glCreateProgram();
 
-    // create and load new shaders
     vertex_shader = glCreateShader(GL_VERTEX_SHADER);
     fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
 
@@ -115,7 +102,6 @@ int load_shaders(void) {
         return -1;
     }
 
-    // compile object shader program
     glAttachShader(shader_program, vertex_shader);
     glAttachShader(shader_program, fragment_shader);
     glLinkProgram(shader_program);
@@ -159,31 +145,31 @@ void handle_input(void) {
     if (input & RENDLIB_INPUT_LEFT) {
         vec3 side_scalar = {top_movement_speed, top_movement_speed, top_movement_speed };
         vec3 camera_side;
-        glm_cross(camera_front, camera_up, camera_side);
+        glm_cross(ac->front, ac->up, camera_side);
         glm_normalize(camera_side);
         glm_vec3_mul(camera_side, side_scalar, camera_side);
-        glm_vec3_sub(camera_pos, camera_side, camera_pos);
+        glm_vec3_sub(ac->pos, camera_side, ac->pos);
     }
 
     if (input & RENDLIB_INPUT_RIGHT) {
         vec3 side_scalar = {top_movement_speed, top_movement_speed, top_movement_speed };
         vec3 camera_side;
-        glm_cross(camera_front, camera_up, camera_side);
+        glm_cross(ac->front, ac->up, camera_side);
         glm_normalize(camera_side);
         glm_vec3_mul(camera_side, side_scalar, camera_side);
-        glm_vec3_add(camera_pos, camera_side, camera_pos);
+        glm_vec3_add(ac->pos, camera_side, ac->pos);
     }
 
     if (input & RENDLIB_INPUT_BACKW) {
         vec3 front_scalar = {top_movement_speed, top_movement_speed, top_movement_speed };
-        glm_vec3_mul(front_scalar, camera_front, front_scalar);
+        glm_vec3_mul(front_scalar, ac->front, front_scalar);
-        glm_vec3_sub(camera_pos, front_scalar, camera_pos);
+        glm_vec3_sub(ac->pos, front_scalar, ac->pos);
     }
 
     if (input & RENDLIB_INPUT_FORW) {
         vec3 front_scalar = {top_movement_speed, top_movement_speed, top_movement_speed };
-        glm_vec3_mul(front_scalar, camera_front, front_scalar);
+        glm_vec3_mul(front_scalar, ac->front, front_scalar);
-        glm_vec3_add(camera_pos, front_scalar, camera_pos);
+        glm_vec3_add(ac->pos, front_scalar, ac->pos);
     }
 }
 
@@ -195,9 +181,6 @@ void display(void) {
     handle_input();
     GLFWwindow *w = glfwGetCurrentContext();
 
-    mat4 view;
-    mat4 projection;
-
     GLint translation_uniform;
     GLint view_uniform;
     GLint projection_uniform;
@@ -208,13 +191,11 @@ void display(void) {
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
     glUseProgram(shader_program);
 
-    glm_mat4_identity(view);
+    int ret = bake_camera(ac);
-    vec3 camera_center;
+    if (ret < 0) {
-    glm_vec3_add(camera_pos, camera_front, camera_center);
+        fprintf(stderr, "--error: failed baking camera\n");
-    glm_lookat(camera_pos, camera_center, camera_up, view);
+        return;
-
+    }
-    glm_mat4_identity(projection);
-    glm_perspective(glm_rad(fov), (float) screen_viewport[2]/(float) screen_viewport[3], 0.01f, 100000.0f, projection);
 
     view_uniform = glGetUniformLocation(shader_program, "view");
     projection_uniform = glGetUniformLocation(shader_program, "projection");
@@ -222,44 +203,14 @@ void display(void) {
     color_uniform = glGetUniformLocation(shader_program, "color");
     scale_uniform = glGetUniformLocation(shader_program, "scale");
 
-    glUniformMatrix4fv(view_uniform, 1, GL_FALSE, (float *) view);
+    glUniformMatrix4fv(view_uniform, 1, GL_FALSE, (float *) ac->view);
-    glUniformMatrix4fv(projection_uniform, 1, GL_FALSE, (float *) projection);
+    glUniformMatrix4fv(projection_uniform, 1, GL_FALSE, (float *) ac->projection);
 
     for (struct object *obj = objects; obj != NULL; obj = obj->next) {
         mat4 translation_matrix;
         glm_mat4_identity(translation_matrix);
+
         struct model *obj_model = obj->model;
-
-        // calculate gravity
-        for (struct object *target = objects; target != NULL; target = target->next) {
-            if (target == obj) {
-                continue;
-            }
-
-            vec3 force;
-            glm_vec3_zero(force);
-            calculate_gravity(obj, target, force);
-
-            vec4 force_new;
-            for (int i = 0; i < 3; i++) {
-                force_new[i] = force[i];
-            }
-            force_new[3] = 0.0f;
-
-            float n = obj->mass;
-            vec4 scaler = {n,n,n,1.0f};
-            glm_vec4_div(force_new, scaler, force_new);
-
-            glm_vec4_add(force_new, obj->translation_force, obj->translation_force);
-        }
-
-        glm_vec4_add(obj->position, obj->translation_force, obj->position);
-
-        // follow object if camera locked 
-        if (camera_lock == obj) {
-            glm_vec3_add(camera_pos, obj->translation_force, camera_pos);
-        }
-
         glm_translate(translation_matrix, obj->position);
 
         glUniformMatrix4fv(translation_uniform, 1, GL_FALSE, (float *) translation_matrix);
@@ -269,41 +220,21 @@ void display(void) {
 
         glBindVertexArray(obj->vao);
         glDrawElements(GL_TRIANGLES, obj_model->indices_num, GL_UNSIGNED_INT, (void *) 0);
-
-        glBindVertexArray(obj->pvao);
-
-        glBindBuffer(GL_ARRAY_BUFFER, obj->pbo);
-        glBufferData(GL_ARRAY_BUFFER, obj->paths_num*3*sizeof(float),obj->paths, GL_STATIC_DRAW);
-
-        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3*sizeof(float), (void *) 0);
-        glEnableVertexAttribArray(0);
-
-        glm_mat4_identity(translation_matrix);
-        glUniformMatrix4fv(translation_uniform, 1, GL_FALSE, (float *) translation_matrix);
-        glUniform1f(scale_uniform, 1.0f);
-
-        glDrawArrays(GL_LINE_STRIP, 0, obj->paths_num);
     }
 
-    /*glutPostRedisplay();
-    glutSwapBuffers();*/
     glfwSwapBuffers(w);
     glfwPollEvents();
 }
 
 void rendlib_bake_graphics(void) {
-    // setup default mouse position
     glGetIntegerv(GL_VIEWPORT, screen_viewport);
 
-
     for (struct object *obj = objects; obj != NULL; obj = obj->next) {
         struct model *obj_model = obj->model;
         glGenVertexArrays(1, &obj->vao);
-        glGenVertexArrays(1, &obj->pvao);
         glGenBuffers(1, &obj->vbo);
         glGenBuffers(1, &obj->ebo);
         glGenBuffers(1, &obj->nbo);
-        glGenBuffers(1, &obj->pbo);
 
         glBindVertexArray(obj->vao);
 
@@ -406,25 +337,24 @@ void mouse_motion(GLFWwindow *window, double x, double y) {
         return;
     }
 
-    float offset_x = (float) (x - (screen_viewport[2]/2)) * camera_sensitivity;
+    float offset_x = (float) (x - (screen_viewport[2]/2)) * ac->sensitivity;
-    float offset_y = (float) (y - (screen_viewport[3]/2)) * camera_sensitivity;
+    float offset_y = (float) (y - (screen_viewport[3]/2)) * ac->sensitivity;
 
-    camera_yaw += offset_x;
+    ac->yaw += offset_x;
-    camera_pitch -= offset_y;
+    ac->pitch -= offset_y;
 
-    // limit view rotation
+    if (ac->pitch < -89.9f) {
-    if (camera_pitch < -89.9f) {
+        ac->pitch = -89.9f;
-        camera_pitch = -89.9f;
     }
-    if (camera_pitch > 89.9f) {
+    if (ac->pitch > 89.9f) {
-        camera_pitch = 89.9f;
+        ac->pitch = 89.9f;
     }
 
-    vec3 view_direction = { cos(glm_rad(camera_yaw)) * cos(glm_rad(camera_pitch)),
+    vec3 view_direction = { cos(glm_rad(ac->yaw)) * cos(glm_rad(ac->pitch)),
-	sin(glm_rad(camera_pitch)),
+	sin(glm_rad(ac->pitch)),
-	sin(glm_rad(camera_yaw)) * cos(glm_rad(camera_pitch))
+	sin(glm_rad(ac->yaw)) * cos(glm_rad(ac->pitch))
     };
-    glm_normalize_to(view_direction, camera_front);
+    glm_normalize_to(view_direction, ac->front);
 }
 
 int rendlib_start_window(int argc, char *argv[]) {
@@ -457,7 +387,20 @@ int rendlib_start_window(int argc, char *argv[]) {
     return 0;
 }
 
+int setup_default_camera(void) {
+    ac = create_camera(CAMERA_PERSPECTIVE);
+    if (ac == NULL) {
+        return -1;
+    }
+    return 0;
+}
+
 int rendlib_render(void) {
+    if (ac == NULL) {
+        if (setup_default_camera() < 0) {
+            return -1;
+        }
+    }
     rendlib_bake_graphics();
     for (;;) {
         display();