feat: introduce camera interface

This commit is contained in:
Kevin J. 2024-10-08 19:43:14 +02:00
parent 5d19366642
commit 950fb4d353
10 changed files with 235 additions and 222 deletions

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@ -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)

72
camera.c Normal file
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@ -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;
}

7
dev.c
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@ -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);

32
include/camera.h Normal file
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@ -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

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

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@ -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 vbo; // buffer for vertices
unsigned int ebo; // buffer for indices
unsigned int nbo; // buffer for normals
unsigned int pvao; // array object for paths
unsigned int pbo; // buffer for paths
unsigned int vao;
unsigned int vbo; // vertices
unsigned int ebo; // indices
unsigned int nbo; // normals
};
struct model *load_model(const char *path);

View File

@ -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);

29
math.c
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@ -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;
}
}

148
object.c
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@ -6,96 +6,91 @@
#include <assimp/scene.h>
#include <assimp/postprocess.h>
struct model *load_model(const char *path) {
struct model *new_model = (struct model *) calloc(1, sizeof(struct model));
const struct aiScene *scene = aiImportFile(path, aiProcess_Triangulate);
static int load_vertices(struct model *m, struct aiMesh *ms) {
m->vertices_num = ms->mNumVertices;
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
for (int vertex_index = 0; vertex_index < mesh->mNumVertices; vertex_index++) {
struct aiVector3D *vertex = &(mesh->mVertices[vertex_index]);
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);
ret = load_vertices(nm, mesh);
if (ret < 0) {
free(nm);
aiReleaseImport(scene);
return NULL;
}
// 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);
ret = load_indices(nm, mesh);
if (ret < 0) {
free(nm->vertices);
free(nm);
aiReleaseImport(scene);
return NULL;
}
// 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);
ret = load_normals(nm, mesh);
if (ret < 0) {
free(nm->vertices);
free(nm->indices);
free(nm);
aiReleaseImport(scene);
return NULL;
}
}
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) {
if (obj->paths_num <= obj->paths_max) {
obj->paths = (float *) reallocarray(obj->paths, (obj->paths_num+1)*3, sizeof(float));
}
if (obj->paths == NULL) {
fprintf(stderr, "Error: failed allocating memory for paths of object\n");
return -1;
}
memcpy(obj->paths+(obj->paths_num*3), obj->position, 3*sizeof(float));
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;
return nm;
}
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);

149
rendlib.c
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@ -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;
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];
struct camera *ac;
// 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_sub(camera_pos, front_scalar, camera_pos);
glm_vec3_mul(front_scalar, ac->front, front_scalar);
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_add(camera_pos, front_scalar, camera_pos);
glm_vec3_mul(front_scalar, ac->front, front_scalar);
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);
vec3 camera_center;
glm_vec3_add(camera_pos, camera_front, camera_center);
glm_lookat(camera_pos, camera_center, camera_up, view);
glm_mat4_identity(projection);
glm_perspective(glm_rad(fov), (float) screen_viewport[2]/(float) screen_viewport[3], 0.01f, 100000.0f, projection);
int ret = bake_camera(ac);
if (ret < 0) {
fprintf(stderr, "--error: failed baking camera\n");
return;
}
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(projection_uniform, 1, GL_FALSE, (float *) projection);
glUniformMatrix4fv(view_uniform, 1, GL_FALSE, (float *) ac->view);
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_y = (float) (y - (screen_viewport[3]/2)) * camera_sensitivity;
float offset_x = (float) (x - (screen_viewport[2]/2)) * ac->sensitivity;
float offset_y = (float) (y - (screen_viewport[3]/2)) * ac->sensitivity;
camera_yaw += offset_x;
camera_pitch -= offset_y;
ac->yaw += offset_x;
ac->pitch -= offset_y;
// limit view rotation
if (camera_pitch < -89.9f) {
camera_pitch = -89.9f;
if (ac->pitch < -89.9f) {
ac->pitch = -89.9f;
}
if (camera_pitch > 89.9f) {
camera_pitch = 89.9f;
if (ac->pitch > 89.9f) {
ac->pitch = 89.9f;
}
vec3 view_direction = { cos(glm_rad(camera_yaw)) * cos(glm_rad(camera_pitch)),
sin(glm_rad(camera_pitch)),
sin(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(ac->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();