From 957c4b6f68436910e1c5cf9e718cf4d81bb88834 Mon Sep 17 00:00:00 2001 From: 0xdeadbeer <64986162+0xdeadbeer@users.noreply.github.com> Date: Sat, 21 Oct 2023 13:08:30 +0200 Subject: [PATCH] Physics: implement basic gravitational attraction --- assets/shaders/shader.frag | 17 ++-- assets/shaders/shader.vert | 5 +- main.c | 200 +++++++++++++++++++++++++++++-------- 3 files changed, 176 insertions(+), 46 deletions(-) diff --git a/assets/shaders/shader.frag b/assets/shaders/shader.frag index 43a223a..18facea 100644 --- a/assets/shaders/shader.frag +++ b/assets/shaders/shader.frag @@ -1,16 +1,21 @@ #version 330 core in vec4 frag_pos; in vec4 frag_normal; +in vec3 object_color; out vec4 output; void main() { - vec4 ambient = vec4(0.0, 0.2, 0.46, 1.0); + vec4 norm = normalize(frag_normal); + // vec4 ambient = vec4(0.0, 0.2, 0.46, 1.0); + vec4 light_color = vec4(0.7, 0.7, 0.7, 1.0); + vec4 color = vec4(object_color.xyz, 1.0f); - vec4 light_location = vec4(0.0, 5.0, 0.0, 0.0); - vec4 light_color = vec4(0.1, 0.1, 0.2, 1.0); - vec4 light_distance = frag_pos - light_location; - float inverted_dot = -dot(frag_normal.xyz, light_distance.xyz); + vec4 light_location = vec4(5.0, 5.0, -10.0, 0.0); + vec4 light_direction = normalize(light_location - frag_pos); + float diff = max(dot(norm.xyz, light_direction.xyz), 0.0); - output = ambient * light_color * inverted_dot; + vec4 diffuse = diff * light_color; + + output = color + diffuse; } \ No newline at end of file diff --git a/assets/shaders/shader.vert b/assets/shaders/shader.vert index 2b21210..884fd70 100644 --- a/assets/shaders/shader.vert +++ b/assets/shaders/shader.vert @@ -6,12 +6,15 @@ uniform mat4 view; uniform mat4 projection; uniform mat4 translation; uniform mat4 rotation; +uniform vec3 color; out vec4 frag_pos; out vec4 frag_normal; +out vec3 object_color; void main() { - gl_Position = projection * view * translation * rotation * vec4(pos.xyz, 1.0); + gl_Position = projection * view * translation * vec4(pos.xyz, 1.0); frag_pos = gl_Position; frag_normal = translation * vec4(normal.xyz, 1.0); + object_color = color; } \ No newline at end of file diff --git a/main.c b/main.c index 767068e..5825269 100644 --- a/main.c +++ b/main.c @@ -1,3 +1,4 @@ +#include #include #include #include @@ -8,10 +9,13 @@ #include #include -unsigned int vao; -unsigned int vbo; -unsigned int ebo; -unsigned int nbo; +float frand48(void) { + return (float) rand() / (float) (RAND_MAX + 1.0); +} + +float fov = 45.0f; // default fov +float fov_change = 1.0f; + unsigned int shader_program; unsigned int vertex_shader; unsigned int fragment_shader; @@ -20,27 +24,13 @@ unsigned int fragment_shader; const char *vertex_shader_location = "assets/shaders/shader.vert"; const char *fragment_shader_location = "assets/shaders/shader.frag"; -// GPU data -float *vertices = NULL; -unsigned int *indices = NULL; -float *normals = NULL; -long vertices_num = 0; -long indices_num = 0; -long normals_num = 0; - -// Camera / LookAt -vec3 camera_position; -vec3 world_origin; -vec3 up; -vec3 right; -vec3 forward; - // structs struct object { - mat4 rotation_matrix; - mat4 translation_matrix; - vec3 translation_force; - vec3 rotation_force; + vec4 translation_force; + vec4 rotation_force; + vec4 position; + vec4 rotation; + vec3 color; float mass; void *next; @@ -210,6 +200,47 @@ int load_shaders() { return 0; } +void calculate_gravity(struct object *src, struct object *target, vec3 force) { + vec4 tmp; + + glm_vec4_sub(target->position, src->position, tmp); + + vec3 distance; + glm_vec3(tmp, distance); + + float h1 = sqrt((distance[0] * distance[0]) + (distance[1] * distance[1])); + float h2 = sqrt((h1 * h1) + (distance[2] * distance[2])); + + float g = 6.67f * 1e-11f; + float top = g * src->mass * target->mass; + vec3 top_vec = {top, top, top}; + float mass_area = target->mass; + + for (int i = 0; i < 3; i++) { + distance[i] = (distance[i] * distance[i] * distance[i]); + + /*if (distance[i] > -0.1 && distance[i] < 0) { + distance[i] = -0.1f; + } + + if (distance[i] < 0.1 && distance[i] > 0) { + distance[i] = 0.1f; + }*/ + } + + for (int i = 0; i < 3; i++) { + if (distance[i] == 0) { + force[i] = 0.0f; + continue; + } + + //force[i] = mass_area * (top_vec[i] / (distance[i] + (1 / (target->mass / mass_area)))); + force[i] = (top_vec[i] / (h2 / (target->position[i] - src->position[i]))); + //force[i] = (top_vec[i] / distance[i]); + + } +} + void display() { mat4 view; mat4 projection; @@ -220,6 +251,7 @@ void display() { GLint rotation_uniform; GLint view_uniform; GLint projection_uniform; + GLint color_uniform; glClearColor(0.13f, 0.13f, 0.13f, 0.0f); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); @@ -230,7 +262,7 @@ void display() { glm_translate(view, view_translate); glm_mat4_identity(projection); - glm_perspective(glm_rad(45.0f), (float) viewport[2]/(float) viewport[3], 0.01f, 100.0f, projection); + glm_perspective(glm_rad(fov), (float) viewport[2]/(float) viewport[3], 0.01f, 10000.0f, projection); view_uniform = glGetUniformLocation(shader_program, "view"); projection_uniform = glGetUniformLocation(shader_program, "projection"); @@ -241,9 +273,38 @@ void display() { glUniformMatrix4fv(projection_uniform, 1, GL_FALSE, (float *) projection); for (struct object *obj = objects; obj != NULL; obj = obj->next) { - glm_translate(obj->translation_matrix, obj->translation_force); - glUniformMatrix4fv(translation_uniform, 1, GL_FALSE, (float *) obj->translation_matrix); - glUniformMatrix4fv(rotation_uniform, 1, GL_FALSE, (float *) obj->rotation_matrix); + mat4 translation_matrix; + glm_mat4_identity(translation_matrix); + + + // 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); + //glm_vec4_add(obj->position, *force, obj->position); + 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(force_new, obj->position, obj->position); + } + + glm_vec4_add(obj->position, obj->translation_force, obj->position); + glm_translate(translation_matrix, obj->position); + + glUniformMatrix4fv(translation_uniform, 1, GL_FALSE, (float *) translation_matrix); + glUniform3fv(color_uniform, 1, (float *) obj->color); glBindVertexArray(obj->vao); glDrawElements(GL_TRIANGLES, obj->indices_num, GL_UNSIGNED_INT, (void *) 0); @@ -275,6 +336,19 @@ void keyboard(unsigned char key, int x, int y) { } } +void mouse(int button, int state, int x, int y) { + switch (button) { + case 3: + fov -= fov_change; + break; + case 4: + fov += fov_change; + break; + default: + break; + } +} + void setup() { for (struct object *obj = objects; obj != NULL; obj = obj->next) { glGenVertexArrays(1, &obj->vao); @@ -307,6 +381,7 @@ void setup() { glEnable(GL_DEPTH_TEST); } + struct object *create_object(float mass, const char *model) { struct object *new_object = (struct object *) malloc(sizeof(struct object)); @@ -315,8 +390,10 @@ struct object *create_object(float mass, const char *model) { } new_object->mass = mass; - glm_mat4_identity(new_object->translation_matrix); - glm_mat4_identity(new_object->rotation_matrix); + glm_vec4_one(new_object->position); + glm_vec4_one(new_object->rotation); + glm_vec4_zero(new_object->translation_force); + glm_vec4_zero(new_object->rotation_force); new_object->vertices_num = 0; new_object->indices_num = 0; new_object->normals_num = 0; @@ -324,6 +401,13 @@ struct object *create_object(float mass, const char *model) { new_object->indices = NULL; new_object->normals = NULL; new_object->next = NULL; + glm_vec3_one(new_object->color); + + // choose random color + for (int i = 0; i < 3; i++) { + new_object->color[i] = frand48(); + fprintf(stdout, "New color part set: %f\n", new_object->color[i]); + } if (load_model_to_object(model, new_object) == -1) { return NULL; @@ -345,6 +429,8 @@ struct object *create_object(float mass, const char *model) { } int main(int argc, char **argv) { + srandom(time(NULL)); + glutInit(&argc, argv); glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE); glutCreateWindow("Simple Space Time Simulator"); @@ -357,6 +443,7 @@ int main(int argc, char **argv) { fprintf(stdout, "Status: using with GLEW %s\n", glewGetString(GLEW_VERSION)); glutKeyboardFunc(&keyboard); + glutMouseFunc(&mouse); glutDisplayFunc(&display); if (load_shaders() != 0) { @@ -365,20 +452,55 @@ int main(int argc, char **argv) { } // objects - struct object *sphere = create_object(10, "assets/models/sphere.obj"); - struct object *kub = create_object(10, "assets/models/kub.obj"); + /*for (int i = 0; i < 100; i++) { + struct object *planet = create_object(rand()%100, "assets/models/sphere.obj"); - vec4 sphere_translate = {-8.0f, 2.0f, -10.0f}; - glm_translate(sphere->translation_matrix, sphere_translate); + int x_limit = 50; + int y_limit = 50; + float random_x = (float) -x_limit+(rand() % (x_limit*2)); + float random_y = (float) -y_limit+(rand() % (y_limit*2)); - float force[] = {0.05f, -0.02f, 0.0f}; - glm_vec3_make(force, sphere->translation_force); + // give random force as well + vec3 initial_boost; + glm_vec3_zero(initial_boost); - vec4 kub_translate = {10.0f, -2.0f, -15.0f}; - glm_translate(kub->translation_matrix, kub_translate); + for (int j = 0; j < 3; j++) { + initial_boost[j] = 1/(rand() % 2); + } - vec3 kub_rotation_axis = {1.0f, 0.5f, 0.0f}; - glm_rotate(kub->rotation_matrix, glm_rad(45.0f), kub_rotation_axis); + vec4 planet_position = {random_x, random_y, (float) -1000.0f, 0.0f}; + glm_vec4_add(planet->position, planet_position, planet->position); + glm_vec3_add(planet->translation_force, initial_boost, planet->translation_force); + }*/ + float distance = -1000.0f; + struct object *a = create_object(1000000000.0f, "assets/models/sphere.obj"); + struct object *b = create_object(10000000.0f, "assets/models/sphere.obj"); +// struct object *c = create_object(1000000000.0f, "assets/models/sphere.obj"); + //struct object *d = create_object(10.0f, "assets/models/sphere.obj"); + + vec4 a_pos = {0.0f, 0.0f, distance, 0.0f}; + glm_vec4_add(a->position, a_pos, a->position); + + vec4 b_pos = {50.0f, -50.0f, distance, 0.0f}; + glm_vec4_add(b->position, b_pos, b->position); + +// vec4 c_pos = {0.0f, -20.0f, distance, 0.0f}; +// glm_vec4_add(c->position, c_pos, c->position); + + //vec4 d_pos = {0.0f, 20.0f, distance, 0.0f}; + //glm_vec4_add(d->position, d_pos, d->position); + + //struct object *cube = create_object(1000.0f, "assets/models/kub.obj"); + //vec4 cube_location = {-2.0f, 0.0f, -10.0f, 0.0f}; + //glm_vec4_add(cube->position, cube_location, cube->position); + + float n = 0.1f; + + //vec3 a_boost = {10*n, 0.0f, 0.0f}; + //glm_vec3_add(a->translation_force, a_boost, a->translation_force); + + vec3 b_boost = {-100*n, 0.0f, 0.0f}; + glm_vec3_add(b->translation_force, b_boost, b->translation_force); setup();