176 lines
3.4 KiB
C
176 lines
3.4 KiB
C
/* scene.c
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*
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* Definition of Scene-related functions.
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*
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* Eryn Wells <eryn@erynwells.me>
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*/
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#include <math.h>
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#include <stdlib.h>
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#include "scene.h"
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#include "texture.h"
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struct _ObjectList
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{
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Object *object;
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ObjectList *next;
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};
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static Color scene_trace_ray(Scene *scene, const Ray ray, const int depth);
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/*
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* scene_init --
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*
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* Initialize and return a new Scene. If the Scene could not be created, NULL is returned.
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*/
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Scene *
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scene_init()
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{
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Scene *new_scene = malloc(sizeof(Scene));
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if (!new_scene) {
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return NULL;
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}
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// Set some default values.
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new_scene->height = 0;
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new_scene->width = 0;
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new_scene->camera = camera_init();
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return new_scene;
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}
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/*
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* scene_destroy --
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*
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* Cleanup a Scene.
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*/
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void
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scene_destroy(Scene *scene)
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{
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if (scene == NULL) {
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return;
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}
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camera_destroy(scene->camera);
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free(scene);
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}
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/*
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* scene_load --
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*
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* Load a scene from a file into the given Scene object.
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*/
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void
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scene_load(Scene *scene, FILE *scene_file)
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{ }
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/*
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* scene_render --
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*
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* Render the given Scene.
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*/
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void
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scene_render(Scene *scene)
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{
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scene->pixels = malloc(sizeof(Color) * scene->height * scene->width);
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if (scene->pixels == NULL) {
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// TODO: Print an error.
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return;
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}
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scene->width = 640;
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scene->height = 480;
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float fov = 30.0;
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float aspect_ratio = scene->width / scene->height;
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float angle = tan(M_PI * 0.5 * fov / 180.0);
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float xx, yy;
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Ray primary_ray;
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Vector3 direction;
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for (int y = 0; y < scene->height; y++) {
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for (int x = 0; x < scene->width; x++) {
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// Compute (x, y) of ray direction.
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xx = (2 * ((x + 0.5) / scene->width) - 1) * angle * aspect_ratio;
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yy = (1 - 2 * ((y + 0.5) / scene->height)) * angle;
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// Assemble a ray and trace it.
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direction = vector_init(xx, yy, 1);
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primary_ray = ray_init(ZeroVector3, vector_normalize(direction));
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scene->pixels[y * scene->height + x] = scene_trace_ray(scene, primary_ray, 0);
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}
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}
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scene->is_rendered = 1;
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}
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/*
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* scene_add_object --
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*
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* Add an Object to the Scene.
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*/
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void
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scene_add_object(Scene *scene, Object *obj)
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{
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ObjectList *ol = malloc(sizeof(ObjectList));
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if (ol == NULL) {
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return;
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}
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ol->object = obj;
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ol->next = NULL;
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if (scene->objects == NULL) {
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scene->objects = ol;
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return;
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}
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ObjectList *ptr = scene->objects;
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while (ptr != NULL) {
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if (ptr->next == NULL) {
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ptr->next = ol;
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}
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ptr = ptr->next;
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}
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}
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/* static */ Color
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scene_trace_ray(Scene *scene, const Ray ray, const int depth)
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{
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Color out_color = {0, 0, 0};
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// Find intersections of this ray with objects in the scene.
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Object *intersected_obj = NULL;
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float *t = NULL;
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float nearest_t;
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int nints;
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ObjectList *ptr = scene->objects;
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while (ptr != NULL) {
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nints = object_does_intersect(ptr->object, ray, &t);
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for (int i = 0; i < nints; i++) {
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if (t[i] < nearest_t) {
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intersected_obj = ptr->object;
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nearest_t = t[i];
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}
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}
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ptr = ptr->next;
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}
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// If there was no intersection, return black.
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if (intersected_obj == NULL) {
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return out_color;
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}
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Texture *tex = object_get_texture(intersected_obj);
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return texture_get_color(tex);
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}
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