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-rw-r--r--libdimension/dimension/object.h26
-rw-r--r--libdimension/objects.c104
-rw-r--r--libdimension/raytrace.c9
3 files changed, 86 insertions, 53 deletions
diff --git a/libdimension/dimension/object.h b/libdimension/dimension/object.h
index 901b366..fefb061 100644
--- a/libdimension/dimension/object.h
+++ b/libdimension/dimension/object.h
@@ -25,12 +25,27 @@
#ifndef DIMENSION_OBJECT_H
#define DIMENSION_OBJECT_H
+/* A type to represent a ray-object intersection */
+typedef struct {
+ /* The ray and point which intersected */
+ dmnsn_line ray;
+ double t;
+
+ /* The texture at the intersection point */
+ const dmnsn_texture *texture;
+} dmnsn_intersection;
+
+dmnsn_intersection *dmnsn_new_intersection();
+void dmnsn_delete_intersection(dmnsn_intersection *intersection);
+
/* Forward-declare dmnsn_object */
typedef struct dmnsn_object dmnsn_object;
/* Object callback types */
-typedef dmnsn_array *dmnsn_object_intersections_fn(const dmnsn_object *object,
- dmnsn_line line);
+
+typedef dmnsn_intersection *
+dmnsn_object_intersection_fn(const dmnsn_object *object, dmnsn_line line);
+
typedef int dmnsn_object_inside_fn(const dmnsn_object *object,
dmnsn_vector point);
@@ -43,9 +58,9 @@ struct dmnsn_object {
dmnsn_matrix trans;
/* Callback functions */
- dmnsn_object_intersections_fn *intersections_fn;
- dmnsn_object_inside_fn *inside_fn;
- dmnsn_free_fn *free_fn;
+ dmnsn_object_intersection_fn *intersection_fn;
+ dmnsn_object_inside_fn *inside_fn;
+ dmnsn_free_fn *free_fn;
/* Generic pointer for object info */
void *ptr;
@@ -53,7 +68,6 @@ struct dmnsn_object {
/* Allocate a dummy object */
dmnsn_object *dmnsn_new_object();
-
/* Free an object */
void dmnsn_delete_object(dmnsn_object *object);
diff --git a/libdimension/objects.c b/libdimension/objects.c
index 32d3fdd..780c06b 100644
--- a/libdimension/objects.c
+++ b/libdimension/objects.c
@@ -27,8 +27,10 @@
*/
/* Sphere object callbacks */
-static dmnsn_array *dmnsn_sphere_intersections_fn(const dmnsn_object *sphere,
- dmnsn_line line);
+
+static dmnsn_intersection *
+dmnsn_sphere_intersection_fn(const dmnsn_object *sphere, dmnsn_line line);
+
static int dmnsn_sphere_inside_fn(const dmnsn_object *sphere,
dmnsn_vector point);
@@ -38,18 +40,18 @@ dmnsn_new_sphere()
{
dmnsn_object *sphere = dmnsn_new_object();
if (sphere) {
- sphere->intersections_fn = &dmnsn_sphere_intersections_fn;
- sphere->inside_fn = &dmnsn_sphere_inside_fn;
+ sphere->intersection_fn = &dmnsn_sphere_intersection_fn;
+ sphere->inside_fn = &dmnsn_sphere_inside_fn;
}
return sphere;
}
-/* Return a list of insersections of `line' with a sphere */
-static dmnsn_array *
-dmnsn_sphere_intersections_fn(const dmnsn_object *sphere, dmnsn_line line)
+/* Returns the closest intersection of `line' with `sphere' */
+static dmnsn_intersection *
+dmnsn_sphere_intersection_fn(const dmnsn_object *sphere, dmnsn_line line)
{
- double a, b, c, t[2];
- dmnsn_array *array = dmnsn_new_array(sizeof(double));
+ double a, b, c, t;
+ dmnsn_intersection *intersection = NULL;
/* Solve (x0 + nx*t)^2 + (y0 + ny*t)^2 + (z0 + nz*t)^2 == 1 */
@@ -58,13 +60,20 @@ dmnsn_sphere_intersections_fn(const dmnsn_object *sphere, dmnsn_line line)
c = line.x0.x*line.x0.x + line.x0.y*line.x0.y + line.x0.z*line.x0.z - 1.0;
if (b*b - 4.0*a*c >= 0) {
- t[0] = (-b + sqrt(b*b - 4.0*a*c))/(2*a);
- t[1] = (-b - sqrt(b*b - 4.0*a*c))/(2*a);
- dmnsn_array_set(array, 0, &t[0]);
- dmnsn_array_set(array, 1, &t[1]);
+ t = (-b - sqrt(b*b - 4.0*a*c))/(2*a);
+ if (t < 0.0) {
+ t = (-b + sqrt(b*b - 4.0*a*c))/(2*a);
+ }
+
+ if (t >= 0.0) {
+ intersection = dmnsn_new_intersection();
+ intersection->ray = line;
+ intersection->t = t;
+ intersection->texture = sphere->texture;
+ }
}
- return array;
+ return intersection;
}
/* Return whether a point is inside a sphere (x**2 + y**2 + z**2 < 1.0) */
@@ -79,8 +88,8 @@ dmnsn_sphere_inside_fn(const dmnsn_object *sphere, dmnsn_vector point)
*/
/* Cube callbacks */
-static dmnsn_array *dmnsn_cube_intersections_fn(const dmnsn_object *cube,
- dmnsn_line line);
+static dmnsn_intersection *dmnsn_cube_intersection_fn(const dmnsn_object *cube,
+ dmnsn_line line);
static int dmnsn_cube_inside_fn(const dmnsn_object *cube,
dmnsn_vector point);
@@ -90,71 +99,84 @@ dmnsn_new_cube()
{
dmnsn_object *cube = dmnsn_new_object();
if (cube) {
- cube->intersections_fn = &dmnsn_cube_intersections_fn;
+ cube->intersection_fn = &dmnsn_cube_intersection_fn;
cube->inside_fn = &dmnsn_cube_inside_fn;
}
return cube;
}
/* Intersections callback for a cube */
-static dmnsn_array *
-dmnsn_cube_intersections_fn(const dmnsn_object *cube, dmnsn_line line)
+static dmnsn_intersection *
+dmnsn_cube_intersection_fn(const dmnsn_object *cube, dmnsn_line line)
{
- double t;
+ double t = -1.0, t_temp;
dmnsn_vector p;
- dmnsn_array *array = dmnsn_new_array(sizeof(double));
+ dmnsn_intersection *intersection = NULL;
/* Six ray-plane intersection tests (x, y, z) = +/- 1.0 */
if (line.n.x != 0.0) {
/* x = -1.0 */
- t = (-1.0 - line.x0.x)/line.n.x;
- p = dmnsn_line_point(line, t);
- if (p.y >= -1.0 && p.y <= 1.0 && p.z >= -1.0 && p.z <= 1.0) {
- dmnsn_array_push(array, &t);
+ t_temp = (-1.0 - line.x0.x)/line.n.x;
+ p = dmnsn_line_point(line, t_temp);
+ if (p.y >= -1.0 && p.y <= 1.0 && p.z >= -1.0 && p.z <= 1.0
+ && t_temp >= 0.0 && (t < 0.0 || t_temp < t)) {
+ t = t_temp;
}
/* x = 1.0 */
- t = (1.0 - line.x0.x)/line.n.x;
+ t_temp = (1.0 - line.x0.x)/line.n.x;
p = dmnsn_line_point(line, t);
- if (p.y >= -1.0 && p.y <= 1.0 && p.z >= -1.0 && p.z <= 1.0) {
- dmnsn_array_push(array, &t);
+ if (p.y >= -1.0 && p.y <= 1.0 && p.z >= -1.0 && p.z <= 1.0
+ && t_temp >= 0.0 && (t < 0.0 || t_temp < t)) {
+ t = t_temp;
}
}
if (line.n.y != 0.0) {
/* y = -1.0 */
- t = (-1.0 - line.x0.y)/line.n.y;
+ t_temp = (-1.0 - line.x0.y)/line.n.y;
p = dmnsn_line_point(line, t);
- if (p.x >= -1.0 && p.x <= 1.0 && p.z >= -1.0 && p.z <= 1.0) {
- dmnsn_array_push(array, &t);
+ if (p.y >= -1.0 && p.y <= 1.0 && p.z >= -1.0 && p.z <= 1.0
+ && t_temp >= 0.0 && (t < 0.0 || t_temp < t)) {
+ t = t_temp;
}
/* y = 1.0 */
- t = (1.0 - line.x0.y)/line.n.y;
+ t_temp = (1.0 - line.x0.y)/line.n.y;
p = dmnsn_line_point(line, t);
- if (p.x >= -1.0 && p.x <= 1.0 && p.z >= -1.0 && p.z <= 1.0) {
- dmnsn_array_push(array, &t);
+ if (p.y >= -1.0 && p.y <= 1.0 && p.z >= -1.0 && p.z <= 1.0
+ && t_temp >= 0.0 && (t < 0.0 || t_temp < t)) {
+ t = t_temp;
}
}
if (line.n.z != 0.0) {
/* z = -1.0 */
- t = (-1.0 - line.x0.z)/line.n.z;
+ t_temp = (-1.0 - line.x0.z)/line.n.z;
p = dmnsn_line_point(line, t);
- if (p.x >= -1.0 && p.x <= 1.0 && p.y >= -1.0 && p.y <= 1.0) {
- dmnsn_array_push(array, &t);
+ if (p.y >= -1.0 && p.y <= 1.0 && p.z >= -1.0 && p.z <= 1.0
+ && t_temp >= 0.0 && (t < 0.0 || t_temp < t)) {
+ t = t_temp;
}
/* z = 1.0 */
- t = (1.0 - line.x0.z)/line.n.z;
+ t_temp = (1.0 - line.x0.z)/line.n.z;
p = dmnsn_line_point(line, t);
- if (p.x >= -1.0 && p.x <= 1.0 && p.y >= -1.0 && p.y <= 1.0) {
- dmnsn_array_push(array, &t);
+ if (p.y >= -1.0 && p.y <= 1.0 && p.z >= -1.0 && p.z <= 1.0
+ && t_temp >= 0.0 && (t < 0.0 || t_temp < t)) {
+ t = t_temp;
}
}
- return array;
+ if (t >= 0.0) {
+ intersection = dmnsn_new_intersection();
+ intersection->ray = line;
+ intersection->t = t;
+ intersection->texture = cube->texture;
+ }
+
+ return intersection;
}
/* Inside callback for a cube */
diff --git a/libdimension/raytrace.c b/libdimension/raytrace.c
index 03dcbab..75e857c 100644
--- a/libdimension/raytrace.c
+++ b/libdimension/raytrace.c
@@ -230,7 +230,7 @@ dmnsn_raytrace_shoot(dmnsn_scene *scene, dmnsn_color color,
{
dmnsn_line ray, ray_trans;
dmnsn_object *object;
- dmnsn_array *intersections;
+ dmnsn_intersection *intersection;
unsigned int i;
/* Get the ray corresponding to the (x,y)'th pixel */
@@ -243,14 +243,11 @@ dmnsn_raytrace_shoot(dmnsn_scene *scene, dmnsn_color color,
ray_trans = dmnsn_matrix_line_mul(object->trans, ray);
/* Test for intersections with objects */
- intersections = (*object->intersections_fn)(object, ray_trans);
+ intersection = (*object->intersection_fn)(object, ray_trans);
- if (dmnsn_array_size(intersections) > 0) {
+ if (intersection) {
color = dmnsn_color_from_XYZ(dmnsn_whitepoint);
}
-
- /* Delete the intersections array */
- dmnsn_delete_array(intersections);
}
return color;
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-04 21:15:41 +0000