.gitignore

@@ -1,4 +1,5 @@
 *.bmp
 *.png
 *.out
-out/
+obj
+out

.gitmodules

@@ -1,3 +1,3 @@
 [submodule "images"]
 	path = images
-	url = gitlab@git.datenvorr.at:anton/images.h.git
+	url = https://git.datenvorr.at/anton/images.h.git

.idea/.gitignore

@@ -0,0 +1,8 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml

.idea/misc.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="CMakeWorkspace" PROJECT_DIR="$PROJECT_DIR$" />
+</project>

.idea/modules.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/.idea/raymarcher.iml" filepath="$PROJECT_DIR$/.idea/raymarcher.iml" />
+    </modules>
+  </component>
+</project>

.idea/vcs.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+    <mapping directory="$PROJECT_DIR$/images" vcs="Git" />
+  </component>
+</project>

Makefile

@@ -0,0 +1,31 @@
+
+
+OPTIMIZATION=-O3 -flto
+CC=gcc
+CFLAGS=-Isrc/ -lm -lpthread -Wall -Wextra -pedantic-errors $(OPTIMIZATION) -DPOINT_DTYPE=float
+
+.PHONY: directories
+
+directories:
+	mkdir -p obj out
+
+clean:
+	rm -rf obj/* out/*
+
+obj/scene.o: src/scene.c src/scene.h src/point.h
+	$(CC) $(CFLAGS) -c -o $@ src/scene.c
+
+obj/camera.o: src/camera.c src/camera.h src/point.h
+	$(CC) $(CFLAGS) -c -o $@ src/camera.c
+
+obj/images.o: images/src/images.c images/src/images.h src/point.h
+	$(CC) $(CFLAGS) -c -o $@ images/src/images.c
+
+march: obj/camera.o obj/scene.o obj/images.o src/point.h
+	$(CC) $(CFLAGS) -o out/march $^ marcher.c
+
+bench: obj/camera.o obj/scene.o obj/images.o src/point.h
+	$(CC) $(CFLAGS) -o out/bench $^ bench.c
+
+gpu: obj/camera.o obj/images.o src/point.h
+	$(CC) -fopenacc $(CFLAGS) -o out/gpu $^ gpu.c

bench.c

@@ -0,0 +1,181 @@
+#include <math.h>
+#include <time.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/time.h>
+#include <sys/sysinfo.h>
+#include "images/src/images.h"
+#include "src/scene.h"
+#include "src/camera.h"
+#include "src/point.h"
+
+
+#define BENCH_VERSION "1.0"
+
+
+/*
+
+    Mandelbulb scene object
+
+    Currently cannot be set at a specific location, always resides at origin (0,0,0)
+
+    Color function is just a flat shader, detail is displayed with ambient occlusion
+
+*/
+double mandelbulb_dist(struct point pt, struct scene_object *self) {
+    int iters = (int) self->args[0];
+    double power = self->args[1];
+
+    struct point z = pt;
+	double dr = 1.0;
+	double r = 0.0;
+	for (int i = 0; i < iters ; i++) {
+		r = pt_length(z);
+
+		if (r>2) {
+            break;
+        }
+		
+		// convert to polar coordinates
+		double theta = acos(z.z/r);
+		double phi = atan2(z.y,z.x);
+		dr =  pow(r, power-1.0)*power*dr + 1.0;
+		
+		// scale and rotate the point
+		double zr = pow(r, power);
+		theta = theta*power;
+		phi = phi*power;
+		
+		// convert back to cartesian coordinates
+        z = (struct point) {
+                .x = sin(theta)*cos(phi) * zr + pt.x,
+                .y = sin(phi)*sin(theta) * zr + pt.y,
+                .z = cos(theta) * zr + pt.z
+        };
+	}
+	
+    return 0.5*log(r)*r/dr;
+    
+}
+
+Color mandelbulb_color(struct point hit, struct point direction, struct scene_object *self) {
+    return self->color;
+}
+
+// constructs the scene object
+struct scene_object mandelbulb_new(struct point location, int iters, double power) {
+    struct scene_object so;
+    so.location = location;
+    so.args = malloc(sizeof(double) * 3);
+    so.args[0] = iters;         // iterations
+    so.args[1] = power;         // power
+    so.args[2] = -1;            // reserved for color calculations
+    so.distance = mandelbulb_dist;
+    so.get_color = mandelbulb_color;
+    so.color = color_new(255,255,255);
+    return so;
+}
+
+int run_bench(int size, double pow, int threads, const char path[], int save) {
+    double cam_position = 1.15;
+    int steps = 2000;
+    int iters = 1000;
+    double threshold = 0.0001;
+
+    struct camera cam;
+    cam.fov = 90;
+
+    camera_set_looking_at(&cam, (struct point){.x = cam_position, .y = cam_position, .z = cam_position}, PT_ZERO);
+
+    // create basic scene with up to 10 objects
+    struct scene scene = scene_new(size, size, 1);
+    scene.perf_opts.max_steps = steps;
+    scene.perf_opts.threshold = threshold;
+    scene.perf_opts.speed_cutoff = 10;
+    scene.background = color_new(0,0,0);
+
+    scene_add_obj(&scene, mandelbulb_new(PT_ZERO, iters, pow));
+    
+    Image *img = render_scene(&scene, &cam, threads);
+
+    if (save) {
+        image_save_bmp(*img, path);
+    }
+
+    image_destroy(*img);
+    scene_destroy(scene);
+
+    return 0;  
+}
+
+struct timer {
+    struct timeval start;
+    struct timeval end;
+    char *name;
+};
+
+void timer_start(struct timer *t) {
+    printf("\nStarting bench %s\n", t->name);
+    gettimeofday(&t->start, NULL);
+}
+void timer_end(struct timer *t) {
+    gettimeofday(&t->end, NULL);
+}
+void timer_print(struct timer t) {
+    long time, secs, usecs;
+    secs  = t.end.tv_sec  - t.start.tv_sec;
+    usecs = t.end.tv_usec - t.start.tv_usec;
+    time = ((secs) * 1000 + usecs/1000.0) + 0.5;
+    printf("\nBenchmark %s took %ldms (%.2fs)\n", t.name, time, time / 1000.0f);
+}
+
+int main()
+{
+    int threads = get_nprocs() / 2;
+    struct timer bench;
+
+    printf("Mandelbulb Benchmark v%s\n\nDetected %d threads...\n", BENCH_VERSION, threads);
+    
+    sleep(2);
+
+    bench.name = "1080px render with saving";
+    timer_start(&bench);
+    run_bench(1080, 3.0, threads, "bench-pow3-1080p.bmp", 1);
+    timer_end(&bench);
+    timer_print(bench);
+
+    sleep(2);
+
+    bench.name = "1080px render without saving";
+    timer_start(&bench);
+    run_bench(1080, 3.0, threads, "", 0);
+    timer_end(&bench);
+    timer_print(bench);
+
+    sleep(2);
+
+    bench.name = "10 megapixel render with saving";
+    timer_start(&bench);
+    run_bench(3162, 3.0, threads, "bench-pow3-10mpx.bmp", 1);
+    timer_end(&bench);
+    timer_print(bench);
+
+    sleep(2);
+
+    bench.name = "40 megapixel render with saving";
+    timer_start(&bench);
+    run_bench(6324, 3.0, threads, "bench-pow3-40mpx.bmp", 1);
+    timer_end(&bench);
+    timer_print(bench);
+
+    sleep(2);
+
+    bench.name = "1080px render single threaded without saving";
+    timer_start(&bench);
+    run_bench(1080, 3.0, 1, "", 0);
+    timer_end(&bench);
+    timer_print(bench);
+
+    return 0;
+}

gpu.c

@@ -0,0 +1,186 @@
+// use floats instead of doubles
+#define DTYPE float
+// #define POINT_DTYPE DTYPE
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "src/point.h"
+#include "src/camera.h"
+#include "images/src/images.h"
+
+#define ITERS 100
+#define POWER 3
+
+#define SIZE 1000
+#define STEP_WIDTH (2 / ((DTYPE) (SIZE - 1)))
+
+#define CAM_POSITION 1.35
+
+#define STEPS 100
+#define THRESHOLD 0.001
+
+#include <openacc.h>
+
+
+float mandelbulb_dist(struct point pt) 
+{
+    DTYPE power = POWER;
+
+    struct point z = pt;
+	DTYPE dr = 1.0;
+	DTYPE r = 0.0;
+	for (int i = 0; i < ITERS ; i++) {
+		r = pt_length(z);
+
+		if (r>2) {
+            break;
+        }
+		
+		// convert to polar coordinates
+		DTYPE theta = acos(z.z/r);
+		DTYPE phi = atan2(z.y,z.x);
+		dr =  pow(r, power-1.0)*power*dr + 1.0;
+		
+		// scale and rotate the point
+		DTYPE zr = pow(r, power);
+		theta = theta*power;
+		phi = phi*power;
+		
+		// convert back to cartesian coordinates
+        z = (struct point) {
+                .x = sin(theta)*cos(phi) * zr + pt.x,
+                .y = sin(phi)*sin(theta) * zr + pt.y,
+                .z = cos(theta) * zr + pt.z
+        };
+	}
+	
+    return 0.5*log(r)*r/dr;
+}
+
+struct setup {
+    struct point p0;            // origin
+    struct point direction;     // ray direction
+    struct point x;             // ray movement in col
+    struct point y;             // ray movement in row
+};
+
+struct setup make_setup()
+{
+    // set up camera
+    struct camera cam;
+    cam.fov = 90;
+
+    camera_set_looking_at(&cam, (struct point){.x=CAM_POSITION, .y= CAM_POSITION, .z = CAM_POSITION}, PT_ZERO);
+
+    struct point span_z, span_xy;
+
+    // get rotation axis
+    pt_orthogonal_plane(cam.direction, &span_z, &span_xy);
+
+    printf("rendering %ix%ipx\n", SIZE, SIZE);
+
+    // distance each ray has from anothe on the ortogonal plane
+    //DTYPE step_dist = 2 / (DTYPE) (width - 1);
+
+    // vectors to move on the projection plane
+    struct point move_right = pt_scale(span_xy, STEP_WIDTH);
+    struct point move_up =    pt_scale(span_z,  STEP_WIDTH);;
+
+    // set starting point
+    struct point starting_point = pt_normalize(cam.direction);
+
+    // rotate starting point to (0,0)
+    starting_point = pt_add(starting_point, pt_mult(move_right, - SIZE / (DTYPE) 2));
+    starting_point = pt_add(starting_point, pt_mult(move_up, - SIZE / (DTYPE) 2));
+
+    return (struct setup) {
+        cam.location, starting_point, span_xy, span_z
+    };
+}
+
+int main()
+{
+    struct setup setup = make_setup();
+    struct point start = setup.p0;
+    
+    //printf("device num acc_device_current: %d\n", acc_get_num_devices(acc_device_current));
+    //printf("device num acc_device_none: %d\n", acc_get_num_devices(acc_device_none));
+    //printf("device num acc_device_default: %d\n", acc_get_num_devices(acc_device_default));
+    //printf("device num acc_device_host: %d\n", acc_get_num_devices(acc_device_host));
+    //printf("device num acc_device_not_host: %d\n", acc_get_num_devices(acc_device_not_host));
+    //printf("device num acc_device_nvidia: %d\n", acc_get_num_devices(acc_device_nvidia));
+    //printf("device num acc_device_radeon: %d\n", acc_get_num_devices(acc_device_radeon));
+
+    // get backing buff
+    int* buff = calloc(sizeof(int), SIZE * SIZE);
+
+    // indicate malloc failure
+    if (buff == NULL)
+        return -255;
+
+    printf("Before kernel\n");
+
+#pragma acc data copy(buff)
+{
+    // kernel goes brr
+    #pragma acc kernels
+    for (int x = 0; x < SIZE; x++) {
+        for (int y = 0; y < SIZE; y++) {
+            // get direction
+            struct point offset = pt_add(pt_mult(setup.x, STEP_WIDTH * x), pt_mult(setup.y, STEP_WIDTH * y));
+            struct point direction = pt_add(setup.direction, offset);
+            // get start
+            struct point loc = start;
+            // march!
+            DTYPE dist;
+            int res = -1;
+
+            for (int i = 0; i < STEPS; i++) {
+                dist = mandelbulb_dist(loc);
+                if (dist < THRESHOLD) {
+                    res = i;
+                    break;
+                }
+                if (dist > 100) {
+                    break;
+                }
+                loc = pt_add(loc, pt_scale(direction, dist));
+            }
+            buff[y * SIZE + x] = res;
+        }
+    }
+}
+
+    printf("after kernel\n");
+
+    // convert distance field into image
+
+    Image img;
+
+    // initialize shared pixel buffer
+    image_new(SIZE, SIZE, &img);
+    
+    #pragma acc parallel
+    for (unsigned int x = 0; x < SIZE; x++) {
+        #pragma acc loop
+        for (unsigned int y = 0; y < SIZE; y++) {
+            if (buff[y * SIZE + x] < 0) {
+                image_set_px(img, x, y, 0, 0, 0);
+            } else {
+                // float in range of [0,1]
+                DTYPE fac = buff[y * SIZE + x] / (DTYPE) STEPS;
+                // calc shade 
+                int shade = ((1-fac) * 255);
+                image_set_px(img, x, y, shade, shade, shade);
+            }
+        }
+    }
+
+    printf("after encoding\n");
+
+
+    image_save_bmp(img, "gpu-goes-brrrrrrr.bmp");
+
+    return 0;
+}

images

@@ -1 +1 @@
-Subproject commit e20f4cb891ae1f6ac34f7572ea6847957b7195db
+Subproject commit f503f1835fd47de323b19d8f3f1ea0fc542dd6f6

marcher.c

@@ -1,6 +1,10 @@
 #include <math.h>
-#include "images/images.h"
-#include "marcher.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include "images/src/images.h"
+#include "src/scene.h"
+#include "src/camera.h"
+#include "src/point.h"
 
 #define SCENE_MOD 2
 
@@ -15,15 +19,15 @@
 
 */
 
-double circle_dist(Point x, SceneObject *self) {
+double circle_dist(struct point x, struct scene_object *self) {
     double r = self->args[0];
     return pt_dist(pt_mod(x, SCENE_MOD), self->location) - r;
 }
 
-Color circle_color(Point hit, Point direction, SceneObject *self) {
-    Point obj_direction = self->location;
+Color circle_color(struct point hit, struct point direction, struct scene_object *self) {
+    struct point obj_direction = self->location;
 
-    pt_sub(&obj_direction, pt_mod(hit, SCENE_MOD));
+    obj_direction = pt_sub(obj_direction, pt_mod(hit, SCENE_MOD));
 
     double angle = pt_angle(direction, obj_direction) / M_PI * 180;
     Color color = self->color;
@@ -34,15 +38,16 @@ Color circle_color(Point hit, Point direction, SceneObject *self) {
     return color;
 }
 // constructs the scene object
-SceneObject circle_new(Point loc, double radius) {
-    SceneObject so;
-    so.location = loc;
-    so.args = malloc(sizeof(double) * 2);
-    so.args[0] = radius;
-    so.distance = circle_dist;
-    so.get_color = circle_color;
-    so.color = color_new(255,255,255);
-    return so;
+struct scene_object circle_new(struct point loc, double radius) {
+    double * args = malloc(sizeof (double) * 2);
+    args[0] = radius;
+    return (struct scene_object) {
+            .location = loc,
+            .args = args,
+            .distance = circle_dist,
+            .get_color = circle_color,
+            .color = color_new(255, 255, 255),
+    };
 }
 
 
@@ -55,11 +60,11 @@ SceneObject circle_new(Point loc, double radius) {
     Color function is just a flat shader, detail is displayed with ambient occlusion
 
 */
-double mandelbulb_dist(Point pt, SceneObject *self) {
+double mandelbulb_dist(struct point pt, struct scene_object *self) {
     int iters = self->args[0];
     double power = self->args[1];
 
-    Point z = pt;
+    struct point z = pt;
 	float dr = 1.0;
 	float r = 0.0;
 	for (int i = 0; i < iters ; i++) {
@@ -79,39 +84,43 @@ double mandelbulb_dist(Point pt, SceneObject *self) {
 		theta = theta*power;
 		phi = phi*power;
 		
-		// convert back to cartesian coordinates
-		z = pt_mult(pt_new(sin(theta)*cos(phi), sin(phi)*sin(theta), cos(theta)), zr);
-		pt_add(&z, pt);
+		// convert back to cartesian coordinates, add zr and the old pt
+		z = (struct point) {
+            .x = sin(theta)*cos(phi) * zr + pt.x,
+            .y = sin(phi)*sin(theta) * zr + pt.y,
+            .z = cos(theta) * zr + pt.z
+        };
 	}
 	
     return 0.5*log(r)*r/dr;
-    
 }
 
-Color mandelbulb_color(Point hit, Point direction, SceneObject *self) {
+Color mandelbulb_color(struct point hit, struct point direction, struct scene_object *self) {
     return self->color;
 }
 // constructs the scene object
-SceneObject mandelbulb_new(Point location, int iters, double power) {
-    SceneObject so;
-    so.location = location;
-    so.args = malloc(sizeof(double) * 3);
-    so.args[0] = iters;         // iterations
-    so.args[1] = power;         // power
-    so.args[2] = -1;            // reserved for color calculations
-    so.distance = mandelbulb_dist;
-    so.get_color = mandelbulb_color;
-    so.color = color_new(255,255,255);
-    return so;
+struct scene_object mandelbulb_new(struct point location, int iters, double power) {
+    double * args = malloc(sizeof(double) * 3);
+    args[0] = iters;
+    args[1] = power;
+    args[2] = -1;
+
+    return (struct scene_object) {
+        .location=  location,
+        .args= args,
+        .distance=  mandelbulb_dist,
+        .get_color=  mandelbulb_color,
+        .color=  color_new(255,255,255),
+    };
 }
 
 int main(int argc, char* argv[]) {
-    float dpi = 800;
+    float dpi = 200;
 
     int threads = 32;
     int size = dpi * 27.56f;       // 400dpi by 70cm size
     float pow = 3;
-    float cam_position = 1.15;
+    float cam_position = 1.35;
     int steps = 1000;
     int iters = 500;
     float threshold = 0.001;
@@ -131,15 +140,13 @@ int main(int argc, char* argv[]) {
 
     printf("Rendering to %s\n", path);
 
-    Camera cam;
+    struct camera cam;
     cam.fov = 90;
 
-    camera_set_looking_at(&cam, pt_new(cam_position, cam_position, cam_position), pt_new(0,0,0));
-
-    
+    camera_set_looking_at(&cam, (struct point){.x=cam_position, .y= 0, .z = cam_position}, PT_ZERO);
 
     // create basic scene with up to 10 objects
-    Scene scene = scene_new(size, size, 1);
+    struct scene scene = scene_new(size, size, 1);
     scene.perf_opts.max_steps = steps;
     scene.perf_opts.threshold = threshold;
     scene.perf_opts.speed_cutoff = 10;
@@ -147,13 +154,13 @@ int main(int argc, char* argv[]) {
 
     //scene_add_obj(&scene, circle_new(pt_new(SCENE_MOD / 2.0, SCENE_MOD/ 2.0, SCENE_MOD / 2.0), .2));
 
-    scene_add_obj(&scene, mandelbulb_new(pt_new(0,0,0), iters, pow));
+    scene_add_obj(&scene, mandelbulb_new(PT_ZERO, iters, pow));
     
     Image *img = render_scene(&scene, &cam, threads);
 
     image_save_bmp(*img, path);
 
-    image_destroy_shared(*img);
+    image_destroy(*img);
     scene_destroy(scene);
 
     return 0;  

marcher.h

@@ -1,97 +0,0 @@
-#ifndef __MARCHER_H__
-#define __MARCHER_H__
-
-#include "images/images.h"
-
-// define pi if not available
-#ifndef M_PI
-#define M_PI 3.14159265358979323846
-#endif
-
-struct __myvec;
-struct __mymtrx;
-struct __mycam;
-struct __myobject;
-struct __myscene;
-
-typedef struct __myvec {
-    double x;
-    double y;
-    double z;
-} Point;
-
-typedef struct __mymtrx {
-    double entries[9];
-} Matrix;
-
-inline Point pt_new(double x, double y, double z);
-inline Point pt_scale(Point pt, double length);
-inline Point pt_normalize(Point pt);
-inline double pt_length(Point pt);
-inline void pt_add(Point* pt, Point add);
-inline void pt_sub(Point* pt, Point sub);
-inline double pt_dist(Point p1, Point p2);
-inline Point pt_mod(Point pt, double mod);
-inline double pt_dot(Point a, Point b);
-inline Point pt_cross(Point a, Point b);
-inline double pt_angle(Point a, Point b);
-inline void pt_print(Point pt);
-inline void pt_print_n(const char* name, Point pt);
-
-
-typedef struct __mycam {
-    Point location;
-    Point direction;
-    unsigned int fov;
-} Camera;
-
-Camera camera_new(Point direction, unsigned int fov);
-void camera_set_looking_at(Camera *cam, Point origin, Point thing);
-
-// Scene objects have a position, some args, and a distance calculation function
-// the distance calc function has the following signature:
-// double distanceTo(Point myLocation, double * myArgs, Point externalPoint)
-// where myLocation is this.location, myArgs is this.args and externalPoint is the point from wich we want to know the distance
-// the get_color function takes args: point_hit, direction_hit, myArgs, MyLocation, MyColor
-typedef struct __myobject {
-    Point location;
-    double * args;
-    double (*distance)(Point, struct __myobject *); 
-    Color (*get_color)(Point, Point, struct __myobject *);
-    Color color;
-    struct __myscene* scene;
-} SceneObject;
-
-
-typedef struct __perfopts {
-    int speed_cutoff;
-    int max_steps;
-    double threshold;
-} PerformanceOptimizations;
-
-
-typedef struct __myscene {
-    unsigned int width;
-    unsigned int height;
-    SceneObject * objects;
-    int object_count;
-    int allocated_space;
-    // performance opts
-    PerformanceOptimizations perf_opts;
-    // colors etc
-    Color background;
-} Scene;
-
-Image* render_scene(Scene *scene, Camera *camera, unsigned int threads);
-
-Scene scene_new(unsigned int width, unsigned int height, int obj_count);
-
-void scene_add_obj(Scene* scene, SceneObject object);
-
-void scene_destroy(Scene scene);
-
-#include "src/point.c"
-#include "src/camera.c"
-#include "src/scene.c"
-
-#endif

src/camera.c

@@ -1,12 +1,32 @@
-#include "../marcher.h"
-#include <unistd.h>
 #include <sys/wait.h>
 #include <sys/mman.h>
-
-
-Camera camera_new(Point direction, unsigned int fov) {
-    Camera camera;
-    camera.location = pt_new(0,0,0);
+#include <stdlib.h>
+#include <stdio.h>
+#include <pthread.h>
+#include "point.h"
+#include "camera.h"
+
+struct thread_args {
+    struct point start;
+    int thread_id;
+    int thread_count;
+    int height;
+    int width;
+    struct point move_up;
+    struct point move_right;
+    void (*callback)(struct point, int, int);
+};
+
+static void * camera_iterate_rays_const_dist_thread(void* args);
+
+
+struct camera camera_new(struct point direction, unsigned int fov) {
+    struct camera camera;
+    camera.location = (struct point) {
+        .x = 0,
+        .y = 0,
+        .z = 0
+    };
     camera.fov = fov;
 
     // normalize camera direction
@@ -15,160 +35,118 @@ Camera camera_new(Point direction, unsigned int fov) {
     return camera;
 }
 
-void camera_set_looking_at(Camera *cam, Point origin, Point thing) {
+void camera_set_looking_at(struct camera *cam, struct point origin, struct point thing) {
     cam->location = origin;
-    pt_sub(&thing, origin);
-    cam->direction = pt_normalize(thing);
+    cam->direction = pt_normalize(pt_sub(thing, origin));
 }
 
-void camera_iterate_rays_const_angle(Camera camera, int width, int height, int threads, void (*callback)(Point, int, int)) {
-    // negative threads => single threaded.
-    if (threads < 0) threads = 0;
+void camera_iterate_rays_const_dist(struct camera camera, int width, int height, int thread_count, void (*callback)(struct point, int, int)) {
+    // negative thread_count => single threaded.
+    if (thread_count < 0) thread_count = 0;
 
-    Point span_z, span_xy;
+    struct point span_z, span_xy;
 
     // get rotation axis
     pt_orthogonal_plane(camera.direction, &span_z, &span_xy);
 
-    printf("rendering %ix%i px", width, height);
-
-    pt_print_n("span_xy", span_xy);
-    pt_print_n("span_z", span_z);
-
-    // angle between rays
-    double angle_step = camera.fov / (double) (width - 1);
-
-    // rotation applied to reach the outmost end of the view
-    double angle_start_h = - (camera.fov / 2.0);
-    double angle_start_v = ((angle_step * (height - 1)) / 2) ;
-
-    printf("step: %f\nstart_h: %f\nstart_v: %f\n", angle_step, angle_start_h, angle_start_v);
+    printf("rendering %ix%ipx\n", width, height);
 
-    // calculate both rotation matrices (expensive!)
-    Matrix rot_z = mtrx_rotation(span_z, angle_step);
-    Matrix rot_xy = mtrx_rotation(span_xy, -angle_step);
+    // distance each ray has from anothe on the ortogonal plane
+    double step_dist = 2 / (double) (width - 1);
 
-    // rotate vector to starting location (bot left of screen)
-    // (very expensive!)
-    Point starting_point = mtrx_mult(
-        mtrx_rotation(span_xy, angle_start_v),
-        mtrx_mult(
-            mtrx_rotation(span_z, angle_start_h),
-            camera.direction
-        )
-    );
+    // vectors to move on the projection plane
+    struct point move_right = pt_scale(span_xy, step_dist);
+    struct point move_up =    pt_scale(span_z,  step_dist);;
 
-    // initialize threads
-    int thread_id = 0;
-    for (int i = 0; i < threads - 1; i++) {
-        if (fork() == 0) {
-            thread_id = i + 1;
-            break;
-        }
+    // set starting point
+    struct point starting_point = pt_normalize(camera.direction);
+    
+    // rotate starting point to (0,0)
+    starting_point = pt_add(starting_point, pt_mult(move_right, - width / (double) 2));
+    starting_point = pt_add(starting_point, pt_mult(move_up, - height / (double) 2));
+
+    if (thread_count < 2) {
+        //TODO implement single threaded work here
+        struct thread_args arg = {
+                .start = starting_point,
+                .thread_id = 0,
+                .thread_count = 1,
+                .height = height,
+                .width = width,
+                .move_up = move_up,
+                .move_right = move_right,
+                .callback = callback
+        };
+
+        camera_iterate_rays_const_dist_thread(&arg);
+
+        return;
     }
 
-    // this point is rotated for every pixel
-    Point curr_pt = starting_point;
-    // (0,0) screenspace is bottom left corner
-    for (int y = 0; y < height; y++) {
-        curr_pt = mtrx_mult(rot_xy, starting_point);
-        // move starting point one row down
-        starting_point = curr_pt;
-
-        if (y % threads != thread_id) continue;
-
-        for (int x = 0; x < width; x++) {
-            callback(curr_pt, x, y);
-            curr_pt = mtrx_mult(rot_z, curr_pt); // rotate point
-        }
+    // initialize thread_count
+    pthread_t * threads = malloc(sizeof(pthread_t) * thread_count);
+    struct thread_args* args = malloc(sizeof(struct thread_args) * thread_count);
+
+    for (int i = 0; i < thread_count; i++) {
+        args[i] = (struct thread_args) {
+            .start = starting_point,
+            .thread_id = i,
+            .thread_count = thread_count,
+            .height = height,
+            .width = width,
+            .move_up = move_up,
+            .move_right = move_right,
+            .callback = callback
+        };
+
+        pthread_create(threads + i, NULL, camera_iterate_rays_const_dist_thread, (void*) (args + i));
     }
 
-    if (thread_id != 0) {
-        printf("Thread %i is finished\n", thread_id);
-        exit(0);
-    }
+    //struct thread_args {
+    //    struct point start;
+    //    int thread_id;
+    //    int thread_count;
+    //    int height;
+    //    int width;
+    //    struct point move_up;
+    //    struct point move_right;
+    //    void (*callback)(struct point, int, int);
+    //};
 
-    int status;
-    for (int i = 0; i < threads - 1; i++) {
-        while(wait(&status) > 0) {}
-    }
 
-    printf("got threads\n");
+    for (int i = 0; i < thread_count; i++) {
+        pthread_join(threads[i], NULL);
+    }
 }
 
-void camera_iterate_rays_const_dist(Camera camera, int width, int height, int threads, void (*callback)(Point, int, int)) {
-    // negative threads => single threaded.
-    if (threads < 0) threads = 0;
-
-    Point span_z, span_xy;
-
-    // get rotation axis
-    pt_orthogonal_plane(camera.direction, &span_z, &span_xy);
-
-    printf("rendering %ix%i px\n", width, height);
-
-    pt_print_n("span_xy", span_xy);
-    pt_print_n("span_z", span_z);
-
-
-    // distance each ray has from anothe on the ortogonal plane
-    double step_dist = 2 / (double) (width - 1);
-
-    // vectors to move on the projection plane
-    Point move_right = pt_scale(span_xy, step_dist);
-    Point move_up =    pt_scale(span_z,  step_dist);;
-
-    printf("step: %f\n", step_dist);
-    // set starting point
-    Point starting_point = pt_normalize(camera.direction);
-    
-    // rotate starting point to (0,0)
-    pt_add(&starting_point, pt_mult(move_right, - width / (double) 2));
-    pt_add(&starting_point, pt_mult(move_up, - height / (double) 2));
-
-    // initialize threads
-    int thread_id = 0;
-    for (int i = 0; i < threads - 1; i++) {
-        if (fork() == 0) {
-            thread_id = i + 1;
-            break;
-        }
-    }
+static void * camera_iterate_rays_const_dist_thread(void* arg_ptr) {
+    // explicit cast to make gcc happy
+    struct thread_args* args = (struct thread_args*) arg_ptr;
 
     // this point is moved for every pixel
-    Point curr_pt = starting_point;
+    struct point curr_pt = args->start;
 
     // (0,0) screenspace is bottom left corner
-    for (int y = 0; y < height; y++) {
+    for (int y = 0; y < args->height; y++) {
         // move one row up (this has to be done in every thread!)
-        pt_add(&starting_point, move_up);
+        args->start = pt_add(args->start, args->move_up);
 
         // only render the lines this thread is responsible for
-        if (y % threads != thread_id) continue;
-        
+        if (y % args->thread_count != args->thread_id) continue;
+
         // display progress in percent
-        if (height > 200 && y % (height / 100) == 0 && y != 0) {
-            printf("\r%02i%%", (y * 100) / height);
+        if (args->height > 200 && y % (args->height / 100) == 0 && y != 0) {
+            printf("\r%02i%%", (y * 100) / args->height);
             fflush(stdout);
         }
 
         // actually iterate this line
-        curr_pt = starting_point;
-        for (int x = 0; x < width; x++) {
-            callback(curr_pt, x, y);
-            pt_add(&curr_pt, move_right); // move pt right to next pt
+        curr_pt = args->start;
+        for (int x = 0; x < args->width; x++) {
+            args->callback(curr_pt, x, y);
+            curr_pt = pt_add(curr_pt, args->move_right); // move pt right to next pt
         }
     }
 
-    if (thread_id != 0) {
-        printf("Thread %i is finished\n", thread_id);
-        exit(0);
-    }
-
-    int status;
-    for (int i = 0; i < threads - 1; i++) {
-        while(wait(&status) > 0) {}
-    }
-
-    printf("got threads\n");
-}
+    return NULL;
+}

src/camera.h

@@ -0,0 +1,11 @@
+#pragma once
+
+struct camera {
+    struct point location;
+    struct point direction;
+    unsigned int fov;
+};
+
+struct camera camera_new(struct point direction, unsigned int fov);
+void camera_set_looking_at(struct camera *cam, struct point origin, struct point thing);
+void camera_iterate_rays_const_dist(struct camera camera, int width, int height, int thread_count, void (*callback)(struct point, int, int));

src/point.c

@@ -1,180 +0,0 @@
-#include <math.h>
-#include <stdio.h>
-
-// basically a vector3
-inline Point pt_new(double x, double y, double z) {
-    Point pt;
-    pt.x = x;
-    pt.y = y;
-    pt.z = z;
-    return pt;
-}
-
-// scale vector to length
-inline Point pt_scale(Point pt, double length) {
-    double f = length / pt_length(pt);
-    return pt_new(
-        pt.x * f,
-        pt.y * f,
-        pt.z * f
-    );
-}
-
-inline Point pt_mult(Point pt, double scalar) {
-    return pt_new(
-        pt.x * scalar,
-        pt.y * scalar,
-        pt.z * scalar
-    );
-}
-
-// return internal angle between a and b
-inline double pt_angle(Point a, Point b) {
-    return acos(pt_dot(
-        pt_normalize(a),
-        pt_normalize(b)
-    ));
-}
-
-// get the length of vector
-inline double pt_length(Point pt) {
-    return sqrt((pt.x * pt.x) + (pt.y * pt.y) + (pt.z * pt.z));
-}
-
-// add the vector add to the vector pt
-inline void pt_add(Point* pt, Point add) {
-    pt->x = pt->x + add.x;
-    pt->y = pt->y + add.y;
-    pt->z = pt->z + add.z;
-}
-
-// add the vector add to the vector pt
-inline void pt_sub(Point* pt, Point sub) {
-    pt->x -= sub.x;
-    pt->y -= sub.y;
-    pt->z -= sub.z;
-}
-
-inline double pt_dist(Point p1, Point p2) {
-    pt_sub(&p1, p2);
-    return pt_length(p1);
-}
-
-// normalize a vector
-inline Point pt_normalize(Point pt) {
-    return pt_scale(pt, 1);
-}
-
-// dot product of two vectors
-inline double pt_dot(Point a, Point b) {
-    return a.x*b.x + a.y*b.y + a.z*b.z;
-}
-
-// cross product of two vectors
-inline Point pt_cross(Point a, Point b) {
-    return pt_new(
-        a.y*b.z - a.z*b.y, 
-        a.z*b.x - a.x*b.z,
-        a.x*b.y - a.y*b.x
-    );
-}
-
-inline void pt_print(Point pt) {
-    printf("(%f, %f, %f)\n", pt.x, pt.y, pt.z);
-}
-
-inline void pt_print_n(const char* name, Point pt) {
-    printf("%s: (%f, %f, %f)\n", name, pt.x, pt.y, pt.z);
-}
-
-// find two vectors that span the orthogonal plane, where 
-// span_xy is a vector lying on the xy-plane (and pointing left)
-// and span_z is orthogonal to span_xy pointing "upwards"
-void pt_orthogonal_plane(Point pt, Point *span_z, Point *span_xy) {
-    pt = pt_normalize(pt);
-
-    // get the vector lying on the xy axis
-    // this is done by 
-    *span_xy = pt_normalize(pt_cross(pt_new(0,0,1), pt)); // points to the "left" (of the viewing direction)
-
-    // now use this, to find the vector 
-    *span_z = pt_normalize(pt_cross(pt, *span_xy));
-}
-
-inline Point pt_mod(Point pt, double mod) {
-    return pt_new(
-        fabs(fmod(pt.x, mod)),
-        fabs(fmod(pt.y, mod)),
-        fabs(fmod(pt.z, mod))
-    );
-}
-
-
-///////////////////////////////
-////// Matrix operations //////
-///////////////////////////////
-
-
-/* create a new matrix with entries:
-    x1 x2 x3
-    y1 y2 y3
-    z1 z2 z3
-*/
-inline Matrix mtrx_new(double x1, double x2, double x3,
-                       double y1, double y2, double y3,
-                       double z1, double z2, double z3) 
-{
-    Matrix m;
-    m.entries[0] = x1;
-    m.entries[1] = y1;
-    m.entries[2] = z1;
-    m.entries[3] = x2;
-    m.entries[4] = y2;
-    m.entries[5] = z2;
-    m.entries[6] = x3;
-    m.entries[7] = y3;
-    m.entries[8] = z3;
-    return m;
-}
-
-inline Point mtrx_mult(Matrix mtrx, Point pt) {
-    Point result;
-
-    double *m = mtrx.entries;
-
-    result.x = m[0] * pt.x + m[3] * pt.y + m[6] * pt.z;
-    result.y = m[1] * pt.x + m[4] * pt.y + m[7] * pt.z;
-    result.z = m[2] * pt.x + m[5] * pt.y + m[8] * pt.z;
-
-    return result;
-}
-
-// create a rotation matrix around an axis given by the normalized axis vector (u)
-// taken from https://en.wikipedia.org/wiki/Rotation_matrix#Rotation_matrix_from_axis_and_angle
-Matrix mtrx_rotation(Point u, double theta) {
-    double theta_rad = theta * (M_PI / 180);
-    double cost = cos(theta_rad);
-    double sint = sin(theta_rad);
-
-    return mtrx_new(
-        cost+u.x*u.x*(1-cost),     u.x*u.y*(1-cost)-u.z*sint, u.x*u.z*(1-cost)+u.y*sint,
-        u.y*u.x*(1-cost)+u.z*sint, cost+u.y*u.y*(1-cost),     u.y*u.z*(1-cost)-u.x*sint,
-        u.z*u.x*(1-cost)-u.y*sint, u.z*u.y*(1-cost)+u.x*sint, cost+u.z*u.z*(1-cost)
-    );
-}
-
-void mtrx_print(Matrix mtrx) {
-    printf("  %8.2f %8.2f %8.2f\n  %8.2f %8.2f %8.2f\n  %8.2f %8.2f %8.2f\n",
-        mtrx.entries[0], mtrx.entries[3], mtrx.entries[6],
-        mtrx.entries[1], mtrx.entries[4], mtrx.entries[7],
-        mtrx.entries[2], mtrx.entries[5], mtrx.entries[8]
-    );
-}
-
-inline Matrix mtrx_outer_prod(Point a, Point b) {
-    return mtrx_new(
-        a.x*b.x, a.x*b.y, a.x*b.z,
-        a.y*b.x, a.y*b.y, a.y*b.z,
-        a.z*b.x, a.z*b.y, a.z*b.z
-    );
-}

src/point.h

@@ -0,0 +1,149 @@
+#pragma once
+
+#ifndef POINT_DTYPE
+#define POINT_DTYPE double
+#endif
+
+
+struct point {
+    POINT_DTYPE x;
+    POINT_DTYPE y;
+    POINT_DTYPE z;
+};
+
+#define PT_ZERO ((struct point) {.x=0, .y=0, .z=0})
+#define PT_NEW(x,y,z) ((struct point){(x), (y), (z)})
+
+static struct point pt_scale(struct point pt, POINT_DTYPE length);
+static struct point pt_normalize(struct point pt);
+static struct point pt_mult(struct point pt, POINT_DTYPE scalar);
+static POINT_DTYPE pt_length(struct point pt);
+static struct point pt_add(struct point pt, struct point add);
+static struct point pt_sub(struct point pt, struct point sub);
+static POINT_DTYPE pt_dist(struct point p1, struct point p2);
+static struct point pt_mod(struct point pt, POINT_DTYPE mod);
+static POINT_DTYPE pt_dot(struct point a, struct point b);
+static struct point pt_cross(struct point a, struct point b);
+static POINT_DTYPE pt_angle(struct point a, struct point b);
+static void pt_print(struct point pt);
+static void pt_print_n(const char* name, struct point pt);
+static void pt_orthogonal_plane(struct point pt, struct point *span_z, struct point *span_xy);
+
+#include <math.h>
+#include <stdio.h>
+#include "point.h"
+
+// get the length of vector
+static inline POINT_DTYPE pt_length_inline (struct point pt) __attribute__((always_inline));
+
+static inline struct point pt_mult(struct point pt, POINT_DTYPE scalar) {
+    return (struct point) {
+        .x = pt.x * scalar,
+        .y = pt.y * scalar,
+        .z = pt.z * scalar
+    };
+}
+
+// return internal angle between a and b
+static inline POINT_DTYPE pt_angle(struct point a, struct point b) {
+    return acos(pt_dot(
+        pt_normalize(a),
+        pt_normalize(b)
+    ));
+}
+
+// get the length of vector
+static inline POINT_DTYPE pt_length_inline (struct point pt) {
+    return sqrt((pt.x * pt.x) + (pt.y * pt.y) + (pt.z * pt.z));
+}
+
+static inline POINT_DTYPE pt_length(struct point pt) {
+    return pt_length_inline(pt);
+}
+
+// add the vector add to the vector pt
+static inline struct point pt_add(struct point pt, struct point add) {
+    return (struct point) {
+        .x = pt.x + add.x,
+        .y = pt.y + add.y,
+        .z = pt.z + add.z,
+    };
+}
+
+// add the vector add to the vector pt
+static inline struct point pt_sub(struct point pt, struct point sub) {
+    return (struct point) {
+        .x = pt.x - sub.x,
+        .y = pt.y - sub.y,
+        .z = pt.z - sub.z,
+    };
+}
+
+static inline POINT_DTYPE pt_dist(struct point p1, struct point p2) {
+    return pt_length_inline(pt_sub(p1, p2));
+}
+
+// normalize a vector
+static inline struct point pt_normalize(struct point pt) {
+    POINT_DTYPE length = pt_length(pt);
+
+    return (struct point) {
+        .x = pt.x / length,
+        .y = pt.y / length,
+        .z = pt.z / length
+    };
+}
+
+// scale vector to length
+static inline struct point pt_scale(struct point pt, POINT_DTYPE length) {
+    POINT_DTYPE f = length / pt_length_inline(pt);
+    return (struct point) {
+            .x = pt.x * f,
+            .y = pt.y * f,
+            .z = pt.z * f
+    };
+}
+
+// dot product of two vectors
+static inline POINT_DTYPE pt_dot(struct point a, struct point b) {
+    return a.x*b.x + a.y*b.y + a.z*b.z;
+}
+
+// cross product of two vectors
+static inline struct point pt_cross(struct point a, struct point b) {
+    return (struct point) {
+        .x = a.y*b.z - a.z*b.y,
+        .y = a.z*b.x - a.x*b.z,
+        .z = a.x*b.y - a.y*b.x
+    };
+}
+
+static inline void pt_print(struct point pt) {
+    printf("(%f, %f, %f)\n", pt.x, pt.y, pt.z);
+}
+
+static inline void pt_print_n(const char* name, struct point pt) {
+    printf("%s: (%f, %f, %f)\n", name, pt.x, pt.y, pt.z);
+}
+
+// find two vectors that span the orthogonal plane, where 
+// span_xy is a vector lying on the xy-plane (and pointing left)
+// and span_z is orthogonal to span_xy pointing "upwards"
+static inline void pt_orthogonal_plane(struct point pt, struct point *span_z, struct point *span_xy) {
+    pt = pt_normalize(pt);
+
+    // get the vector lying on the xy axis
+    // this is done by
+    *span_xy = pt_normalize(pt_cross(PT_NEW(0,0,1), pt)); // points to the "left" (of the viewing direction)
+
+    // now use this, to find the vector 
+    *span_z = pt_normalize(pt_cross(pt, *span_xy));
+}
+
+static inline struct point pt_mod(struct point pt, POINT_DTYPE mod) {
+    return (struct point) {
+        .x = fabs(fmod(pt.x, mod)),
+        .y = fabs(fmod(pt.y, mod)),
+        .z = fabs(fmod(pt.z, mod))
+    };
+}

src/scene.c

@@ -1,36 +1,37 @@
-#include "../marcher.h"
-#include "../images/images.h"
-
+#include "../images/src/images.h"
+#include "scene.h"
+#include "camera.h"
+#include "point.h"
 #include <float.h>
+#include <stdlib.h>
 
 static Image* current_image;
-static Scene* current_scene;
-static Camera* current_camera;
+static struct scene* current_scene;
+static struct camera* current_camera;
 
-Color march_ray(Point origin, Point direction, Scene* scene);
-void camera_iter_callback(Point direction, int x, int y);
+Color march_ray(struct point origin, struct point direction, struct scene* scene);
+void camera_iter_callback(struct point direction, int x, int y);
 
 
-Scene scene_new(unsigned int width, unsigned int height, int obj_count) {
-    Scene scene;
+struct scene scene_new(unsigned int width, unsigned int height, int obj_count) {
+    struct scene scene;
     scene.height = height;
     scene.width = width;
     scene.object_count = 0;
-    scene.objects = malloc(obj_count * sizeof(SceneObject));
+    scene.objects = malloc(obj_count * sizeof(struct scene_object));
     scene.allocated_space = obj_count;
     scene.background = color_new(0,0,0);
 
-    PerformanceOptimizations perf_opts;
-    perf_opts.speed_cutoff = 0;
-    perf_opts.max_steps = 32;
-    perf_opts.threshold = 0.02;
-
-    scene.perf_opts = perf_opts;
+    scene.perf_opts = (struct performance_optimization) {
+        .speed_cutoff = 0,
+        .max_steps = 32,
+        .threshold = 0.02
+    };
 
     return scene;
 }
 
-void scene_add_obj(Scene* scene, SceneObject object) {
+void scene_add_obj(struct scene * scene, struct scene_object object) {
     if (scene->object_count >= scene->allocated_space) return; // limit reached
     // TODO realloc
 
@@ -44,13 +45,13 @@ void scene_add_obj(Scene* scene, SceneObject object) {
 
 // render out the scene with threads
 // creates a shared image, so destroy with image_destroy_shared then free struct with free_shared_memory
-Image* render_scene(Scene *scene, Camera *camera, unsigned int threads) {
+Image* render_scene(struct scene *scene, struct camera *camera, unsigned int threads) {
     current_image = malloc(sizeof(Image));
     current_scene = scene;
     current_camera= camera;
 
     // initialize shared pixel buffer
-    image_new_shared(scene->width, scene->height, current_image);
+    image_new(scene->width, scene->height, current_image);
 
     // iterate over the rays
     camera_iterate_rays_const_dist(*camera, scene->width, scene->height, threads, camera_iter_callback);
@@ -61,20 +62,20 @@ Image* render_scene(Scene *scene, Camera *camera, unsigned int threads) {
 }
 
 // march the ray, set the color. repeated for each direction generated by the camera
-void camera_iter_callback(Point direction, int x, int y) {
+void camera_iter_callback(struct point direction, int x, int y) {
     Color c = march_ray(current_camera->location, direction, current_scene);
     image_set_px_c(*current_image, x, y, c);
 }
 
 
 
-Color march_ray(Point origin, Point direction, Scene* scene) {
+Color march_ray(struct point origin, struct point direction, struct scene* scene) {
     // some local variables
-    Point pos = origin;
+    struct point pos = origin;
     double closest_encounter = DBL_MAX;
     double dist = closest_encounter;
     // the closest object we have
-    SceneObject* closest_obj = scene->objects;
+    struct scene_object* closest_obj = scene->objects;
 
     // get steps, threshold from scene
     int steps = scene->perf_opts.max_steps;
@@ -88,7 +89,7 @@ Color march_ray(Point origin, Point direction, Scene* scene) {
         // find distance to closest object
         for(int i = 0; i < scene->object_count; i++) {
             // get pointer to scene obj
-            SceneObject* obj = scene->objects + i;
+            struct scene_object* obj = scene->objects + i;
             double curr_dist = scene->objects[i].distance(pos, obj);
 
             // if we are close
@@ -106,8 +107,8 @@ Color march_ray(Point origin, Point direction, Scene* scene) {
         if (dist < closest_encounter) closest_encounter = dist;
 
         // scale direction vector to distance, then add it to our position
-        Point step_vector = pt_scale(direction, dist);
-        pt_add(&pos, step_vector);
+        struct point step_vector = pt_scale(direction, dist);
+        pos = pt_add(pos, step_vector);
 
         // one step taken...
         steps--;
@@ -137,7 +138,7 @@ Color march_ray(Point origin, Point direction, Scene* scene) {
     }
 }
 
-void scene_destroy(Scene scene) {
+void scene_destroy(struct scene scene) {
     for (int i = 0; i < scene.object_count; i++) {
         // free args memory
         free(scene.objects[i].args);

src/scene.h

@@ -0,0 +1,52 @@
+#pragma once
+
+#include "point.h"
+#include "camera.h"
+
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
+struct scene;
+
+// Scene objects have a position, some args, and a distance calculation function
+// the distance calc function has the following signature:
+// double distanceTo(struct point myLocation, double * myArgs, struct point externalPoint)
+// where myLocation is this.location, myArgs is this.args and externalPoint is the point from wich we want to know the distance
+// the get_color function takes args: point_hit, direction_hit, myArgs, MyLocation, MyColor
+struct scene_object {
+    struct point location;
+    double * args;
+    double (*distance)(struct point, struct scene_object *);
+    Color (*get_color)(struct point, struct point, struct scene_object *);
+    Color color;
+    struct scene* scene;
+};
+
+
+struct performance_optimization {
+    int speed_cutoff;
+    int max_steps;
+    double threshold;
+};
+
+
+struct scene {
+    unsigned int width;
+    unsigned int height;
+    struct scene_object * objects;
+    int object_count;
+    int allocated_space;
+    // performance opts
+    struct performance_optimization perf_opts;
+    // colors etc
+    Color background;
+};
+
+Image* render_scene(struct scene *scene, struct camera *camera, unsigned int threads);
+
+struct scene scene_new(unsigned int width, unsigned int height, int obj_count);
+
+void scene_add_obj(struct scene* scene, struct scene_object object);
+
+void scene_destroy(struct scene scene);