diff options
| -rw-r--r-- | .gitignore | 1 | ||||
| -rw-r--r-- | LICENCE | 13 | ||||
| -rw-r--r-- | Makefile | 24 | ||||
| -rw-r--r-- | ray.c | 177 |
4 files changed, 215 insertions, 0 deletions
diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..e027563 --- /dev/null +++ b/.gitignore @@ -0,0 +1 @@ +ray @@ -0,0 +1,13 @@ +Copyright (c) 2010, Martin Stensgård <mastensg@ping.uio.no>. + +Permission to use, copy, modify, and distribute this software for any +purpose with or without fee is hereby granted, provided that the above +copyright notice and this permission notice appear in all copies. + +THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR +ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF +OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..892125d --- /dev/null +++ b/Makefile @@ -0,0 +1,24 @@ +DEBUG = -O0 -ggdb -g3 +DEBUG = -O3 +CFLAGS = -Wall -pedantic -std=gnu99 $(DEBUG) +LDFLAGS = -lGL -lGLU -lglut +BINARY = ray +VERSION = 0.1 +PREFIX = /usr/local +OBJECTS = $(BINARY).o + +all: $(BINARY) + +clean: + rm -f $(BINARY).o $(BINARY) + +install: all + mkdir -p $(PREFIX)/bin + cp -f $(BINARY) $(PREFIX)/bin/$(BINARY) + chmod 755 $(PREFIX)/bin/$(BINARY) + mkdir -p $(PREFIX)/man/man1 + sed "s/VERSION/$(VERSION)/g" < $(BINARY).1 > $(PREFIX)/man/man1/$(BINARY).1 + chmod 644 $(PREFIX)/man/man1/$(BINARY).1 + +uninstall: + rm -f $(BINARY) $(PREFIX)/bin/$(BINARY) @@ -0,0 +1,177 @@ +#include <GL/gl.h> +#include <GL/glu.h> +#include <GL/glut.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <math.h> + +#define WIDTH 1080 +#define HEIGHT 1080 +#define BUFFER_SIZE (WIDTH * HEIGHT * 4) + +#define LENGTH(array) (sizeof(array) / sizeof(array[0])) +#define MAX(x, y) (x > y ? x : y) +#define MIN(x, y) (x < y ? x : y) +#define POW2(x) ((x) * (x)) +#define POW3(x) ((x) * (x) * (x)) +#define POW4(x) ((x) * (x) * (x) * (x)) +#define POW5(x) ((x) * (x) * (x) * (x) * (x)) + +typedef struct { + float position[3]; + float radius; + float diffuse[3]; +} Object; + +typedef struct { + float position[3]; + float diffuse[3]; +} Light; + +static Object objects[2] = {{.position={1.5, 0, -20}, .radius=.1, .diffuse={0, 0, .3}}, + {.position={-1.5, 0, -30}, .radius=.1, .diffuse={0, 0, .3}}}; +static Light lights[1] = {{.position={0, 2, -4}, .diffuse={0, .7, .7}}}; +static unsigned char buffer[BUFFER_SIZE]; + +static float +dot(float x[3], float y[3]) { + return x[0] * y[0] + x[1] * y[1] + x[2] * y[2]; +} + +static void +normalize(float x[3]) { + float len; + int i; + + len = sqrt(dot(x, x)); + + for(i = 0; i < 3; ++i) + x[i] /= len; +} + +static void +trace(float s[3], float d[3], float pixel[3], int N) { + int i, j; + float D; + float l[3]; + float n[3]; + float t; + float v[3]; + float vd, vv; + float y[3]; + Object *object = objects; + Light *light = lights; + + for(j = 0; j < LENGTH(objects); ++j) { + object = &objects[j]; + + for(i = 0; i < 3; ++i) + v[i] = s[i] - object->position[i]; + + vd = dot(v, d); + vv = dot(v, v); + + D = POW2(2 * vd) - 4 * (vv - POW2(object->radius)); + + if(D < 0) { + pixel[0] += .3; + pixel[1] += .15; + pixel[2] += .075; + } else { + + t = MIN(-vd + sqrt(D), -vd - sqrt(D)); + + for(i = 0; i < 3; ++i) { + y[i] = s[i] + t * d[i]; + n[i] = y[i] - object->position[i]; + l[i] = light->position[i] - object->position[i]; + } + + normalize(n); + normalize(l); + + for(i = 0; i < 3; ++i) { + n[i] = (object->diffuse[i] + light->diffuse[i]) * dot(n, l); + //n[i] = object->diffuse[i]; + pixel[i] += n[i]; + } + + if(N) + trace(y, n, pixel, N - 1); + } + } +} + +static void +display(void) { + int i, j; + float x, y; + float s[3] = {0, 0, 1}; + float d[3]; + float pixel[3]; + + memset(buffer, '\0', sizeof(buffer)); + + for(i = 0; i < BUFFER_SIZE; i += 4) { + x = (i / 4) % WIDTH - WIDTH / 2; + y = (i / 4) / WIDTH - HEIGHT / 2; + + d[0] = x / (WIDTH / 2); + d[1] = y / (HEIGHT / 2); + d[2] = -1; + + memset(pixel, '\0', sizeof(pixel)); + trace(s, d, pixel, 0); + + //printf("%f %f %f\n", pixel[0], pixel[1], pixel[2]); + + for(j = 0; j < 3; ++j) + buffer[i + j] = MIN(255 * pixel[j], 255); + } + + glDrawPixels(WIDTH, HEIGHT, GL_BGRA, GL_UNSIGNED_BYTE, buffer); + + glutSwapBuffers(); +} + +static void +reshape(int w, int h) { + glViewport(0, 0, w, h); +} + +static void +keyboard(unsigned char key, int x, int y) { + if (key == 27) + exit(0); +} + +static int +init(int argc, char **argv, int w, int h) { + glutInit(&argc, argv); + + glutInitWindowPosition(0, 0); + glutInitWindowSize(w, h); + glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA); + glutCreateWindow(argv[0]); + + glDepthMask(0); + glDisable(GL_DEPTH_TEST); + glDisable(GL_BLEND); + + return 0; +} + +int +main(int argc, char **argv) { + if (init(argc, argv, WIDTH, HEIGHT)) + return 1; + + glutDisplayFunc(display); + glutReshapeFunc(reshape); + glutKeyboardFunc(keyboard); + + glutMainLoop(); + + return 0; +} |