commit cc544ca3d56234599f71a2a9973ee2d13dd30840
parent 209564e16cebbd4dfd05f3cc910daf9b7242edf4
Author: Pavel Renev <an2qzavok@gmail.com>
Date: Mon, 15 Mar 2021 08:25:01 +0000
render: testbed for raytracing code
Diffstat:
| M | mkfile | | | 2 | +- |
| A | render.c | | | 91 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
2 files changed, 92 insertions(+), 1 deletion(-)
diff --git a/mkfile b/mkfile
@@ -1,6 +1,6 @@
</$objtype/mkfile
-TARG=fs node
+TARG=fs node render
OFILES=
HFILE=octree.h
BIN=/$objtype/bin/octree
diff --git a/render.c b/render.c
@@ -0,0 +1,90 @@
+#include <u.h>
+#include <libc.h>
+
+#include "octree.h"
+
+typedef struct Pixel Pixel;
+typedef struct Dot Dot;
+typedef struct Rad Rad;
+typedef struct Ray Ray;
+
+struct Pixel {
+ double r;
+ double g;
+ double b;
+};
+
+struct Dot {
+ double x;
+ double y;
+ double z;
+};
+
+struct Rad {
+ double u;
+ double v;
+ double z;
+};
+
+struct Ray {
+ Dot pos;
+ Rad dir;
+};
+
+Pixel Pwhite = {1, 1, 1};
+Pixel Pblack = {0, 0, 0};
+
+Ray sphere = {{0.5, 0.5, 0}, {0, 0, 0.5}};
+
+int
+spherehit(Ray v, Ray s)
+{
+ return (hypot(v.pos.x -s.pos.x, v.pos.y - s.pos.y) <= s.dir.z);
+}
+
+Pixel
+ray(Ray v)
+{
+ Pixel p = {
+ .r = (v.pos.x + v.pos.y)/2,
+ .g = 0,
+ .b = 0,
+ };
+ if (spherehit(v, sphere)) {
+ p = Pblack;
+ }
+ return p;
+}
+
+int
+render(int x, int y)
+{
+ Pixel p;
+ int r, g, b;
+ Ray v;
+ v.pos = (Dot){ (double)x/256.0, (double)y/256.0, 0 };
+ p = ray(v);
+ r = 0xff * p.r;
+ g = 0xff * p.g;
+ b = 0xff * p.b;
+ return (r<<16)|(g<<8)|b;
+}
+
+void
+main(void)
+{
+ int i, x, y;
+ int buf[256*256];
+ write(1, " x8r8g8b8 ", 12);
+ write(1, " 0 ", 12);
+ write(1, " 0 ", 12);
+ write(1, " 256 ", 12);
+ write(1, " 256 ", 12);
+ for (i = 0; i < 256 * 256; i++) {
+ x = i%256;
+ y = 255-(i/256);
+ buf[i] = render(x, y);
+ }
+ write(1, buf, 4 * 256 * 256);
+ exits(nil);
+}
+\ No newline at end of file
