Mercurial > projects > ldc
view demos/ray.d @ 979:523bf4f166bc
Fix some assembler issues:
The assembler was miscompiling "add" (specifically, the "add reg/mem, imm"
variations).
The change that caused this seems to have been made because without it, some
"add"s didn't compile at all.
This patch reverts the previous change, and makes sure assembler operands are
remapped correctly even though the input operands auto-generated due to
updating operations aren't explicitly used.
author | Frits van Bommel <fvbommel wxs.nl> |
---|---|
date | Wed, 18 Feb 2009 21:46:14 +0100 |
parents | eef8ac26c66c |
children |
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line source
import tango.stdc.stdio; alias char[] string; int atoi(char[] s) { int i, fac=1; bool neg = (s.length) && (s[0] == '-'); char[] a = neg ? s[1..$] : s; foreach_reverse(c; a) { i += (c-'0') * fac; fac *= 10; } return !neg ? i : -i; } version(LDC) { pragma(intrinsic, "llvm.sqrt.f64") double sqrt(double val); } else { import tango.stdc.math; } double delta; static this() { delta=sqrt(real.epsilon); } struct Vec { double x, y, z; Vec opAdd(ref Vec other) { return Vec(x+other.x, y+other.y, z+other.z); } Vec opSub(ref Vec other) { return Vec(x-other.x, y-other.y, z-other.z); } Vec opMul(double a) { return Vec(x*a, y*a, z*a); } double dot(ref Vec other) { return x*other.x+y*other.y+z*other.z; } Vec unitise() { return opMul(1.0/sqrt(dot(*this))); } } struct Pair(T, U) { T first; U second; } typedef Pair!(double, Vec) Hit; struct Ray { Vec orig, dir; } class Scene { //abstract void intersect(ref Hit, ref Ray); void intersect(ref Hit, ref Ray) {} } class Sphere : Scene { Vec center; double radius; //mixin This!("center, radius"); this(ref Vec c, double r) { center = c; radius = r; } double ray_sphere(ref Ray ray) { auto v = center - ray.orig, b = v.dot(ray.dir), disc=b*b - v.dot(v) + radius*radius; if (disc < 0) return double.infinity; auto d = sqrt(disc), t2 = b + d; if (t2 < 0) return double.infinity; auto t1 = b - d; return (t1 > 0 ? t1 : t2); } void intersect(ref Hit hit, ref Ray ray) { auto lambda = ray_sphere(ray); if (lambda < hit.first) hit = Hit(lambda, (ray.orig + lambda*ray.dir - center).unitise); } } class Group : Scene { Sphere bound; Scene[] children; //mixin This!("bound, children"); this (Sphere s, Scene[] c) { bound = s; children = c; } void intersect(ref Hit hit, ref Ray ray) { auto l = bound.ray_sphere(ray); if (l < hit.first) foreach (child; children) child.intersect(hit, ray); } } double ray_trace(ref Vec light, ref Ray ray, Scene s) { auto hit=Hit(double.infinity, Vec(0, 0, 0)); s.intersect(hit, ray); if (hit.first == double.infinity) return 0.0; auto g = hit.second.dot(light); if (g >= 0) return 0.0; auto p = ray.orig + ray.dir*hit.first + hit.second*delta; auto hit2=Hit(double.infinity, Vec(0, 0, 0)); s.intersect(hit2, Ray(p, light*-1.0)); return (hit2.first < double.infinity ? 0 : -g); } Scene create(int level, ref Vec c, double r) { auto s = new Sphere(c, r); if (level == 1) return s; Scene[] children; children ~= s; double rn = 3*r/sqrt(12.0); for (int dz=-1; dz<=1; dz+=2) for (int dx=-1; dx<=1; dx+=2) children~=create(level-1, c + Vec(dx, 1, dz)*rn, r/2); return new Group(new Sphere(c, 3*r), children); } void main(string[] args) { int level = (args.length==3 ? args[1].atoi() : 9), n = (args.length==3 ? args[2].atoi() : 512), ss = 4; auto light = Vec(-1, -3, 2).unitise(); auto s=create(level, Vec(0, -1, 0), 1); printf("P5\n%d %d\n255\n", n,n); for (int y=n-1; y>=0; --y) for (int x=0; x<n; ++x) { double g=0; for (int d=0; d<ss*ss; ++d) { auto dir=Vec(x+(d%ss)*1.0/ss-n/2.0, y+(d/ss)*1.0/ss-n/2.0, n).unitise(); g += ray_trace(light, Ray(Vec(0, 0, -4), dir), s); } printf("%c", cast(ubyte)(0.5 + 255.0 * g / (ss*ss))); } }