41 lines
1.3 KiB
D
41 lines
1.3 KiB
D
import std.stdio, std.math, std.algorithm, std.numeric;
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alias V3 = double[3];
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immutable light = normalize([30.0, 30.0, -50.0]);
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V3 normalize(V3 v) pure @nogc {
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v[] /= dotProduct(v, v) ^^ 0.5;
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return v;
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}
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double dot(in ref V3 x, in ref V3 y) pure nothrow @nogc {
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immutable double d = dotProduct(x, y);
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return d < 0 ? -d : 0;
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}
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void drawSphere(in double R, in double k, in double ambient) @nogc {
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enum shades = ".:!*oe&#%@";
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foreach (immutable i; cast(int)floor(-R) .. cast(int)ceil(R) + 1) {
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immutable double x = i + 0.5;
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foreach (immutable j; cast(int)floor(-2 * R) ..
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cast(int)ceil(2 * R) + 1) {
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immutable double y = j / 2. + 0.5;
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if (x ^^ 2 + y ^^ 2 <= R ^^ 2) {
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immutable vec = [x, y, (R^^2 - x^^2 - y^^2) ^^ 0.5]
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.normalize;
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immutable double b = dot(light, vec) ^^ k + ambient;
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int intensity = cast(int)((1 - b) * (shades.length-1));
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intensity = min(shades.length - 1, max(intensity, 0));
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shades[intensity].putchar;
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} else
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' '.putchar;
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}
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'\n'.putchar;
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}
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}
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void main() {
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drawSphere(20, 4, 0.1);
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drawSphere(10, 2, 0.4);
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}
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