mirror of https://github.com/nmlgc/ReC98.git
50 lines
1.0 KiB
C++
50 lines
1.0 KiB
C++
// Fixed-point format for expressing world-space coordinates, with 4 bits of
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// fractional resolution.
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#pragma once
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typedef int subpixel_t;
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inline subpixel_t to_sp(float screen_v) {
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return static_cast<subpixel_t>(screen_v * 16.0f);
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}
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template <class T> class SubpixelBase {
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public:
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// Code generation will require direct access to v, if performing
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// arithmetic with a local variable...
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T v;
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void operator +=(float screen_v) {
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this->v += static_cast<T>(to_sp(screen_v));
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}
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void operator -=(float screen_v) {
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this->v -= static_cast<T>(to_sp(screen_v));
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}
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void operator =(float screen_v) {
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v = static_cast<T>(to_sp(screen_v));
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}
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T to_screen() const {
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return v >> 4;
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}
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};
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template <class T> struct SPPointBase {
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T x, y;
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void set(float screen_x, float screen_y) {
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x = screen_x;
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y = screen_y;
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}
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};
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// 16-bit (Q12.4)
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typedef SubpixelBase<subpixel_t> Subpixel;
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typedef SPPointBase<Subpixel> SPPoint;
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// 8-bit (Q4.4)
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typedef SubpixelBase<char> Subpixel8;
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typedef SPPointBase<Subpixel8> SPPoint8;
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