#include "engine/pixel.h"

#include <algorithm>

#include "engine/math.h"

uint32_t ShadeColor(uint32_t c, float k)
{
    const float r = Clampf(float(c & 0xFF) * k, 0.0f, 255.0f);
    const float g = Clampf(float((c >> 8) & 0xFF) * k, 0.0f, 255.0f);
    const float b = Clampf(float((c >> 16) & 0xFF) * k, 0.0f, 255.0f);
    return RGBA(uint8_t(r), uint8_t(g), uint8_t(b), AlphaOf(c));
}

void DiamondRowN(int y, int dw, int dh, int& x0, int& x1)
{
    const int half = std::max(1, dh / 2);
    const int k = (y < half) ? y : (dh - 1 - y);
    const int width = std::max(1, (dw / half) * (k + 1));
    x0 = (dw - width) / 2;
    x1 = x0 + width;
}

void OutlineSilhouette(Sprite& s, uint32_t outline)
{
    Sprite copy = s;
    for (int y = 0; y < s.h; ++y)
    {
        for (int x = 0; x < s.w; ++x)
        {
            if (AlphaOf(copy.Get(x, y)) == 0) continue;
            const bool border =
                x == 0 || y == 0 || x == s.w - 1 || y == s.h - 1 ||
                AlphaOf(copy.Get(x - 1, y)) == 0 || AlphaOf(copy.Get(x + 1, y)) == 0 ||
                AlphaOf(copy.Get(x, y - 1)) == 0 || AlphaOf(copy.Get(x, y + 1)) == 0;
            if (border) s.Set(x, y, outline);
        }
    }
}