#include <mbgl/geometry/icon_buffer.hpp>
#include <mbgl/platform/gl.hpp>
#include <mbgl/util/math.hpp>

#include <cmath>

namespace mbgl {

const double IconVertexBuffer::angleFactor = 128.0 / M_PI;

size_t IconVertexBuffer::add(int16_t x, int16_t y, float ox, float oy, int16_t tx, int16_t ty, float angle, float minzoom, std::array<float, 2> range, float maxzoom, float labelminzoom) {
    const size_t idx = index();
    void *data = addElement();

    int16_t *shorts = static_cast<int16_t *>(data);
    shorts[0] /* pos */ = x;
    shorts[1] /* pos */ = y;
    shorts[2] /* offset */ = std::round(ox * 64); // use 1/64 pixels for placement
    shorts[3] /* offset */ = std::round(oy * 64);

    uint8_t *ubytes = static_cast<uint8_t *>(data);
    ubytes[8] /* labelminzoom */ = labelminzoom * 10;
    ubytes[9] /* minzoom */ =  minzoom * 10; // 1/10 zoom levels: z16 == 160.
    ubytes[10] /* maxzoom */ = std::fmin(maxzoom, 25) * 10; // 1/10 zoom levels: z16 == 160.
    ubytes[11] /* angle */ = (int16_t)std::round(angle * angleFactor) % 256;
    ubytes[12] /* rangeend */ = util::max((int16_t)std::round(range[0] * angleFactor), (int16_t)0) % 256;
    ubytes[13] /* rangestart */ = util::min((int16_t)std::round(range[1] * angleFactor), (int16_t)255) % 256;

    shorts[8] /* tex */ = tx;
    shorts[9] /* tex */ = ty;

    return idx;
}

}