gp_dpi.h

// SPDX-License-Identifier: LGPL-2.1-or-later
/*
 * Copyright (C) 2023 Cyril Hrubis <metan@ucw.cz>
 */
 
#ifndef BACKENDS_GP_DPI_H
#define BACKENDS_GP_DPI_H
 
#include <core/gp_debug.h>
 
static inline unsigned int gp_dpi_from_size(unsigned int w, unsigned int w_mm,
                                            unsigned int h, unsigned int h_mm)
{
        unsigned int dpi = ((w * 25.4) / w_mm + (h * 25.4) / h_mm + 1)/2;
 
        GP_DEBUG(1, "Resolution %ux%u - %ummx%umm - dpi %u", w, h, w_mm, h_mm, dpi);
 
        return dpi;
}
 
static inline float gp_dpi_to_ppmm(unsigned int dpi)
{
        return dpi / 25.4;
}
 
static inline gp_size gp_dpi_mm_to_px(unsigned int dpi, float mm)
{
        return gp_dpi_to_ppmm(dpi) * mm + 0.5;
}
 
#endif /* BACKENDS_GP_DPI_H */