/*
 * Copyright 2021, Haiku, Inc.
 * Distributed under the terms of the MIT License.
 */


#include "graphics.h"


RasBuf32 gFramebuf = {NULL, 0, 0, 0};


void
Clear(RasBuf32 vb, uint32_t c)
{
        vb.stride -= vb.width;
        for (; vb.height > 0; vb.height--) {
                for (int x = 0; x < vb.width; x++) {
                        *vb.colors = c;
                        vb.colors++;
                }
                vb.colors += vb.stride;
        }
}


template <typename Color>
RasBuf<Color>
RasBuf<Color>::Clip(int x, int y, int w, int h) const
{
        RasBuf<Color> vb = *this;
        if (x < 0) {w += x; x = 0;}
        if (y < 0) {h += y; y = 0;}
        if (x + w > vb.width) {w = vb.width - x;}
        if (y + h > vb.height) {h = vb.height - y;}
        if (w > 0 && h > 0) {
                vb.colors += y*vb.stride + x;
                vb.width = w;
                vb.height = h;
        } else {
                vb.colors = 0;
                vb.width = 0;
                vb.height = 0;
        }
        return vb;
}

template class RasBuf<uint8>;
template class RasBuf<uint32>;


RasBuf8
Font::ThisGlyph(uint32 ch)
{
        if (ch < firstChar || ch >= firstChar + charCnt)
                return ThisGlyph(' ');

        RasBuf8 rb;
        rb.colors = data + (ch - firstChar) * charWidth * charHeight;
        rb.stride = charWidth;
        rb.width = charWidth;
        rb.height = charHeight;
        return rb;
}


void
BlitMaskRgb(RasBuf32 dst, RasBuf8 src, int32 x, int32 y, uint32_t c)
{
        int dstW, dstH;
        uint32_t dc, a;
        dstW = dst.width; dstH = dst.height;
        dst = dst.Clip(x, y, src.width, src.height);
        src = src.Clip(-x, -y, dstW, dstH);
        dst.stride -= dst.width;
        src.stride -= src.width;
        for (; dst.height > 0; dst.height--) {
                for (x = dst.width; x > 0; x--) {
                        dc = *dst.colors;
                        a = *src.colors;
                        if (a != 0) {
                                *dst.colors =
                                          ((((dc >>  0) % 0x100) * (0xff - a) / 0xff
                                                + ((c >>  0) % 0x100) * a / 0xff) <<  0)
                                        + ((((dc >>  8) % 0x100) * (0xff - a) / 0xff
                                                + ((c >>  8) % 0x100) * a / 0xff) <<  8)
                                        + ((((dc >> 16) % 0x100) * (0xff - a) / 0xff
                                                + ((c >> 16) % 0x100) * a / 0xff) << 16)
                                        + (dc & 0xff000000);
                        }
                        dst.colors++;
                        src.colors++;
                }
                dst.colors += dst.stride;
                src.colors += src.stride;
        }
}