/*
 * UCIMF - Unicode Console InputMethod Framework                                                    
 *
 * Copyright (c) 2007 Chun-Yu Lee (Mat) and Open RazzmatazZ Laboratory (OrzLab)
 *                                                                                                  
 * Parts taken from zhcon project.
 * Copyright (c) 2001 rick <rick@chinaren.com>
 *                    huyong <ccpaging@online.sh.cn>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif


#ifdef USING_VGA
#if defined(linux)

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/io.h>
#include <cassert>
#include "debug.h"
#include "vgadev.h"
#include "lrmi.h"

#define GRAPH_BASE 0xA0000
#define GRAPH_ADDR  0x3ce
#define GRAPH_DATA  0x3cf

char *VGADev::mpBuf = NULL;
int VGADev::mBufLen = 0;
unsigned long VGADev::mNextLine = 0; // offset to one line below
int VGADev::mFd = -1;

bool VGADev::TryOpen() {
    if (!LRMI_init()) {
        throw (runtime_error("LRMI_init() failed.\n"));
        return false;
    }

    EnableIOPerm();
    if (!SetVideoMode(0x12)) {
        DisableIOPerm();
        throw (runtime_error("LRMI_int() failed, can't change video mode.\n"));
        return false;
    }

    if ((mFd = open("/dev/mem", O_RDWR)) < 0) {
        DisableIOPerm();
        throw(runtime_error("Cannot open /dev/mem.\n"));
        return false;
    }

    mXres = 640;
    mYres = 480;
    mBufLen = mXres * mYres / 8;
    mpBuf = static_cast<char *>(mmap((__ptr_t)0, mBufLen, PROT_READ | PROT_WRITE, MAP_SHARED,
                                mFd, GRAPH_BASE));
    if (mpBuf == MAP_FAILED) {
        DisableIOPerm();
        throw(runtime_error("mmap() failed!"));
    }

    mpGraphDev = new VGADev;
    return true;
}

VGADev::VGADev() {
    mNextLine = mXres >> 3;
    EnableIOPerm();
    SetDefaultMode();
}

VGADev::~VGADev() {
    if (mpBuf != NULL)
        munmap(mpBuf, mBufLen);
    if (mFd >= 0)
        close(mFd);
    SetVideoMode(0x3);
    DisableIOPerm();
}

void VGADev::EnableIOPerm()
{
    ioperm(GRAPH_ADDR, 1, 1);
    ioperm(GRAPH_DATA, 1, 1);
    ioperm(0, 0x400, 1);
    iopl(3);
}

void VGADev::DisableIOPerm()
{
    ioperm(GRAPH_ADDR, 1, 0);
    ioperm(GRAPH_DATA, 1, 0);
    ioperm(0, 0x400, 0);
    iopl(3);
}

inline bool VGADev::SetVideoMode(int mode)
{
    struct LRMI_regs r;
    memset(&r, 0, sizeof(r));
    r.eax = mode;
    return LRMI_int(0x10, &r);
}

inline void VGADev::SetDefaultMode() {
    SetWriteMode(3);
    SetOper(0);
    SetBitMask(0xff);
}

inline void VGADev::SetBitMask(char mask) {
    outb(9, GRAPH_ADDR);
    outb(mask, GRAPH_DATA);
}

inline void VGADev::SetOper(int op) {
    outb(3, GRAPH_ADDR);
    outb(op, GRAPH_DATA);
}

inline void VGADev::SetWriteMode(int mode) {
    outb(5, GRAPH_ADDR);
    outb(mode, GRAPH_DATA);
}

inline void VGADev::SetColor(int color) {
    outb(0, GRAPH_ADDR);
    outb(color, GRAPH_DATA);
}

void VGADev::PutPixel(int x,int y,int color) {
    static int prevColor = -1;
    if (prevColor != color) {
        prevColor = color;
        SetColor(color);
    }

    __u8* dest = (__u8*)mpBuf + mNextLine * y + (x>>3);
    fb_readb(dest);
    *dest = 0x80 >> (x & 7);
}

void VGADev::FillRect(int x1,int y1,int x2,int y2,int color) {
    assert( x1 >= 0 && x1 < mXres && y1 >=0 && y1 < mYres);
    assert( x2 >= 0 && x2 < mXres && y2 >=0 && y2 < mYres);
    assert(x1 <= x2 && y1 <= y2);

#ifndef NDEBUG
    //debug<<"FillRect ("<<x1<<","<<y1<<")-("<<x2<<","<<y2<<")"<<endl;
#endif
    SetColor(color);

    __u8* destorig = (__u8*)mpBuf + mNextLine * y1 + (x1>>3);
    __u8* dest = destorig;

    int width = x2 - x1 + 1;
    int left, right, midbytes;
    left = 8 - (x1 & 7);
    // left maybe 8
    if (left == 8) left = 0;

    if (left >= width) {
        right = 0;
        midbytes = 0;
    } else {
        right = (x1 + width) & 7;
        midbytes = (width - left - right) / 8;
    }
#ifndef NDEBUG
    if (left + right > width || midbytes < 0) {
        debug<<"FillRect x1="<<x1<<" width="<<width<<" left="<<left;
        debug<<" midbytes="<<midbytes<<" right="<<right<<endl;
    }
#endif
    
    int height;
    if (left) {
        __u8 leftmask = 0xff >> (8 - left);
        if (left > width) leftmask &= 0xff << (left - width);
        for (height = y2 - y1 + 1; height--; dest += mNextLine) {
            fb_readb(dest); // fill latches
            *dest = leftmask;
        }
        destorig++;
    }
    if (midbytes) {
        dest = destorig;
        for (height = y2 - y1 + 1; height--; dest += mNextLine) {
            memset(dest, 0xff, midbytes);
        }
        destorig += midbytes;
    }
    if (right) {
        dest = destorig;
        __u8 rightmask = 0xff << (8 - right);
        for (height = y2 - y1 + 1; height--; dest += mNextLine) {
            fb_readb(dest); // fill latches
            *dest = rightmask;
        }
    }
}

void VGADev::RevRect(int x1,int y1,int x2,int y2) {
    assert( x1 >= 0 && x1 < Width() && y1 >=0 && y1 < Height());
    assert( x2 >= 0 && x2 < Width() && y2 >=0 && y2 < Height());
    assert(x1 <= x2 && y1 <= y2);

    __u8* dest = (__u8*)mpBuf + mNextLine * y1 + (x1>>3);
    __u8* dest8;

    SetWriteMode(3);
    SetOper(0x18);
    SetColor(0xf);
    SetBitMask(0xff);
    
    int width = x2 - x1 + 1;
    int left, right, midbytes;
    left = 8 - (x1 & 7);
    // left maybe 8
    if (left == 8) left = 0;

    if (left >= width) {
        right = 0;
        midbytes = 0;
    } else {
        right = (x1 + width) & 7;
        midbytes = (width - left - right) / 8;
    }

    __u8 leftmask = 0xff >> (8 - left);
    if (left > width) leftmask &= 0xff << (left - width);
    __u8 rightmask = 0xff << (8 - right);
    int cnt;
    for(int height = y2 - y1 + 1; height--; dest += mNextLine) {
        dest8 = dest;
        if (left) {
            fb_readb(dest8);
            fb_writeb(leftmask, dest8++);
        }
        if (midbytes) {
            for(cnt = midbytes; cnt--; ) {
                fb_readb(dest8);
                fb_writeb(0xff, dest8++);
            }
        }
        if (right) {
            fb_readb(dest8);
            fb_writeb(rightmask, dest8);
        }
    }
    SetDefaultMode();
}

void VGADev::SwitchToGraph() {
    SetVideoMode(0x12);
    SetDefaultMode();
}

void VGADev::SwitchToText() {
    SetVideoMode(0x3);
}
#endif

#endif //USING_VGA