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#include "svgalibscreen.h"

#include "svgalibsurface.h"

#include <QVector>

#include <QApplication>

#include <QColor>

#include <QWidget>

#include <math.h>

static int getModeDepth(vga_modeinfo *mode)

{

    const int bits = int(log2(mode->colors));

    if (bits == 24 && mode->bytesperpixel == 4)

        return 32;

    return bits;

}

//! [0]

bool SvgalibScreen::connect(const QString &displaySpec)

{

    int mode = vga_getdefaultmode();

    if (mode <= 0) {

        qCritical("SvgalibScreen::connect(): invalid vga mode");

        return false;

    }

    vga_modeinfo *modeinfo = vga_getmodeinfo(mode);

    QScreen::lstep = modeinfo->linewidth;

    QScreen::dw = QScreen::w = modeinfo->width;

    QScreen::dh = QScreen::h = modeinfo->height;

    QScreen::d = getModeDepth(modeinfo);

    QScreen::size = QScreen::lstep * dh;

    QScreen::data = 0;

    switch (depth()) {

    case 32:

        setPixelFormat(QImage::Format_ARGB32_Premultiplied);

        break;

    case 24:

        setPixelFormat(QImage::Format_RGB888);

        break;

    case 16:

        setPixelFormat(QImage::Format_RGB16);

        break;

    case 15:

        setPixelFormat(QImage::Format_RGB555);

        break;

    default:

        break;

    }

    const int dpi = 72;

    QScreen::physWidth = qRound(QScreen::dw * 25.4 / dpi);

    QScreen::physHeight = qRound(QScreen::dh * 25.4 / dpi);

    const QStringList args = displaySpec.split(QLatin1Char(':'),

                                               QString::SkipEmptyParts);

    grayscale = args.contains(QLatin1String("grayscale"), Qt::CaseInsensitive);

    return true;

}

//! [0]

void SvgalibScreen::initColorMap()

{

    const int numColors = vga_getcolors();

    if (numColors == 2 || numColors > 256) {

        screencols = 0;

        return; // not a palette based mode

    }

    if (numColors == 16) {

        if (grayscale) {

            for (int i = 0; i < 256; ++i) {

                const int c = i * 16 / 256;

                vga_setpalette(i, c, c, c);

            }

            screencols = 256; // XXX: takes advantage of optimization in alloc()

        } else { // read in EGA palette

            int r, g, b;

            for (int i = 0; i < 16; ++i) {

                vga_getpalette(i, &r, &g, &b);

                screenclut[i] = qRgb(r, g, b);

            }

            screencols = 16;

        }

        return;

    }

    Q_ASSERT(numColors == 256);

    if (grayscale) {

        for (int i = 0; i < 256; ++i) {

            const int c = i * 64 / 256;

            vga_setpalette(i, c, c, c);

        }

    } else {

        int i = 0;

#if 0

        // read in EGA palette

        while (i < 16) {

            int r, g, b;

            vga_getpalette(i, &r, &g, &b);

            screenclut[i] = qRgb(r, g, b);

            ++i;

        }

        screencols = 16;

#endif

        // 6 * 6 * 6 color cube

        for (int r = 0; r < 6; ++r) {

            for (int g = 0; g < 6; ++g) {

                for (int b = 0; b < 6; ++b) {

                    vga_setpalette(i, r * 64/6, g * 64/6, b * 64/6);

                    screenclut[i] = qRgb(r * 256/6, g * 256/6, b * 256/6);

                    ++i;

                }

            }

        }

        screencols = i;

        while (i < 256) {

            screenclut[i] = qRgb(0, 0, 0);

            ++i;

        }

    }

}

//! [1]

bool SvgalibScreen::initDevice()

{

    if (vga_init() != 0) {

        qCritical("SvgalibScreen::initDevice(): unable to initialize svgalib");

        return false;

    }

    int mode = vga_getdefaultmode();

    if (vga_setmode(mode) == -1) {

        qCritical("SvgalibScreen::initialize(): unable to set graphics mode");

        return false;

    }

    if (gl_setcontextvga(mode) != 0) {

        qCritical("SvgalibScreen::initDevice(): unable to set vga context");

        return false;

    }

    context = gl_allocatecontext();

    gl_getcontext(context);

    vga_modeinfo *modeinfo = vga_getmodeinfo(mode);

    if (modeinfo->flags & IS_LINEAR)

        QScreen::data = vga_getgraphmem();

    initColorMap();

    QScreenCursor::initSoftwareCursor();

    return true;

}

//! [1]

//! [2]

void SvgalibScreen::shutdownDevice()

{

    gl_freecontext(context);

    vga_setmode(TEXT);

}

//! [2]

//! [3]

void SvgalibScreen::disconnect()

{

}

//! [3]

//! [4]

void SvgalibScreen::solidFill(const QColor &color, const QRegion &reg)

{

    int c;

    if (depth() == 4 || depth() == 8)

        c = alloc(color.red(), color.green(), color.blue());

    else

        c = gl_rgbcolor(color.red(), color.green(), color.blue());

    const QVector<QRect> rects = (reg & region()).rects();

    for (int i = 0; i < rects.size(); ++i) {

        const QRect r = rects.at(i);

        gl_fillbox(r.left(), r.top(), r.width(), r.height(), c);

    }

}

//! [4]

void SvgalibScreen::blit16To8(const QImage &image,

                              const QPoint &topLeft, const QRegion &region)

{

    const int imageStride = image.bytesPerLine() / 2;

    const QVector<QRect> rects = region.rects();

    for (int i = 0; i < rects.size(); ++i) {

        const QRect r = rects.at(i).translated(-topLeft);

        int y = r.y();

        const quint16 *s = reinterpret_cast<const quint16*>(image.scanLine(y));

        while (y <= r.bottom()) {

            int x1 = r.x();

            while (x1 <= r.right()) {

                const quint16 c = s[x1];

                int x2 = x1;

                // find span length

                while ((x2+1 < r.right()) && (s[x2+1] == c))

                    ++x2;

                gl_hline(x1 + topLeft.x(), y + topLeft.y(), x2 + topLeft.x(),

                         qt_colorConvert<quint8, quint16>(c, 0));

                x1 = x2 + 1;

            }

            s += imageStride;

            ++y;

        }

    }

}

void SvgalibScreen::blit32To8(const QImage &image,

                              const QPoint &topLeft, const QRegion &region)

{

    const int imageStride = image.bytesPerLine() / 4;

    const QVector<QRect> rects = region.rects();

    for (int i = 0; i < rects.size(); ++i) {

        const QRect r = rects.at(i).translated(-topLeft);

        int y = r.y();

        const quint32 *s = reinterpret_cast<const quint32*>(image.scanLine(y));

        while (y <= r.bottom()) {

            int x1 = r.x();

            while (x1 <= r.right()) {

                const quint32 c = s[x1];

                int x2 = x1;

                // find span length

                while ((x2+1 < r.right()) && (s[x2+1] == c))

                    ++x2;

                gl_hline(x1 + topLeft.x(), y + topLeft.y(), x2 + topLeft.x(),

                         qt_colorConvert<quint8, quint32>(c, 0));

                x1 = x2 + 1;

            }

            s += imageStride;

            ++y;

        }

    }

}

//! [5]

void SvgalibScreen::blit(const QImage &img, const QPoint &topLeft,

                         const QRegion &reg)

{

    if (depth() == 8) {

        switch (img.format()) {

        case QImage::Format_RGB16:

            blit16To8(img, topLeft, reg);

            return;

        case QImage::Format_RGB32:

        case QImage::Format_ARGB32:

        case QImage::Format_ARGB32_Premultiplied:

            blit32To8(img, topLeft, reg);

            return;

        default:

            break;

        }

    }

    if (img.format() != pixelFormat()) {

        if (base())

            QScreen::blit(img, topLeft, reg);

        return;

    }

    const QVector<QRect> rects = (reg & region()).rects();

    for (int i = 0; i < rects.size(); ++i) {

        const QRect r = rects.at(i);

        gl_putboxpart(r.x(), r.y(), r.width(), r.height(),

                      img.width(), img.height(),

                      static_cast<void*>(const_cast<uchar*>(img.bits())),

                      r.x() - topLeft.x(), r.y() - topLeft.y());

    }

}

//! [5]

//! [7]

QWSWindowSurface* SvgalibScreen::createSurface(QWidget *widget) const

{

    if (base()) {

        static int onScreenPaint = -1;

        if (onScreenPaint == -1)

            onScreenPaint = qgetenv("QT_ONSCREEN_PAINT").toInt();

        if (onScreenPaint > 0 || widget->testAttribute(Qt::WA_PaintOnScreen))

            return new SvgalibSurface(widget);

    }

    return QScreen::createSurface(widget);

}

//! [7]

//! [8]

QWSWindowSurface* SvgalibScreen::createSurface(const QString &key) const

{

    if (key == QLatin1String("svgalib"))

        return new SvgalibSurface;

    return QScreen::createSurface(key);

}

//! [8]