graphics.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef ADL_GRAPHICS_H
#define ADL_GRAPHICS_H

#include "common/rect.h"
#include "common/stream.h"

#include "adl/display.h"

namespace Adl {

class GraphicsMan {
public:
    virtual ~GraphicsMan() { }

    // Applesoft BASIC HLINE
    virtual void drawLine(const Common::Point &p1, const Common::Point &p2, byte color) const = 0;
    // Applesoft BASIC DRAW
    virtual void drawShape(Common::ReadStream &shape, Common::Point &pos, byte rotation = 0, byte scaling = 1, byte color = 0x7f) const = 0;
    virtual void drawPic(Common::SeekableReadStream &pic, const Common::Point &pos) = 0;
    virtual void clearScreen() const = 0;
    void setBounds(const Common::Rect &r) { _bounds = r; }

protected:
    Common::Rect _bounds;
};

// Used in hires1
template <class T>
class GraphicsMan_v1 : public GraphicsMan {
public:
    GraphicsMan_v1(T &display) : _display(display) { this->setBounds(Common::Rect(280, 160)); }

    void drawLine(const Common::Point &p1, const Common::Point &p2, byte color) const override;
    void drawShape(Common::ReadStream &shape, Common::Point &pos, byte rotation = 0, byte scaling = 1, byte color = 0x7f) const override;
    void drawPic(Common::SeekableReadStream &pic, const Common::Point &pos) override;
    void clearScreen() const override;

protected:
    T &_display;
    void putPixel(const Common::Point &p, byte color) const;

private:
    void drawShapePixel(Common::Point &p, byte color, byte bits, byte quadrant) const;
    virtual byte getClearColor() const { return 0x00; }
};

// Used in hires0 and hires2-hires4
template <class T>
class GraphicsMan_v2 : public GraphicsMan_v1<T> {
public:
    GraphicsMan_v2(T &display) : GraphicsMan_v1<T>(display), _color(0) { }
    void drawPic(Common::SeekableReadStream &pic, const Common::Point &pos) override;

protected:
    bool canFillAt(const Common::Point &p, const bool stopBit = false);
    void fillRow(Common::Point p, const byte pattern, const bool stopBit = false);
    byte getPatternColor(const Common::Point &p, byte pattern);

private:
    static bool readByte(Common::SeekableReadStream &pic, byte &b);
    bool readPoint(Common::SeekableReadStream &pic, Common::Point &p);
    void drawCorners(Common::SeekableReadStream &pic, bool yFirst);
    void drawRelativeLines(Common::SeekableReadStream &pic);
    void drawAbsoluteLines(Common::SeekableReadStream &pic);
    void fill(Common::SeekableReadStream &pic);
    virtual void fillRowLeft(Common::Point p, const byte pattern, const bool stopBit);
    virtual void fillAt(Common::Point p, const byte pattern);
    byte getClearColor() const override { return 0xff; }

    byte _color;
    Common::Point _offset;
};

// Used in hires5, hires6 and gelfling (possibly others as well)
template <class T>
class GraphicsMan_v3 : public GraphicsMan_v2<T> {
public:
    GraphicsMan_v3(T &display) : GraphicsMan_v2<T>(display) { }

private:
    void fillRowLeft(Common::Point p, const byte pattern, const bool stopBit) override;
    void fillAt(Common::Point p, const byte pattern) override;
};

template <class T>
void GraphicsMan_v1<T>::clearScreen() const {
    _display.setMode(Display::kModeMixed);
    _display.clear(getClearColor());
}

// Draws a four-connected line
template <class T>
void GraphicsMan_v1<T>::drawLine(const Common::Point &p1, const Common::Point &p2, byte color) const {
    int16 deltaX = p2.x - p1.x;
    int8 xStep = 1;

    if (deltaX < 0) {
        deltaX = -deltaX;
        xStep = -1;
    }

    int16 deltaY = p2.y - p1.y;
    int8 yStep = -1;

    if (deltaY > 0) {
        deltaY = -deltaY;
        yStep = 1;
    }

    Common::Point p(p1);
    int16 steps = deltaX - deltaY + 1;
    int16 err = deltaX + deltaY;

    while (true) {
        putPixel(p, color);

        if (--steps == 0)
            return;

        if (err < 0) {
            p.y += yStep;
            err += deltaX;
        } else {
            p.x += xStep;
            err += deltaY;
        }
    }
}

template <class T>
void GraphicsMan_v1<T>::putPixel(const Common::Point &p, byte color) const {
    if (this->_bounds.contains(p))
        _display.putPixel(p, color);
}

template <class T>
void GraphicsMan_v1<T>::drawShapePixel(Common::Point &p, byte color, byte bits, byte quadrant) const {
    if (bits & 4)
        putPixel(p, color);

    bits += quadrant;

    if (bits & 1)
        p.x += (bits & 2 ? -1 : 1);
    else
        p.y += (bits & 2 ? 1 : -1);
}

template <class T>
void GraphicsMan_v1<T>::drawShape(Common::ReadStream &corners, Common::Point &pos, byte rotation, byte scaling, byte color) const {
    const byte stepping[] = {
        0xff, 0xfe, 0xfa, 0xf4, 0xec, 0xe1, 0xd4, 0xc5,
        0xb4, 0xa1, 0x8d, 0x78, 0x61, 0x49, 0x31, 0x18,
        0xff
    };

    byte quadrant = rotation >> 4;
    rotation &= 0xf;
    byte xStep = stepping[rotation];
    byte yStep = stepping[(rotation ^ 0xf) + 1] + 1;

    while (true) {
        byte b = corners.readByte();

        if (corners.eos() || corners.err())
            error("Error reading corners");

        if (b == 0)
            return;

        do {
            byte xFrac = 0x80;
            byte yFrac = 0x80;
            for (uint j = 0; j < scaling; ++j) {
                if (xFrac + xStep + 1 > 255)
                    drawShapePixel(pos, color, b, quadrant);
                xFrac += xStep + 1;
                if (yFrac + yStep > 255)
                    drawShapePixel(pos, color, b, quadrant + 1);
                yFrac += yStep;
            }
            b >>= 3;
        } while (b != 0);
    }
}

template <class T>
void GraphicsMan_v1<T>::drawPic(Common::SeekableReadStream &pic, const Common::Point &pos) {
    byte x, y;
    bool bNewLine = false;
    byte oldX = 0, oldY = 0;
    while (1) {
        x = pic.readByte();
        y = pic.readByte();

        if (pic.err() || pic.eos())
            error("Error reading picture");

        if (x == 0xff && y == 0xff)
            return;

        if (x == 0 && y == 0) {
            bNewLine = true;
            continue;
        }

        x += pos.x;
        y += pos.y;

        if (y > 160)
            y = 160;

        if (bNewLine) {
            putPixel(Common::Point(x, y), 0x7f);
            bNewLine = false;
        } else {
            drawLine(Common::Point(oldX, oldY), Common::Point(x, y), 0x7f);
        }

        oldX = x;
        oldY = y;
    }
}

template <class T>
bool GraphicsMan_v2<T>::readByte(Common::SeekableReadStream &pic, byte &b) {
    b = pic.readByte();

    if (pic.eos() || pic.err())
        error("Error reading picture");

    if (b >= 0xe0) {
        pic.seek(-1, SEEK_CUR);
        return false;
    }

    return true;
}

template <class T>
bool GraphicsMan_v2<T>::readPoint(Common::SeekableReadStream &pic, Common::Point &p) {
    byte b;

    if (!readByte(pic, b))
        return false;

    p.x = b + _offset.x;
    p.x <<= 1;

    if (!readByte(pic, b))
        return false;

    p.y = b + _offset.y;

    return true;
}

template <class T>
byte GraphicsMan_v2<T>::getPatternColor(const Common::Point &p, byte pattern) {
    const byte fillPatterns[][4] = {
        { 0x00, 0x00, 0x00, 0x00 },
        { 0x80, 0x80, 0x80, 0x80 },
        { 0xff, 0xff, 0xff, 0xff },
        { 0x7f, 0x7f, 0x7f, 0x7f },
        { 0x2a, 0x55, 0x2a, 0x55 },
        { 0xaa, 0xd5, 0xaa, 0xd5 },
        { 0x55, 0x2a, 0x55, 0x2a },
        { 0xd5, 0xaa, 0xd5, 0xaa },
        { 0x33, 0x66, 0x4c, 0x19 },
        { 0xb3, 0xe6, 0xcc, 0x99 },
        { 0x22, 0x44, 0x08, 0x11 },
        { 0xa2, 0xc4, 0x88, 0x91 },
        { 0x11, 0x22, 0x44, 0x08 },
        { 0x91, 0xa2, 0xc4, 0x88 },
        { 0x6e, 0x5d, 0x3b, 0x77 },
        { 0xee, 0xdd, 0xbb, 0xf7 },
        { 0x5d, 0x3b, 0x77, 0x6e },
        { 0xdd, 0xbb, 0xf7, 0xee },
        { 0x66, 0x4c, 0x19, 0x33 },
        { 0xe6, 0xcc, 0x99, 0xb3 },
        { 0x33, 0x66, 0x4c, 0x19 },
        { 0xb3, 0xe6, 0xcc, 0x99 }
    };

    if (pattern >= ARRAYSIZE(fillPatterns))
        error("Invalid fill pattern %i encountered in picture", pattern);

    byte offset = (p.y & 1) << 1;
    offset += (p.x / 7) & 3;

    return fillPatterns[pattern][offset % sizeof(fillPatterns[0])];
}

template <class T>
void GraphicsMan_v2<T>::drawCorners(Common::SeekableReadStream &pic, bool yFirst) {
    Common::Point p;

    if (!readPoint(pic, p))
        return;

    if (yFirst)
        goto doYStep;

    while (true) {
        byte b;
        int16 n;

        if (!readByte(pic, b))
            return;

        n = b + _offset.x;

        this->putPixel(p, _color);

        n <<= 1;
        this->drawLine(p, Common::Point(n, p.y), _color);
        p.x = n;

doYStep:
        if (!readByte(pic, b))
            return;

        n = b + _offset.y;

        this->putPixel(p, _color);
        this->drawLine(p, Common::Point(p.x, n), _color);

        this->putPixel(Common::Point(p.x + 1, p.y), _color);
        this->drawLine(Common::Point(p.x + 1, p.y), Common::Point(p.x + 1, n), _color);

        p.y = n;
    }
}

template <class T>
void GraphicsMan_v2<T>::drawRelativeLines(Common::SeekableReadStream &pic) {
    Common::Point p1;

    if (!readPoint(pic, p1))
        return;

    this->putPixel(p1, _color);

    while (true) {
        Common::Point p2(p1);

        byte n;

        if (!readByte(pic, n))
            return;

        byte h = (n & 0x70) >> 4;
        byte l = n & 7;

        if (n & 0x80)
            p2.x -= (h << 1);
        else
            p2.x += (h << 1);

        if (n & 8)
            p2.y -= l;
        else
            p2.y += l;

        this->drawLine(p1, p2, _color);
        p1 = p2;
    }
}

template <class T>
void GraphicsMan_v2<T>::drawAbsoluteLines(Common::SeekableReadStream &pic) {
    Common::Point p1;

    if (!readPoint(pic, p1))
        return;

    this->putPixel(p1, _color);

    while (true) {
        Common::Point p2;

        if (!readPoint(pic, p2))
            return;

        this->drawLine(p1, p2, _color);
        p1 = p2;
    }
}

template <class T>
bool GraphicsMan_v2<T>::canFillAt(const Common::Point &p, const bool stopBit) {
    return this->_display.getPixelBit(p) != stopBit && this->_display.getPixelBit(Common::Point(p.x + 1, p.y)) != stopBit;
}

template <class T>
void GraphicsMan_v2<T>::fillRowLeft(Common::Point p, const byte pattern, const bool stopBit) {
    byte color = getPatternColor(p, pattern);

    while (--p.x >= this->_bounds.left) {
        if ((p.x % 7) == 6) {
            color = getPatternColor(p, pattern);
            this->_display.setPixelPalette(p, color);
        }
        if (this->_display.getPixelBit(p) == stopBit)
            break;
        this->_display.setPixelBit(p, color);
    }
}

template <class T>
void GraphicsMan_v2<T>::fillRow(Common::Point p, const byte pattern, const bool stopBit) {
    // Set pixel at p and palette
    byte color = getPatternColor(p, pattern);
    this->_display.setPixelPalette(p, color);
    this->_display.setPixelBit(p, color);

    // Fill left of p
    fillRowLeft(p, pattern, stopBit);

    // Fill right of p
    while (++p.x < this->_bounds.right) {
        if ((p.x % 7) == 0) {
            color = getPatternColor(p, pattern);
            // Palette is set before the first bit is tested
            this->_display.setPixelPalette(p, color);
        }
        if (this->_display.getPixelBit(p) == stopBit)
            break;
        this->_display.setPixelBit(p, color);
    }
}

template <class T>
void GraphicsMan_v2<T>::fillAt(Common::Point p, const byte pattern) {
    const bool stopBit = !this->_display.getPixelBit(p);

    // Move up into the open space above p
    while (--p.y >= this->_bounds.top && canFillAt(p, stopBit)) {}

    // Then fill by moving down
    while (++p.y < this->_bounds.bottom && canFillAt(p, stopBit))
        fillRow(p, pattern, stopBit);
}

template <class T>
void GraphicsMan_v2<T>::fill(Common::SeekableReadStream &pic) {
    byte pattern;

    if (!readByte(pic, pattern))
        return;

    while (true) {
        Common::Point p;

        if (!readPoint(pic, p))
            return;

        if (this->_bounds.contains(p))
            fillAt(p, pattern);
    }
}

template <class T>
void GraphicsMan_v2<T>::drawPic(Common::SeekableReadStream &pic, const Common::Point &pos) {
    // NOTE: The original engine only resets the color for overlays. As a result, room
    // pictures that draw without setting a color or clearing the screen, will use the
    // last color set by the previous picture. We assume this is unintentional and do
    // not copy this behavior.
    _color = 0;
    _offset = pos;

    while (true) {
        byte opcode = pic.readByte();

        if (pic.eos() || pic.err())
            error("Error reading picture");

        switch (opcode) {
        case 0xe0:
            drawCorners(pic, false);
            break;
        case 0xe1:
            drawCorners(pic, true);
            break;
        case 0xe2:
            drawRelativeLines(pic);
            break;
        case 0xe3:
            drawAbsoluteLines(pic);
            break;
        case 0xe4:
            fill(pic);
            break;
        case 0xe5:
            this->clearScreen();
            _color = 0x00;
            break;
        case 0xf0:
            _color = 0x00;
            break;
        case 0xf1:
            _color = 0x2a;
            break;
        case 0xf2:
            _color = 0x55;
            break;
        case 0xf3:
            _color = 0x7f;
            break;
        case 0xf4:
            _color = 0x80;
            break;
        case 0xf5:
            _color = 0xaa;
            break;
        case 0xf6:
            _color = 0xd5;
            break;
        case 0xf7:
            _color = 0xff;
            break;
        case 0xff:
            return;
        default:
            if (opcode >= 0xe0)
                error("Invalid pic opcode %02x", opcode);
            else
                warning("Expected pic opcode, but found data byte %02x", opcode);
        }
    }
}

template <class T>
void GraphicsMan_v3<T>::fillRowLeft(Common::Point p, const byte pattern, const bool stopBit) {
    byte color = this->getPatternColor(p, pattern);

    while (--p.x >= this->_bounds.left) {
        // In this version, when moving left, it no longer sets the palette first
        if (!this->_display.getPixelBit(p))
            return;
        if ((p.x % 7) == 6) {
            color = this->getPatternColor(p, pattern);
            this->_display.setPixelPalette(p, color);
        }
        this->_display.setPixelBit(p, color);
    }
}

template <class T>
void GraphicsMan_v3<T>::fillAt(Common::Point p, const byte pattern) {
    // If the row at p cannot be filled, we do nothing
    if (!this->canFillAt(p))
            return;

    this->fillRow(p, pattern);

    Common::Point q(p);

    // Fill up from p
    while (--q.y >= this->_bounds.top && this->canFillAt(q))
        this->fillRow(q, pattern);

    // Fill down from p
    while (++p.y < this->_bounds.bottom && this->canFillAt(p))
        this->fillRow(p, pattern);
}

} // End of namespace Adl

#endif