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Diffstat (limited to 'demos/embedded/raycasting/raycasting.cpp')
| -rw-r--r-- | demos/embedded/raycasting/raycasting.cpp | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/demos/embedded/raycasting/raycasting.cpp b/demos/embedded/raycasting/raycasting.cpp new file mode 100644 index 0000000..7d61c4f --- /dev/null +++ b/demos/embedded/raycasting/raycasting.cpp @@ -0,0 +1,310 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the demonstration applications of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at http://qt.nokia.com/contact. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include <QtCore> +#include <QtGui> + +#include <math.h> + +#ifndef M_PI +#define M_PI 3.14159265358979323846 +#endif + +#define WORLD_SIZE 8 +int world_map[WORLD_SIZE][WORLD_SIZE] = { + { 1, 1, 1, 1, 6, 1, 1, 1 }, + { 1, 0, 0, 1, 0, 0, 0, 7 }, + { 1, 1, 0, 1, 0, 1, 1, 1 }, + { 6, 0, 0, 0, 0, 0, 0, 3 }, + { 1, 8, 8, 0, 8, 0, 8, 1 }, + { 2, 2, 0, 0, 8, 8, 7, 1 }, + { 3, 0, 0, 0, 0, 0, 0, 5 }, + { 2, 2, 2, 2, 7, 4, 4, 4 }, +}; + +#define TEXTURE_SIZE 64 +#define TEXTURE_BLOCK (TEXTURE_SIZE * TEXTURE_SIZE) + +class Raycasting: public QWidget +{ +public: + Raycasting(QWidget *parent = 0) + : QWidget(parent) + , angle(0.5) + , playerPos(1.5, 1.5) + , angleDelta(0) + , moveDelta(0) { + + // http://www.areyep.com/RIPandMCS-TextureLibrary.html + textureImg.load(":/textures.png"); + textureImg = textureImg.convertToFormat(QImage::Format_ARGB32); + Q_ASSERT(textureImg.width() == TEXTURE_SIZE * 2); + Q_ASSERT(textureImg.bytesPerLine() == 4 * TEXTURE_SIZE * 2); + textureCount = textureImg.height() / TEXTURE_SIZE; + + watch.start(); + ticker.start(25, this); + setAttribute(Qt::WA_OpaquePaintEvent, true); + } + + void updatePlayer() { + int interval = qBound(20, watch.elapsed(), 250); + watch.start(); + angle += angleDelta * interval / 1000; + qreal step = moveDelta * interval / 1000; + qreal dx = cos(angle) * step; + qreal dy = sin(angle) * step; + QPointF pos = playerPos + 3 * QPointF(dx, dy); + int xi = static_cast<int>(pos.x()); + int yi = static_cast<int>(pos.y()); + if (world_map[yi][xi] == 0) + playerPos = playerPos + QPointF(dx, dy); + } + + void showFps() { + static QTime frameTick; + static int totalFrame = 0; + if (!(totalFrame & 31)) { + int elapsed = frameTick.elapsed(); + frameTick.start(); + int fps = 32 * 1000 / (1 + elapsed); + setWindowTitle(QString("Raycasting (%1 FPS)").arg(fps)); + } + totalFrame++; + } + + void render() { + + // setup the screen surface + if (buffer.size() != size()) + buffer = QImage(size(), QImage::Format_ARGB32); + int bufw = buffer.width(); + int bufh = buffer.height(); + + // we intentionally cheat here, to avoid detach + const uchar *ptr = buffer.bits(); + QRgb *start = (QRgb*)(ptr); + QRgb stride = buffer.bytesPerLine() / 4; + QRgb *finish = start + stride * bufh; + + // prepare the texture pointer + const uchar *src = textureImg.bits(); + const QRgb *texsrc = reinterpret_cast<const QRgb*>(src); + + // cast all rays here + qreal sina = sin(angle); + qreal cosa = cos(angle); + qreal u = cosa - sina; + qreal v = sina + cosa; + qreal du = 2 * sina / bufw; + qreal dv = -2 * cosa / bufw; + + for (int ray = 0; ray < bufw; ++ray, u += du, v += dv) { + // everytime this ray advances 'u' units in x direction, + // it also advanced 'v' units in y direction + qreal uu = (u < 0) ? -u : u; + qreal vv = (v < 0) ? -v : v; + qreal duu = 1 / uu; + qreal dvv = 1 / vv; + int stepx = (u < 0) ? -1 : 1; + int stepy = (v < 0) ? -1 : 1; + + // the cell in the map that we need to check + qreal px = playerPos.x(); + qreal py = playerPos.y(); + int mapx = static_cast<int>(px); + int mapy = static_cast<int>(py); + + // the position and texture for the hit + int texture = 0; + qreal hitdist = 0.1; + qreal texofs = 0; + bool dark = false; + + // first hit at constant x and constant y lines + qreal distx = (u > 0) ? (mapx + 1 - px) * duu : (px - mapx) * duu; + qreal disty = (v > 0) ? (mapy + 1 - py) * dvv : (py - mapy) * dvv; + + // loop until we hit something + while (texture <= 0) { + if (distx > disty) { + // shorter distance to a hit in constant y line + hitdist = disty; + disty += dvv; + mapy += stepy; + texture = world_map[mapy][mapx]; + if (texture > 0) { + dark = true; + if (stepy > 0) { + qreal ofs = px + u * (mapy - py) / v; + texofs = ofs - floor(ofs); + } else { + qreal ofs = px + u * (mapy + 1 - py) / v; + texofs = ofs - floor(ofs); + } + } + } else { + // shorter distance to a hit in constant x line + hitdist = distx; + distx += duu; + mapx += stepx; + texture = world_map[mapy][mapx]; + if (texture > 0) { + if (stepx > 0) { + qreal ofs = py + v * (mapx - px) / u; + texofs = ofs - floor(ofs); + } else { + qreal ofs = py + v * (mapx + 1 - px) / u; + texofs = ceil(ofs) - ofs; + } + } + } + } + + // get the texture, note that the texture image + // has two textures horizontally, "normal" vs "dark" + int col = static_cast<int>(texofs * TEXTURE_SIZE); + col = qBound(0, col, TEXTURE_SIZE - 1); + texture = (texture - 1) % textureCount; + const QRgb *tex = texsrc + TEXTURE_BLOCK * texture * 2 + + (TEXTURE_SIZE * 2 * col); + if (dark) + tex += TEXTURE_SIZE; + + // start from the texture center (horizontally) + int h = static_cast<int>(bufw / hitdist / 2); + int dy = (TEXTURE_SIZE << 12) / h; + int p1 = ((TEXTURE_SIZE / 2) << 12) - dy; + int p2 = p1 + dy; + + // start from the screen center (vertically) + // y1 will go up (decrease), y2 will go down (increase) + int y1 = bufh / 2; + int y2 = y1 + 1; + QRgb *pixel1 = start + y1 * stride + ray; + QRgb *pixel2 = pixel1 + stride; + + // map the texture to the sliver + while (y1 >= 0 && y2 < bufh && p1 >= 0) { + *pixel1 = tex[p1 >> 12]; + *pixel2 = tex[p2 >> 12]; + p1 -= dy; + p2 += dy; + --y1; + ++y2; + pixel1 -= stride; + pixel2 += stride; + } + + // ceiling and floor + for (; pixel1 > start; pixel1 -= stride) + *pixel1 = qRgb(0, 0, 0); + for (; pixel2 < finish; pixel2 += stride) + *pixel2 = qRgb(96, 96, 96); + } + + update(); + } + +protected: + + void timerEvent(QTimerEvent*) { + updatePlayer(); + render(); + showFps(); + } + + void paintEvent(QPaintEvent *event) { + QPainter p(this); + p.drawImage(event->rect(), buffer, event->rect()); + } + + void keyPressEvent(QKeyEvent *event) { + event->accept(); + if (event->key() == Qt::Key_Left) + angleDelta = 1.3 * M_PI; + if (event->key() == Qt::Key_Right) + angleDelta = -1.3 * M_PI; + if (event->key() == Qt::Key_Up) + moveDelta = 2.5; + if (event->key() == Qt::Key_Down) + moveDelta = -2.5; + } + + void keyReleaseEvent(QKeyEvent *event) { + event->accept(); + if (event->key() == Qt::Key_Left) + angleDelta = (angleDelta > 0) ? 0 : angleDelta; + if (event->key() == Qt::Key_Right) + angleDelta = (angleDelta < 0) ? 0 : angleDelta; + if (event->key() == Qt::Key_Up) + moveDelta = (moveDelta > 0) ? 0 : moveDelta; + if (event->key() == Qt::Key_Down) + moveDelta = (moveDelta < 0) ? 0 : moveDelta; + } + +private: + QTime watch; + QBasicTimer ticker; + QImage buffer; + qreal angle; + QPointF playerPos; + qreal angleDelta; + qreal moveDelta; + QImage textureImg; + int textureCount; +}; + +int main(int argc, char **argv) +{ + QApplication app(argc, argv); + + Raycasting w; + w.setWindowTitle("Raycasting"); +#if defined(Q_OS_SYMBIAN) + w.showMaximized(); +#else + w.resize(640, 480); + w.show(); +#endif + + return app.exec(); +} |