Add simple Matrix4x4 class for more generic transformations.

4 files changed, 202 insertions, 22 deletions

diff --git a/matrix4x4.cpp b/matrix4x4.cpp
new file mode 100644
index 0000000..66ecb81
--- /dev/null
+++ b/matrix4x4.cpp
@@ -0,0 +1,141 @@
+#include "matrix4x4.h"
+
+Matrix4x4::Matrix4x4()
+{
+    qreal identity[] =
+    {
+        1, 0, 0, 0,
+        0, 1, 0, 0,
+        0, 0, 1, 0,
+        0, 0, 0, 1
+    };
+
+    setData(identity);
+}
+
+Matrix4x4::Matrix4x4(qreal *data)
+{
+    setData(data);
+}
+
+void Matrix4x4::setData(qreal *data)
+{
+    for (int i = 0; i < 16; ++i)
+        m[i] = data[i];
+}
+
+Matrix4x4 &Matrix4x4::operator*=(const Matrix4x4 &rhs)
+{
+    const Matrix4x4 lhs = *this;
+    for (int i = 0; i < 4; ++i) {
+        for (int j = 0; j < 4; ++j) {
+            m[4*i + j] = 0;
+            for (int k = 0; k < 4; ++k)
+                m[4*i + j] += lhs.m[4*i + k] * rhs.m[4*k + j];
+        }
+    }
+    return *this;
+}
+
+Matrix4x4 Matrix4x4::operator*(const Matrix4x4 &other) const
+{
+    return Matrix4x4(*this) *= other;
+}
+
+Matrix4x4 Matrix4x4::fromRotation(qreal angle, Qt::Axis axis)
+{
+    QTransform rot;
+    rot.rotate(angle);
+    switch (axis) {
+    case Qt::XAxis:
+        {
+        qreal data[] =
+        {
+            1, 0, 0, 0,
+            0, rot.m11(), rot.m12(), 0,
+            0, rot.m21(), rot.m22(), 0,
+            0, 0, 0, 1
+        };
+        return Matrix4x4(data);
+        }
+    case Qt::YAxis:
+        {
+        qreal data[] =
+        {
+            rot.m11(), 0, rot.m12(), 0,
+            0, 1, 0, 0,
+            rot.m21(), 0, rot.m22(), 0,
+            0, 0, 0, 1
+        };
+        return Matrix4x4(data);
+        }
+    case Qt::ZAxis:
+        {
+        qreal data[] =
+        {
+            rot.m11(), rot.m12(), 0, 0,
+            rot.m21(), rot.m22(), 0, 0,
+            0, 0, 1, 0,
+            0, 0, 0, 1
+        };
+        return Matrix4x4(data);
+        }
+    default:
+        return Matrix4x4();
+    }
+}
+
+Matrix4x4 Matrix4x4::fromTranslation(qreal dx, qreal dy, qreal dz)
+{
+    qreal data[] =
+    {
+        1, 0, 0, 0,
+        0, 1, 0, 0,
+        0, 0, 1, 0,
+        dx, dy, dz, 1
+    };
+    return Matrix4x4(data);
+}
+
+Matrix4x4 Matrix4x4::fromScale(qreal sx, qreal sy, qreal sz)
+{
+    qreal data[] =
+    {
+        sx, 0, 0, 0,
+        0, sy, 0, 0,
+        0, 0, sz, 0,
+        0, 0, 0, 1
+    };
+    return Matrix4x4(data);
+}
+
+Matrix4x4 Matrix4x4::fromProjection(qreal fov)
+{
+    qreal data[] =
+    {
+        1, 0, 0, 0,
+        0, 1, 0, 0,
+        0, 0, 1, fov,
+        0, 0, 0, 0
+    };
+    return Matrix4x4(data);
+}
+
+Matrix4x4 convert2dTo3d()
+{
+    qreal data[] =
+    {
+        1, 0, 0, 0,
+        0, 1, 0, 0,
+        0, 0, 0, 0,
+        0, 0, 0, 1
+    };
+    return Matrix4x4(data);
+}
+
+QTransform Matrix4x4::toQTransform() const
+{
+    return QTransform(m[0], m[1], m[3],
+                      m[4], m[5], m[7],
+                      m[12], m[13], m[15]);
+}
diff --git a/matrix4x4.h b/matrix4x4.h
new file mode 100644
index 0000000..588bb40
--- /dev/null
+++ b/matrix4x4.h
@@ -0,0 +1,30 @@
+#ifndef MATRIX4X4_H
+#define MATRIX4X4_H
+
+#include <qnamespace.h>
+#include <QTransform>
+
+class Matrix4x4
+{
+public:
+    Matrix4x4();
+    Matrix4x4(qreal *data);
+
+    Matrix4x4 &operator*=(const Matrix4x4 &other);
+    Matrix4x4 operator*(const Matrix4x4 &other) const;
+
+    static Matrix4x4 fromRotation(qreal angle, Qt::Axis axis);
+    static Matrix4x4 fromTranslation(qreal dx, qreal dy, qreal dz);
+    static Matrix4x4 fromScale(qreal sx, qreal sy, qreal sz);
+    static Matrix4x4 fromProjection(qreal fov);
+    static Matrix4x4 convert2dTo3d();
+
+    QTransform toQTransform() const;
+
+    void setData(qreal *data);
+
+private:
+    qreal m[16];
+};
+
+#endif
diff --git a/mazescene.cpp b/mazescene.cpp
index 26fce9d..9b6e1ac 100644
--- a/mazescene.cpp
+++ b/mazescene.cpp
@@ -14,6 +14,8 @@
 #include <qmath.h>
 #include <qdebug.h>
 
+#include "matrix4x4.h"
+
 #ifdef USE_PHONON
 #include "mediaplayer/mediaplayer.h"
 #endif
@@ -162,9 +164,6 @@ void MazeScene::drawBackground(QPainter *painter, const QRectF &rect)
     painter->fillRect(QRectF(rect.topLeft(), QPointF(rect.right(), rect.center().y())), QColor(100, 120, 200));
     painter->fillRect(QRectF(QPointF(rect.left(), rect.center().y()), rect.bottomRight()), QColor(127, 190, 100));
 
-    QTransform rotation = rotatingTransform(m_cameraAngle);
-    rotation.translate(-m_cameraPos.x(), -m_cameraPos.y());
-
     static QImage floor = QImage("floor.png").convertToFormat(QImage::Format_RGB32);
     QBrush floorBrush(floor);
 
@@ -176,21 +175,29 @@ void MazeScene::drawBackground(QPainter *painter, const QRectF &rect)
     floorBrush.setTransform(brushScale);
     ceilingBrush.setTransform(brushScale);
 
-    QTransform project;
-    const qreal fov = 0.5;
-    const qreal wallHeight = 0.5 + 0.04 * qSin(0.01 * m_walkTime) + 0.1;
-    const qreal ceilingHeight = -0.5 + 0.04 * qSin(0.01 * m_walkTime) + 0.1;
     const QRectF r(1, 1, m_width-2, m_height-2);
 
+    Matrix4x4 m;
+    m *= Matrix4x4::fromRotation(m_cameraAngle, Qt::YAxis);
+    m *= Matrix4x4::fromProjection(0.5);
+
+    qreal heightOffset = 0.04 * qSin(0.01 * m_walkTime) + 0.1;
+
+    Matrix4x4 floorMatrix = Matrix4x4::fromRotation(90, Qt::XAxis);
+    floorMatrix *= Matrix4x4::fromTranslation(-m_cameraPos.x(), heightOffset + 0.5, -m_cameraPos.y());
+    floorMatrix *= m;
+
     painter->save();
-    project = QTransform(rotation.m11(), 0, fov * rotation.m12(), rotation.m21(), 0, fov * rotation.m22(), rotation.m31(), wallHeight, fov * rotation.m32());
-    painter->setTransform(project, true);
+    painter->setTransform(floorMatrix.toQTransform(), true);
     painter->fillRect(r, floorBrush);
     painter->restore();
 
+    Matrix4x4 ceilingMatrix = Matrix4x4::fromRotation(90, Qt::XAxis);
+    ceilingMatrix *= Matrix4x4::fromTranslation(-m_cameraPos.x(), heightOffset - 0.5, -m_cameraPos.y());
+    ceilingMatrix *= m;
+
     painter->save();
-    project = QTransform(rotation.m11(), 0, fov * rotation.m12(), rotation.m21(), 0, fov * rotation.m22(), rotation.m31(), ceilingHeight, fov * rotation.m32());
-    painter->setTransform(project, true);
+    painter->setTransform(ceilingMatrix.toQTransform(), true);
     painter->fillRect(r, ceilingBrush);
     painter->restore();
 
@@ -423,29 +430,31 @@ void ProjectedItem::setImage(const QImage &image)
 
 void ProjectedItem::updateTransform(const QPointF &cameraPos, qreal cameraAngle, qreal time)
 {
-    QTransform rotation = rotatingTransform(cameraAngle);
-    rotation.translate(-cameraPos.x(), -cameraPos.y());
+    QTransform rotation;
+    rotation *= QTransform().translate(-cameraPos.x(), -cameraPos.y());
+    rotation *= rotatingTransform(cameraAngle);
 
     QPointF ca = rotation.map(m_a);
     QPointF cb = rotation.map(m_b);
+    qreal zm = QLineF(QPointF(), (ca + cb) / 2).length();
 
     if (ca.y() <= 0 && cb.y() <= 0) {
         setVisible(false);
         return;
     }
 
-    const qreal mx = ca.x() - cb.x();
-    const qreal tx = 0.5 * (ca.x() + cb.x());
-    const qreal mz = ca.y() - cb.y();
-    const qreal tz = 0.5 * (ca.y() + cb.y());
     const qreal fov = 0.5;
+    QPointF center = (m_a + m_b) / 2;
 
-    const QTransform project(mx, 0, mz * fov, 0, 1, 0, tx, 0.04 * qSin(10 * time) + 0.1, tz * fov);
-    const qreal zm = QLineF(QPointF(), (ca + cb) / 2).length();
+    Matrix4x4 m;
+    m *= Matrix4x4::fromRotation(-QLineF(m_b, m_a).angle(), Qt::YAxis);
+    m *= Matrix4x4::fromTranslation(center.x() - cameraPos.x(), 0.04 * qSin(10 * time) + 0.1, center.y() - cameraPos.y());
+    m *= Matrix4x4::fromRotation(cameraAngle, Qt::YAxis);
+    m *= Matrix4x4::fromProjection(fov);
 
     setVisible(true);
     setZValue(-zm);
-    setTransform(project);
+    setTransform(m.toQTransform());
 }
 
 void MazeScene::keyPressEvent(QKeyEvent *event)
diff --git a/qt3d.pro b/qt3d.pro
index 7f408c1..974978d 100644
--- a/qt3d.pro
+++ b/qt3d.pro
@@ -29,5 +29,5 @@ DEPLOYMENT_PLUGIN += phonon_ds9 phonon_waveout
 }
 
 # Input
-HEADERS += mazescene.h
-SOURCES += main.cpp mazescene.cpp
+HEADERS += mazescene.h matrix4x4.h
+SOURCES += main.cpp mazescene.cpp matrix4x4.cpp