11 Canvas::Canvas(const QGLFormat& format, QWidget *parent)
12 : QGLWidget(format, parent), mesh(NULL),
13 scale(1), zoom(1), tilt(90), yaw(0), status(" ")
23 void Canvas::load_mesh(Mesh* m)
26 center = QVector3D(m->xmin() + m->xmax(),
27 m->ymin() + m->ymax(),
28 m->zmin() + m->zmax()) / 2;
30 pow(m->xmax() - m->xmin(), 2) +
31 pow(m->ymax() - m->ymin(), 2) +
32 pow(m->zmax() - m->zmin(), 2));
38 void Canvas::set_status(const QString &s)
44 void Canvas::clear_status()
50 void Canvas::initializeGL()
52 initializeGLFunctions();
54 mesh_shader.addShaderFromSourceFile(QGLShader::Vertex, ":/gl/mesh.vert");
55 mesh_shader.addShaderFromSourceFile(QGLShader::Fragment, ":/gl/mesh.frag");
58 backdrop = new Backdrop();
61 void Canvas::paintEvent(QPaintEvent *event)
65 glClearColor(0.0, 0.0, 0.0, 0.0);
66 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
67 glEnable(GL_DEPTH_TEST);
70 if (mesh) draw_mesh();
72 if (status.isNull()) return;
74 QPainter painter(this);
75 painter.setRenderHint(QPainter::Antialiasing);
76 painter.drawText(10, height() - 10, status);
80 void Canvas::draw_mesh()
84 // Load the transform and view matrices into the shader
86 mesh_shader.uniformLocation("transform_matrix"),
87 1, GL_FALSE, transform_matrix().data());
89 mesh_shader.uniformLocation("view_matrix"),
90 1, GL_FALSE, view_matrix().data());
92 // Compensate for z-flattening when zooming
93 glUniform1f(mesh_shader.uniformLocation("zoom"), 1/zoom);
95 // Find and enable the attribute location for vertex position
96 const GLuint vp = mesh_shader.attributeLocation("vertex_position");
97 glEnableVertexAttribArray(vp);
99 // Then draw the mesh with that vertex position
102 // Clean up state machine
103 glDisableVertexAttribArray(vp);
104 mesh_shader.release();
107 QMatrix4x4 Canvas::transform_matrix() const
110 m.rotate(tilt, QVector3D(1, 0, 0));
111 m.rotate(yaw, QVector3D(0, 0, 1));
113 m.translate(-center);
117 QMatrix4x4 Canvas::view_matrix() const
120 if (width() > height())
122 m.scale(-height() / float(width()), 1, 0.5);
126 m.scale(-1, width() / float(height()), 0.5);
128 m.scale(zoom, zoom, 1);
132 void Canvas::mousePressEvent(QMouseEvent* event)
134 if (event->button() == Qt::LeftButton ||
135 event->button() == Qt::RightButton)
137 mouse_pos = event->pos();
138 setCursor(Qt::ClosedHandCursor);
142 void Canvas::mouseReleaseEvent(QMouseEvent* event)
144 if (event->button() == Qt::LeftButton ||
145 event->button() == Qt::RightButton)
151 void Canvas::mouseMoveEvent(QMouseEvent* event)
153 auto p = event->pos();
154 auto d = p - mouse_pos;
156 if (event->buttons() & Qt::LeftButton)
158 yaw = fmod(yaw - d.x(), 360);
159 tilt = fmax(0, fmin(180, tilt - d.y()));
162 else if (event->buttons() & Qt::RightButton)
164 center = transform_matrix().inverted() *
165 view_matrix().inverted() *
166 QVector3D(-d.x() / (0.5*width()),
167 d.y() / (0.5*height()), 0);
173 void Canvas::wheelEvent(QWheelEvent *event)
175 // Find GL position before the zoom operation
176 // (to zoom about mouse cursor)
177 auto p = event->pos();
178 QVector3D v(1 - p.x() / (0.5*width()),
179 p.y() / (0.5*height()) - 1, 0);
180 QVector3D a = transform_matrix().inverted() *
181 view_matrix().inverted() * v;
183 if (event->delta() < 0)
185 for (int i=0; i > event->delta(); --i)
188 else if (event->delta() > 0)
190 for (int i=0; i < event->delta(); ++i)
194 // Then find the cursor's GL position post-zoom and adjust center.
195 QVector3D b = transform_matrix().inverted() *
196 view_matrix().inverted() * v;