+#include <QMouseEvent>
+#include <QDebug>
+
+#include <cmath>
+
+#include "canvas.h"
+#include "backdrop.h"
+#include "glmesh.h"
+#include "mesh.h"
+
+Canvas::Canvas(const QGLFormat& format, QWidget *parent)
+ : QGLWidget(format, parent), mesh(NULL),
+ scale(1), zoom(1), tilt(90), yaw(0), status(" ")
+{
+ // Nothing to do here
+}
+
+Canvas::~Canvas()
+{
+ delete mesh;
+}
+
+void Canvas::load_mesh(Mesh* m)
+{
+ mesh = new GLMesh(m);
+ center = QVector3D(m->xmin() + m->xmax(),
+ m->ymin() + m->ymax(),
+ m->zmin() + m->zmax()) / 2;
+ scale = 2 / sqrt(
+ pow(m->xmax() - m->xmin(), 2) +
+ pow(m->ymax() - m->ymin(), 2) +
+ pow(m->zmax() - m->zmin(), 2));
+
+ // Reset other camera parameters
+ zoom = 1;
+ yaw = 0;
+ tilt = 90;
+
+ update();
+
+ delete m;
+}
+
+void Canvas::set_status(const QString &s)
+{
+ status = s;
+ update();
+}
+
+void Canvas::clear_status()
+{
+ status = "";
+ update();
+}
+
+void Canvas::initializeGL()
+{
+ initializeGLFunctions();
+
+ mesh_shader.addShaderFromSourceFile(QGLShader::Vertex, ":/gl/mesh.vert");
+ mesh_shader.addShaderFromSourceFile(QGLShader::Fragment, ":/gl/mesh.frag");
+ mesh_shader.link();
+
+ backdrop = new Backdrop();
+}
+
+void Canvas::paintEvent(QPaintEvent *event)
+{
+ Q_UNUSED(event);
+
+ glClearColor(0.0, 0.0, 0.0, 0.0);
+ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+ glEnable(GL_DEPTH_TEST);
+
+ backdrop->draw();
+ if (mesh) draw_mesh();
+
+ if (status.isNull()) return;
+
+ QPainter painter(this);
+ painter.setRenderHint(QPainter::Antialiasing);
+ painter.drawText(10, height() - 10, status);
+}
+
+
+void Canvas::draw_mesh()
+{
+ mesh_shader.bind();
+
+ // Load the transform and view matrices into the shader
+ glUniformMatrix4fv(
+ mesh_shader.uniformLocation("transform_matrix"),
+ 1, GL_FALSE, transform_matrix().data());
+ glUniformMatrix4fv(
+ mesh_shader.uniformLocation("view_matrix"),
+ 1, GL_FALSE, view_matrix().data());
+
+ // Compensate for z-flattening when zooming
+ glUniform1f(mesh_shader.uniformLocation("zoom"), 1/zoom);
+
+ // Find and enable the attribute location for vertex position
+ const GLuint vp = mesh_shader.attributeLocation("vertex_position");
+ glEnableVertexAttribArray(vp);
+
+ // Then draw the mesh with that vertex position
+ mesh->draw(vp);
+
+ // Clean up state machine
+ glDisableVertexAttribArray(vp);
+ mesh_shader.release();
+}
+
+QMatrix4x4 Canvas::transform_matrix() const
+{
+ QMatrix4x4 m;
+ m.rotate(tilt, QVector3D(1, 0, 0));
+ m.rotate(yaw, QVector3D(0, 0, 1));
+ m.scale(scale);
+ m.translate(-center);
+ return m;
+}
+
+QMatrix4x4 Canvas::view_matrix() const
+{
+ QMatrix4x4 m;
+ if (width() > height())
+ {
+ m.scale(-height() / float(width()), 1, 0.5);
+ }
+ else
+ {
+ m.scale(-1, width() / float(height()), 0.5);
+ }
+ m.scale(zoom, zoom, 1);
+ return m;
+}
+
+void Canvas::mousePressEvent(QMouseEvent* event)
+{
+ if (event->button() == Qt::LeftButton ||
+ event->button() == Qt::RightButton)
+ {
+ mouse_pos = event->pos();
+ setCursor(Qt::ClosedHandCursor);
+ }
+}
+
+void Canvas::mouseReleaseEvent(QMouseEvent* event)
+{
+ if (event->button() == Qt::LeftButton ||
+ event->button() == Qt::RightButton)
+ {
+ unsetCursor();
+ }
+}
+
+void Canvas::mouseMoveEvent(QMouseEvent* event)
+{
+ auto p = event->pos();
+ auto d = p - mouse_pos;
+
+ if (event->buttons() & Qt::LeftButton)
+ {
+ yaw = fmod(yaw - d.x(), 360);
+ tilt = fmax(0, fmin(180, tilt - d.y()));
+ update();
+ }
+ else if (event->buttons() & Qt::RightButton)
+ {
+ center = transform_matrix().inverted() *
+ view_matrix().inverted() *
+ QVector3D(-d.x() / (0.5*width()),
+ d.y() / (0.5*height()), 0);
+ update();
+ }
+ mouse_pos = p;
+}
+
+void Canvas::wheelEvent(QWheelEvent *event)
+{
+ // Find GL position before the zoom operation
+ // (to zoom about mouse cursor)
+ auto p = event->pos();
+ QVector3D v(1 - p.x() / (0.5*width()),
+ p.y() / (0.5*height()) - 1, 0);
+ QVector3D a = transform_matrix().inverted() *
+ view_matrix().inverted() * v;
+
+ if (event->delta() < 0)
+ {
+ for (int i=0; i > event->delta(); --i)
+ zoom *= 1.001;
+ }
+ else if (event->delta() > 0)
+ {
+ for (int i=0; i < event->delta(); ++i)
+ zoom /= 1.001;
+ }
+
+ // Then find the cursor's GL position post-zoom and adjust center.
+ QVector3D b = transform_matrix().inverted() *
+ view_matrix().inverted() * v;
+ center += b - a;
+ update();
+}
projects / fstl / commitdiff