Dump of hello world ifc viewer code

src/ifcviewer/ViewportWindow.h

@@ -0,0 +1,146 @@
+/********************************************************************************
+ *                                                                              *
+ * This file is part of IfcOpenShell.                                           *
+ *                                                                              *
+ * IfcOpenShell is free software: you can redistribute it and/or modify         *
+ * it under the terms of the Lesser GNU General Public License as published by  *
+ * the Free Software Foundation, either version 3.0 of the License, or          *
+ * (at your option) any later version.                                          *
+ *                                                                              *
+ * IfcOpenShell 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                 *
+ * Lesser GNU General Public License for more details.                          *
+ *                                                                              *
+ * You should have received a copy of the Lesser GNU General Public License     *
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.         *
+ *                                                                              *
+ ********************************************************************************/
+
+#ifndef VIEWPORTWINDOW_H
+#define VIEWPORTWINDOW_H
+
+#include <QWindow>
+#include <QOpenGLContext>
+#include <QtOpenGL/QOpenGLFunctions_4_5_Core>
+#include <QTimer>
+#include <QElapsedTimer>
+#include <QMatrix4x4>
+#include <QVector3D>
+
+#include <vector>
+#include <cstdint>
+#include <mutex>
+
+struct MaterialInfo {
+    float r = 0.75f, g = 0.75f, b = 0.78f, a = 1.0f;
+};
+
+struct UploadChunk {
+    // Interleaved per-vertex layout (8 floats / 32 bytes per vertex):
+    //   pos(3 float) + normal(3 float) + object_id(1 float bitcast from uint)
+    //   + color(1 float holding RGBA8 packed bytes, read on the GPU as
+    //   GL_UNSIGNED_BYTE * 4 normalized).
+    std::vector<float> vertices;
+    std::vector<uint32_t> indices; // local to this chunk's vertices
+    uint32_t object_id = 0;
+};
+
+class ViewportWindow : public QWindow {
+    Q_OBJECT
+public:
+    explicit ViewportWindow(QWindow* parent = nullptr);
+    ~ViewportWindow();
+
+    void uploadChunk(const UploadChunk& chunk);
+    void resetScene();
+
+    void setSelectedObjectId(uint32_t id);
+    uint32_t pickObjectAt(int x, int y);
+
+signals:
+    void objectPicked(uint32_t object_id);
+    void initialized();
+
+protected:
+    void exposeEvent(QExposeEvent* event) override;
+    void resizeEvent(QResizeEvent* event) override;
+    bool event(QEvent* event) override;
+
+private:
+    void initGL();
+    void render();
+    void renderPickPass();
+    void renderAxisGizmo();
+    void updateCamera();
+    void buildShaders();
+    void buildAxisGizmo();
+    bool growVbo(size_t needed_total);
+    bool growEbo(size_t needed_total);
+
+    // Mouse interaction
+    void handleMousePress(QMouseEvent* event);
+    void handleMouseRelease(QMouseEvent* event);
+    void handleMouseMove(QMouseEvent* event);
+    void handleWheel(QWheelEvent* event);
+
+    QOpenGLContext* context_ = nullptr;
+    QOpenGLFunctions_4_5_Core* gl_ = nullptr;
+    QTimer render_timer_;
+    QElapsedTimer frame_clock_;
+    bool gl_initialized_ = false;
+
+    // Shaders
+    GLuint main_program_ = 0;
+    GLuint pick_program_ = 0;
+    GLuint axis_program_ = 0;
+
+    // Axis gizmo (separate VAO/VBO since vertex layout differs from scene)
+    GLuint axis_vao_ = 0;
+    GLuint axis_vbo_ = 0;
+
+    // Geometry buffers - one big buffer pair
+    GLuint vao_ = 0;
+    GLuint vbo_ = 0;
+    GLuint ebo_ = 0;
+    size_t vbo_capacity_ = 0;
+    size_t ebo_capacity_ = 0;
+    size_t vbo_used_ = 0;  // in bytes
+    size_t ebo_used_ = 0;  // in bytes
+    uint32_t vertex_count_ = 0;
+
+    // Pick framebuffer
+    GLuint pick_fbo_ = 0;
+    GLuint pick_color_tex_ = 0;
+    GLuint pick_depth_rbo_ = 0;
+    int pick_width_ = 0;
+    int pick_height_ = 0;
+
+    // The entire scene is a single mega-batch: per-vertex color removes the
+    // need to switch materials between draw calls. Indices are written into
+    // the EBO already offset by base_vertex so one glDrawElements covers all.
+    uint32_t total_index_count_ = 0;
+    std::mutex upload_mutex_;
+
+    // Camera
+    QVector3D camera_target_{0, 0, 0};
+    float camera_distance_ = 50.0f;
+    float camera_yaw_ = 45.0f;
+    float camera_pitch_ = 30.0f;
+    QMatrix4x4 view_matrix_;
+    QMatrix4x4 proj_matrix_;
+
+    // Mouse state
+    Qt::MouseButton active_button_ = Qt::NoButton;
+    QPoint last_mouse_pos_;
+
+    // Selection
+    uint32_t selected_object_id_ = 0;
+    bool pick_requested_ = false;
+    int pick_x_ = 0, pick_y_ = 0;
+
+    // Stats
+    uint32_t total_triangles_ = 0;
+};
+
+#endif // VIEWPORTWINDOW_H