From 5c19700e42bd7b639c83f92f6c31aef38ed84373 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Th=C3=A9ophile=20Bastian?= <contact@tobast.fr>
Date: Sat, 27 Jan 2018 18:33:50 +0100
Subject: [PATCH] =?UTF-8?q?Create=20a=20basic=20glut=20renderer=20?=
 =?UTF-8?q?=E2=80=94=20yet=20untested?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 common_structures.hpp | 16 ++++++++++
 render/GlutRender.cpp | 71 +++++++++++++++++++++++++++++++++++++++++++
 render/GlutRender.hpp | 31 +++++++++++++++++++
 3 files changed, 118 insertions(+)
 create mode 100644 render/GlutRender.cpp
 create mode 100644 render/GlutRender.hpp

diff --git a/common_structures.hpp b/common_structures.hpp
index 3993966..b38e2d6 100644
--- a/common_structures.hpp
+++ b/common_structures.hpp
@@ -3,10 +3,22 @@
  **/
 
 #include <functional>  // Hash
+#include <vector>
+#include <cassert>
 
 struct Point {
     Point(double x, double y, double z) : x(x), y(y), z(z) {}
     double x, y, z;
+
+    double operator[](unsigned i) const {
+        assert(0 <= i && i < 3);
+        switch(i) {
+            case 0:     return x;
+            case 1:     return y;
+            case 2:     return z;
+            default:    return 0;
+        }
+    }
 };
 
 struct Face {
@@ -19,6 +31,10 @@ struct Face {
     int operator[](unsigned i) const {
         return vert[i % 3]; // dodge errors
     }
+    const Point& pt(int id, const std::vector<Point>& pts) const {
+        assert(0 <= id && id < 3);
+        return pts[vert[id]];
+    }
 };
 
 namespace std {
diff --git a/render/GlutRender.cpp b/render/GlutRender.cpp
new file mode 100644
index 0000000..b9632ab
--- /dev/null
+++ b/render/GlutRender.cpp
@@ -0,0 +1,71 @@
+#include "GlutRender.hpp"
+
+#include <GL/gl.h>
+#include <GL/glut.h>
+#include <cstring>
+
+GlutRender& GlutRender::get_instance() {
+    static GlutRender instance;
+    return instance;
+}
+
+GlutRender::GlutRender() { }
+
+void GlutRender::init(int* argc, char** argv,
+        int wid, int hei, const char* win_name)
+{
+   glutInit(argc, argv);
+   glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
+   glutInitWindowSize(wid, hei);
+   glutCreateWindow(win_name);
+
+   glClearColor(0.0, 0.0, 0.0, 0.0);
+   glShadeModel(GL_FLAT);
+
+   glutDisplayFunc(display_handle);
+   glutReshapeFunc(reshape_handle);
+}
+
+void GlutRender::cleanup() {
+}
+
+void GlutRender::add_mesh(const Mesh* mesh) {
+    meshes.insert(mesh);
+}
+
+void GlutRender::remove_mesh(const Mesh* mesh) {
+    meshes.erase(mesh);
+}
+
+void GlutRender::run() {
+}
+
+void GlutRender::reshape(int wid, int hei) {
+   glViewport(0, 0, (GLsizei) wid, (GLsizei) hei);
+   glMatrixMode(GL_PROJECTION);
+   glLoadIdentity();
+   gluOrtho2D(0.0, (GLdouble) wid, 0.0, (GLdouble) hei);
+}
+
+void GlutRender::display() {
+    for(const Mesh* mesh: meshes) {
+        const std::vector<Point>& points = mesh->get_vertices();
+        for(const Face& face: mesh->get_faces()) {
+            const Point& p0 = face.pt(0, points),
+                         p1 = face.pt(2, points),
+                         p2 = face.pt(2, points);
+            glBegin(GL_TRIANGLES);
+                glVertex3d(p0[0], p0[1], p0[2]);
+                glVertex3d(p1[0], p1[1], p1[2]);
+                glVertex3d(p2[0], p2[1], p2[2]);
+            glEnd();
+        }
+    }
+}
+
+void GlutRender::reshape_handle(int wid, int hei) {
+    get_instance().reshape(wid, hei);
+}
+void GlutRender::display_handle() {
+    get_instance().display();
+}
diff --git a/render/GlutRender.hpp b/render/GlutRender.hpp
new file mode 100644
index 0000000..699a26a
--- /dev/null
+++ b/render/GlutRender.hpp
@@ -0,0 +1,31 @@
+/** The most basic renderer — a stupid glut application */
+
+#include "../Mesh.hpp"
+#include <set>
+
+class GlutRender {
+    public:
+        static GlutRender& get_instance();
+
+        GlutRender(GlutRender const&) = delete;
+        void operator=(GlutRender const&) = delete;
+
+        void init(int* argc, char** argv,
+                int wid, int hei, const char* win_name);
+        void cleanup();
+        void add_mesh(const Mesh* mesh);
+        void remove_mesh(const Mesh* mesh);
+        void run();
+
+    private: //meth
+        GlutRender();
+
+    protected:
+        void reshape(int wid, int hei);
+        void display();
+
+        static void reshape_handle(int wid, int hei);
+        static void display_handle();
+    private:
+        std::set<const Mesh*> meshes;
+};