From 254e94f9120cb3b79b5d430d90a071ead285c7bf Mon Sep 17 00:00:00 2001
From: trotFunky <teo.couprie_diaz@telecom-sudparis.eu>
Date: Mon, 4 Nov 2019 14:30:28 +0100
Subject: [PATCH] Display list for the maze structure Objectives are not
 display-listed as they are removed when walked over.

---
 src/Maze.cpp | 71 ++++++++++++++++++++++++++++++++++------------------
 src/Maze.h   |  3 +++
 2 files changed, 50 insertions(+), 24 deletions(-)

diff --git a/src/Maze.cpp b/src/Maze.cpp
index 7d8f679..95346ea 100644
--- a/src/Maze.cpp
+++ b/src/Maze.cpp
@@ -42,10 +42,56 @@ Maze::Maze(const std::string& maze_map, unsigned int scaling_factor, const Textu
                                          static_cast<double>(y)};
             }
         }
+
+    preapre_display_list();
+}
+
+Maze::~Maze()
+{
+    if (display_list_index != -1)
+    {
+        glDeleteLists(display_list_index,1);
+    }
 }
 
 void Maze::draw()
 {
+    // Draw Maze
+    glCallList(display_list_index);
+
+    // Draw objectives
+    for (const Vec3d& objective_pos: objective_positions)
+    {
+        glPushMatrix();
+        glTranslatef((objective_pos.x+0.5)*scaling_factor,objective_pos.y,(objective_pos.z+0.5)*scaling_factor);
+        objective.draw_model();
+        glPopMatrix();
+    }
+}
+
+bool Maze::remove_objective(const Vec2i& position)
+{
+    Vec3d objective{static_cast<double>(position.x),
+                    objective_altitude,
+                    static_cast<double>(position.y)};
+
+    for (auto it = objective_positions.begin();it!=objective_positions.end();++it)
+    {
+        if (objective == *it)
+        {
+            objective_positions.erase(it);
+            return true;
+        }
+    }
+    return false;
+}
+
+void Maze::preapre_display_list()
+{
+    display_list_index = glGenLists(1);
+
+    glNewList(display_list_index,GL_COMPILE);
+
     // Draw ground
 
     glPolygonMode(GL_FRONT_AND_BACK,GL_FILL);
@@ -124,14 +170,6 @@ void Maze::draw()
     }
     glEnd();
 
-    for (const Vec3d& objective_pos: objective_positions)
-    {
-        glPushMatrix();
-        glTranslatef((objective_pos.x+0.5)*scaling_factor,objective_pos.y,(objective_pos.z+0.5)*scaling_factor);
-        objective.draw_model();
-        glPopMatrix();
-    }
-
     // Draw outside
 
     glBindTexture(GL_TEXTURE_2D,out.opengl_id[0]);
@@ -181,21 +219,6 @@ void Maze::draw()
     glVertex3f((outside_position.x+1)*scaling_factor,0,outside_position.z*scaling_factor);
 
     glEnd();
-}
 
-bool Maze::remove_objective(const Vec2i& position)
-{
-    Vec3d objective{static_cast<double>(position.x),
-                    objective_altitude,
-                    static_cast<double>(position.y)};
-
-    for (auto it = objective_positions.begin();it!=objective_positions.end();++it)
-    {
-        if (objective == *it)
-        {
-            objective_positions.erase(it);
-            return true;
-        }
-    }
-    return false;
+    glEndList();
 }
diff --git a/src/Maze.h b/src/Maze.h
index f434e72..69ad9f1 100644
--- a/src/Maze.h
+++ b/src/Maze.h
@@ -17,6 +17,7 @@ class Maze {
 public:
     Maze(const std::string& maze_map, unsigned int scaling_factor, const Texture& floor_texture,
          const Texture& wall_texture, const Texture& outside_texture, Model3D& objective);
+    ~Maze();
 
     void draw();
 
@@ -31,6 +32,8 @@ private:
     const Texture& out;
     Model3D& objective;
 
+    GLuint display_list_index = -1;
+
     const double objective_altitude = 0;
     const double wall_height = 2;
     unsigned corner_pos;