From 24d21d77cba25e31e7324c2e493acd3af9c74fb8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Th=C3=A9ophile=20Bastian?= <contact@tobast.fr>
Date: Wed, 14 Feb 2018 17:22:27 +0100
Subject: [PATCH] Use rendering at startup only for perlin ground

---
 main_bounce.cpp       |  2 +-
 render/GlutRender.cpp | 34 +++++++++++++++++++++++++---------
 render/GlutRender.hpp | 27 +++++++++++++++++++++------
 3 files changed, 47 insertions(+), 16 deletions(-)

diff --git a/main_bounce.cpp b/main_bounce.cpp
index 58d022b..bbef7f3 100644
--- a/main_bounce.cpp
+++ b/main_bounce.cpp
@@ -50,7 +50,7 @@ int main(int argc, char** argv) {
 
     if(perlin) {
         perlin_ground.get_surface()->set_color(Color(0.13, 0.82, 0.21));
-        render.add_surface(perlin_ground.get_surface(), bbox_2, 1.2);
+        render.add_surface(perlin_ground.get_surface(), bbox_2, false, 0.50);
     }
     else {
         ground_mesh.get_mesh()->set_color(Color(0.13, 0.82, 0.21));
diff --git a/render/GlutRender.cpp b/render/GlutRender.cpp
index c00cc57..3a0c50d 100644
--- a/render/GlutRender.cpp
+++ b/render/GlutRender.cpp
@@ -12,6 +12,13 @@ GlutRender& GlutRender::get_instance() {
     return instance;
 }
 
+Mesh GlutRender::SurfaceDetails::render() const {
+    return MarchingCubes(*surface, box,
+            resolution)
+        .add_hint(surface->location_hint())
+        ();
+}
+
 GlutRender::GlutRender()
     : followed_implicit(nullptr),
     camera_position(0., 2.5, -10.),
@@ -81,13 +88,18 @@ void GlutRender::remove_mesh(Mesh* mesh) {
 }
 
 void GlutRender::add_surface(ImplicitSurface* surf, const Cuboid& box,
-        double resolution)
+        bool always_render, double resolution)
 {
-    surfaces.insert(SurfaceDetails(surf, box, resolution));
+    surfaces.push_back(SurfaceDetails(surf, box, resolution, always_render));
 }
 
 void GlutRender::remove_surface(ImplicitSurface* surf) {
-    surfaces.erase(SurfaceDetails(surf, Cuboid::empty(), 0.1));
+    for(auto it=surfaces.begin(); it != surfaces.end(); ++it) {
+        if(*it == SurfaceDetails(surf, Cuboid::empty(), 0.1, true)) {
+            surfaces.erase(it);
+            break;
+        }
+    }
 }
 
 void GlutRender::run() {
@@ -222,12 +234,16 @@ void GlutRender::display() {
         display_mesh(*mesh);
     }
 
-    for(const SurfaceDetails& surface: surfaces) {
-        Mesh mesh = MarchingCubes(*surface.surface, surface.box,
-                surface.resolution)
-            .add_hint(surface.surface->location_hint())
-            ();
-        display_mesh(mesh);
+    for(SurfaceDetails& surface: surfaces) {
+        if(!surface.always_render) {
+            if(surface.prerender == nullptr)
+                surface.self_render();
+            display_mesh(*surface.prerender);
+        }
+        else {
+            Mesh mesh = surface.render();
+            display_mesh(mesh);
+        }
     }
 
     glutSwapBuffers();
diff --git a/render/GlutRender.hpp b/render/GlutRender.hpp
index cc76fa9..3705014 100644
--- a/render/GlutRender.hpp
+++ b/render/GlutRender.hpp
@@ -5,6 +5,7 @@
 #include "../Mesh.hpp"
 #include "../Implicit.hpp"
 #include <set>
+#include <vector>
 #include <functional>
 
 class GlutRender {
@@ -22,7 +23,7 @@ class GlutRender {
         void add_mesh(Mesh* mesh);
         void remove_mesh(Mesh* mesh);
         void add_surface(ImplicitSurface* surf, const Cuboid& box,
-                double resolution=0.1);
+                bool always_render=true, double resolution=0.1);
         void remove_surface(ImplicitSurface* surf);
         void run();
 
@@ -38,15 +39,29 @@ class GlutRender {
     private:
         struct SurfaceDetails {
             SurfaceDetails(ImplicitSurface* surf, const Cuboid& box,
-                    double resolution):
-                surface(surf), box(box), resolution(resolution) {}
+                    double resolution,
+                    bool always_render):
+                surface(surf), box(box), resolution(resolution),
+                always_render(always_render), prerender(nullptr)
+            {}
+            ~SurfaceDetails() {
+                if(prerender != nullptr)
+                    delete prerender;
+            }
 
             ImplicitSurface* surface;
             Cuboid box;
             double resolution;
 
-            bool operator<(const SurfaceDetails& oth) const {
-                return surface < oth.surface;
+            bool always_render;
+            Mesh* prerender;
+
+            bool operator==(const SurfaceDetails& oth) const {
+                return surface == oth.surface;
+            }
+            Mesh render() const;
+            void self_render() {
+                prerender = new Mesh(render());
             }
         };
 
@@ -71,7 +86,7 @@ class GlutRender {
         std::function<double()> rand_color;
 
         std::set<Mesh*> meshes;
-        std::set<SurfaceDetails> surfaces;
+        std::vector<SurfaceDetails> surfaces;
 
         std::vector<kb_handler_t> kb_handlers;
         std::vector<kb_handler_t> kb_up_handlers;