From b106c1c028c57fc489368122f21b9f01d56c81a1 Mon Sep 17 00:00:00 2001
From: Dusan Maliarik <dusan@struna.me>
Date: Mon, 22 Jun 2020 23:43:06 -0600
Subject: [PATCH] Support count setter

---
 src/magnum_render.cpp | 35 +++++++++++++++------
 src/magnum_render.h   | 71 +++++++++++++++++++++++--------------------
 2 files changed, 63 insertions(+), 43 deletions(-)

diff --git a/src/magnum_render.cpp b/src/magnum_render.cpp
index 59e1150..40ae3d3 100644
--- a/src/magnum_render.cpp
+++ b/src/magnum_render.cpp
@@ -16,12 +16,14 @@ static const auto HUE_BG = 210.0_degf;
 static const auto COLOR_BG = Color4::fromHsv({HUE_BG, .3f, .9f}, 1.f);
 static const auto COLOR_GRID = Color4::fromHsv({HUE_BG, .3f, .7f}, 1.f);
 
-MagnumRenderer::MagnumRenderer() {}
+MagnumRenderer::MagnumRenderer() :
+  m_init(false),
+  m_count(1) {}
 
 MagnumRenderer::~MagnumRenderer() {}
 
 void MagnumRenderer::t(const float t) {
-  if (m_subjectObject != nullptr) {
+  if (m_subjectObject != nullptr && m_subjectObject->parent()) {
     m_subjectObject->resetTransformation();
     m_subjectObject->translate(Vector3{0.f, 1.f, 0.f});
     m_subjectObject->rotateY(Rad(t*Math::Constants<float>::pi()));
@@ -38,7 +40,8 @@ void MagnumRenderer::hue(float hue) {
 }
 
 void MagnumRenderer::count(int count) {
-  m_count = count;
+  if (m_subjectDrawable)
+    m_subjectDrawable->count(count);
 }
 
 void MagnumRenderer::lazyInitialize() {
@@ -56,19 +59,19 @@ void MagnumRenderer::lazyInitialize() {
       .setLightColor(Color3{1.f})
       .setLightPosition(Vector3{-100.f, 100.f, 50.f});
 
-    new SubjectDrawable{*m_subjectObject, m_subjectShader, m_subject, m_drawables};
+    m_subjectDrawable = new SubjectDrawable{*m_subjectObject, m_subjectShader, m_subject, m_drawables, m_count};
   }
 
   // The Grid
   {
     m_grid = MeshTools::compile(Primitives::grid3DWireframe({15, 15}));
-    auto obj = new Object3D{&m_scene};
-    (*obj).rotateX(90.0_degf).scale(Vector3{8.0f});
+    m_gridObject = new Object3D{&m_scene};
+    (*m_gridObject).rotateX(90.0_degf).scale(Vector3{8.0f});
 
     m_gridShader = Shaders::Flat3D{};
     m_gridShader.setColor(COLOR_GRID);
 
-    new GridDrawable{*obj, m_gridShader, m_grid, m_drawables};
+    new GridDrawable{*m_gridObject, m_gridShader, m_grid, m_drawables};
   }
 
   // The Camera
@@ -142,8 +145,20 @@ void GridDrawable::draw(const Matrix4 &transformation,
 void SubjectDrawable::draw(const Matrix4 &transformation,
                            SceneGraph::Camera3D &camera) {
   m_shader
-      .setTransformationMatrix(transformation)
       .setNormalMatrix(transformation.normalMatrix())
-      .setProjectionMatrix(camera.projectionMatrix())
-      .draw(m_mesh);
+      .setProjectionMatrix(camera.projectionMatrix());
+  static const float width = 3.f;
+  float x = -float(m_count)/2.f * width + width/2.f;
+  for (int i = 0; i < m_count; i++) {
+    m_shader
+        .setTransformationMatrix(
+          transformation *
+          Matrix4::translation({x, 0.f, 0.f}))
+        .draw(m_mesh);
+    x += width;
+  }
+}
+
+void SubjectDrawable::count(int count) {
+  m_count = count;
 }
diff --git a/src/magnum_render.h b/src/magnum_render.h
index 8485288..33d8ed1 100644
--- a/src/magnum_render.h
+++ b/src/magnum_render.h
@@ -19,6 +19,40 @@ using namespace Magnum;
 using Object3D = SceneGraph::Object<SceneGraph::MatrixTransformation3D>;
 using Scene3D = SceneGraph::Scene<SceneGraph::MatrixTransformation3D>;
 
+class GridDrawable : public SceneGraph::Drawable3D {
+public:
+  explicit GridDrawable(Object3D &object, Shaders::Flat3D &shader,
+                        GL::Mesh &mesh, SceneGraph::DrawableGroup3D &drawables)
+    : SceneGraph::Drawable3D{object, &drawables},
+      m_shader(shader),
+      m_mesh(mesh) {}
+
+  void draw(const Matrix4 &transformation, SceneGraph::Camera3D &camera);
+
+private:
+  Shaders::Flat3D &m_shader;
+  GL::Mesh &m_mesh;
+};
+
+class SubjectDrawable : public SceneGraph::Drawable3D {
+public:
+  explicit SubjectDrawable(Object3D &object, Shaders::Phong &shader,
+                           GL::Mesh &mesh, SceneGraph::DrawableGroup3D &drawables,
+                           int count)
+      : SceneGraph::Drawable3D{object, &drawables},
+        m_shader(shader),
+        m_mesh(mesh),
+        m_count(count) {}
+
+  void draw(const Matrix4 &transformation, SceneGraph::Camera3D &camera);
+  void count(int count);
+
+private:
+  Shaders::Phong &m_shader;
+  GL::Mesh &m_mesh;
+  int m_count;
+};
+
 class MagnumRenderer {
 public:
   MagnumRenderer();
@@ -39,9 +73,8 @@ private:
   void lazyInitialize();
   void prepGLState();
 
-  bool m_init{false};
-
-  float m_count{1};
+  bool m_init;
+  int m_count;
 
   Platform::GLContext *m_ctx;
   GL::Framebuffer m_FBO{NoCreate};
@@ -53,39 +86,11 @@ private:
   GL::Mesh m_subject{NoCreate};
   Shaders::Phong m_subjectShader{NoCreate};
   Object3D* m_subjectObject{nullptr};
+  SubjectDrawable* m_subjectDrawable{nullptr};
 
   GL::Mesh m_grid{NoCreate};
   Shaders::Flat3D m_gridShader{NoCreate};
-};
-
-class GridDrawable : public SceneGraph::Drawable3D {
-public:
-  explicit GridDrawable(Object3D &object, Shaders::Flat3D &shader,
-                        GL::Mesh &mesh, SceneGraph::DrawableGroup3D &drawables)
-    : SceneGraph::Drawable3D{object, &drawables},
-      m_shader(shader),
-      m_mesh(mesh) {}
-
-  void draw(const Matrix4 &transformation, SceneGraph::Camera3D &camera);
-
-private:
-  Shaders::Flat3D &m_shader;
-  GL::Mesh &m_mesh;
-};
-
-class SubjectDrawable : public SceneGraph::Drawable3D {
-public:
-  explicit SubjectDrawable(Object3D &object, Shaders::Phong &shader,
-                           GL::Mesh &mesh, SceneGraph::DrawableGroup3D &drawables)
-      : SceneGraph::Drawable3D{object, &drawables},
-        m_shader(shader),
-        m_mesh(mesh) {}
-
-  void draw(const Matrix4 &transformation, SceneGraph::Camera3D &camera);
-
-private:
-  Shaders::Phong &m_shader;
-  GL::Mesh &m_mesh;
+  Object3D* m_gridObject{nullptr};
 };
 
 #endif // MAGNUM_RENDER_H