Added a basic grid renderer for XZ plane. #56

CMakeLists.txt

@@ -181,6 +181,8 @@ PRIVATE ImGui
 add_library(OpenGL
 source/OpenGL/OpenGLRenderer.hpp
 source/OpenGL/OpenGLRenderer.cpp
+source/OpenGL/GridRenderer.hpp
+source/OpenGL/GridRenderer.cpp
 source/OpenGL/DebugRenderer.hpp
 source/OpenGL/DebugRenderer.cpp
 source/OpenGL/GLState.hpp

source/Application.cpp

@@ -7,6 +7,7 @@ Application::Application(Platform::Input& p_input, Platform::Window& p_window) n
     , mMeshSystem{mTextureSystem}
     , mSceneSystem{mTextureSystem, mMeshSystem}
     , mOpenGLRenderer{m_window, mSceneSystem, mMeshSystem, mTextureSystem}
+    , m_grid_renderer{}
     , mCollisionSystem{mSceneSystem, mMeshSystem}
     , mPhysicsSystem{mSceneSystem, mCollisionSystem}
     , mInputSystem{m_input, m_window, mSceneSystem}

source/Application.hpp

@@ -19,6 +19,7 @@
 // OpenGL
 #include "OpenGLRenderer.hpp"
 #include "DebugRenderer.hpp"
+#include "OpenGL/GridRenderer.hpp"
 
 // Utility
 #include "File.hpp"
@@ -50,6 +51,7 @@ class Application
     System::SceneSystem mSceneSystem;
 
     OpenGL::OpenGLRenderer mOpenGLRenderer;
+    OpenGL::GridRenderer m_grid_renderer;
 
     System::CollisionSystem mCollisionSystem;
     System::PhysicsSystem mPhysicsSystem;
@@ -129,6 +131,7 @@ class Application
                 m_window.start_ImGui_frame();
                 mOpenGLRenderer.start_frame();
 
+                m_grid_renderer.draw();
                 mOpenGLRenderer.draw();
                 mEditor.draw(durationSinceLastRenderTick);
                 OpenGL::DebugRenderer::render(mSceneSystem);

source/OpenGL/GLSL/grid.frag

@@ -0,0 +1,9 @@
+#version 330 core
+
+in vec4 FragmentColour;
+out vec4 Colour;
+
+void main()
+{
+	Colour = FragmentColour;
+}

source/OpenGL/GLSL/grid.vert

@@ -0,0 +1,19 @@
+#version 420 core
+
+layout (location = 0) in vec3 VertexPosition;
+
+layout(shared) uniform ViewProperties
+{
+    mat4 view;
+    mat4 projection;
+} viewProperties;
+
+uniform vec4 colour;
+
+out vec4 FragmentColour;
+
+void main()
+{
+    gl_Position    = viewProperties.projection * viewProperties.view * vec4(VertexPosition, 1.0);
+	FragmentColour = colour;
+}

source/OpenGL/GridRenderer.cpp

@@ -0,0 +1,44 @@
+#include "GridRenderer.hpp"
+
+namespace OpenGL
+{
+    GridRenderer::GridRenderer() noexcept
+        : m_line_points{}
+        , m_colour{1.f, 1.f, 1.f, 0.7f}
+        , m_grid_shader{"grid"}
+        , m_line_VAO{}
+        , m_line_VBO{}
+    {
+        constexpr int Count = 1000;
+        constexpr int Size  = 100; // #Todo Should be camera z-far
+        m_line_points.reserve(Count * 8);
+
+        // XZ-plane
+        for (auto i = -Count; i <= Count; i++)
+        {
+            m_line_points.push_back({glm::vec3{-Size, 0.f, i}});
+            m_line_points.push_back({glm::vec3{Size, 0.f, i}});
+            m_line_points.push_back({glm::vec3{i, 0.f, Size}});
+            m_line_points.push_back({glm::vec3{i, 0.f, -Size}});
+        }
+
+        m_line_VAO.bind();
+        m_line_VBO.set_data(m_line_points);
+    }
+    void GridRenderer::draw()
+    {
+        if (!m_line_points.empty())
+        {
+            m_grid_shader.use();
+            m_grid_shader.set_uniform("colour", m_colour);
+            toggle_cull_face(false);
+            set_depth_test(true);
+            set_depth_test_type(DepthTestType::Less);
+            set_polygon_mode(PolygonMode::Fill);
+
+            m_line_VAO.bind();
+            m_line_VBO.bind();
+            draw_arrays(PrimitiveMode::Lines, 0, static_cast<GLsizei>(m_line_points.size() * 2));
+        }
+    }
+}

source/OpenGL/GridRenderer.hpp

@@ -0,0 +1,30 @@
+#include "OpenGL/Types.hpp"
+#include "OpenGL/Shader.hpp"
+
+#include "glm/vec3.hpp"
+#include "glm/vec4.hpp"
+
+#include <array>
+#include <vector>
+
+namespace OpenGL
+{
+    class GridRenderer
+    {
+        struct GridVert
+        {
+            constexpr inline static std::array<VertexAttribute, 1> Attributes = { VertexAttribute::Position3D };
+            glm::vec3 m_position = glm::vec3{0.f};
+        };
+
+        std::vector<GridVert> m_line_points;
+        glm::vec4 m_colour;
+        Shader m_grid_shader;
+        VAO m_line_VAO;
+        VBO m_line_VBO;
+
+    public:
+        GridRenderer() noexcept;
+        void draw();
+    };
+}