Switch to a deferred lighting based render pipeline

Tidy-up required.

5 files changed, 129 insertions, 5 deletions

diff --git a/ui/gameMainWindow.cpp b/ui/gameMainWindow.cpp
index 84d0ca6..c08588d 100644
--- a/ui/gameMainWindow.cpp
+++ b/ui/gameMainWindow.cpp
@@ -30,7 +30,8 @@ public:
 };
 
 GameMainWindow::GameMainWindow(size_t w, size_t h) :
-	Window {w, h, "I Like Trains"}, camera {{-1250.0F, -1250.0F, 35.0F}, quarter_pi, rdiv(w, h), 0.1F, 10000.0F}
+	Window {w, h, "I Like Trains"}, SceneRenderer {size}, camera {{-1250.0F, -1250.0F, 35.0F}, quarter_pi, rdiv(w, h),
+																  0.1F, 10000.0F}
 {
 	uiComponents.create<ManualCameraController>(glm::vec2 {-1150, -1150});
 	auto gms = uiComponents.create<GameMainSelector>(&camera, glm::vec2 {w, h});
@@ -51,8 +52,10 @@ GameMainWindow::tick(TickDuration)
 void
 GameMainWindow::render() const
 {
-	glEnable(GL_DEPTH_TEST);
-	gameState->world.apply<Renderable>(&Renderable::render, shader);
+	SceneRenderer::render([this] {
+		gameState->world.apply<Renderable>(&Renderable::render, shader);
+		uiComponents.apply<WorldOverlay>(&WorldOverlay::render, shader);
+	});
 	Window::render();
 }
 
diff --git a/ui/gameMainWindow.h b/ui/gameMainWindow.h
index 9cc72ab..2c2c501 100644
--- a/ui/gameMainWindow.h
+++ b/ui/gameMainWindow.h
@@ -3,10 +3,11 @@
 #include "chronology.hpp"
 #include "gfx/gl/camera.h"
 #include "gfx/gl/shader.h"
+#include "sceneRenderer.h"
 #include "window.h"
 #include <cstddef>
 
-class GameMainWindow : public Window {
+class GameMainWindow : public Window, SceneRenderer {
 public:
 	GameMainWindow(size_t w, size_t h);
 
diff --git a/ui/sceneRenderer.cpp b/ui/sceneRenderer.cpp
new file mode 100644
index 0000000..5cd5097
--- /dev/null
+++ b/ui/sceneRenderer.cpp
@@ -0,0 +1,102 @@
+#include "sceneRenderer.h"
+#include <gfx/gl/shaders/fs-lightingShader.h>
+#include <gfx/gl/shaders/vs-lightingShader.h>
+
+SceneRenderer::SceneRenderer(glm::ivec2 size) : lighting {lightingShader_vs.compile(), lightingShader_fs.compile()}
+{
+	glBindFramebuffer(GL_FRAMEBUFFER, gBuffer);
+	const auto configuregdata
+			= [size](const GLuint data, const GLint format, const GLenum type, const GLenum attachment) {
+				  glBindTexture(GL_TEXTURE_2D, data);
+				  glTexImage2D(GL_TEXTURE_2D, 0, format, size.x, size.y, 0, GL_RGBA, type, NULL);
+				  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+				  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+				  glFramebufferTexture2D(GL_FRAMEBUFFER, attachment, GL_TEXTURE_2D, data, 0);
+			  };
+	configuregdata(gPosition, GL_RGBA16F, GL_FLOAT, GL_COLOR_ATTACHMENT0);
+	configuregdata(gNormal, GL_RGBA16F, GL_FLOAT, GL_COLOR_ATTACHMENT1);
+	configuregdata(gAlbedoSpec, GL_RGBA, GL_UNSIGNED_BYTE, GL_COLOR_ATTACHMENT2);
+	static constexpr std::array<unsigned int, 3> attachments {
+			GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2};
+	glDrawBuffers(attachments.size(), attachments.data());
+
+	glBindRenderbuffer(GL_RENDERBUFFER, depth);
+	glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, size.x, size.y);
+	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depth);
+
+	// finally check if framebuffer is complete
+	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
+		throw std::runtime_error("Framebuffer not complete!");
+	}
+	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+}
+
+unsigned int quadVAO = 0;
+unsigned int quadVBO;
+void
+renderQuad()
+{
+	if (quadVAO == 0) {
+		float quadVertices[] = {
+				// positions        // texture Coords
+				-1.0f,
+				1.0f,
+				0.0f,
+				0.0f,
+				1.0f,
+				-1.0f,
+				-1.0f,
+				0.0f,
+				0.0f,
+				0.0f,
+				1.0f,
+				1.0f,
+				0.0f,
+				1.0f,
+				1.0f,
+				1.0f,
+				-1.0f,
+				0.0f,
+				1.0f,
+				0.0f,
+		};
+		// setup plane VAO
+		glGenVertexArrays(1, &quadVAO);
+		glGenBuffers(1, &quadVBO);
+		glBindVertexArray(quadVAO);
+		glBindBuffer(GL_ARRAY_BUFFER, quadVBO);
+		glBufferData(GL_ARRAY_BUFFER, sizeof(quadVertices), &quadVertices, GL_STATIC_DRAW);
+		glEnableVertexAttribArray(0);
+		glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), nullptr);
+		glEnableVertexAttribArray(1);
+		glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), reinterpret_cast<void *>(3 * sizeof(float)));
+	}
+	glBindVertexArray(quadVAO);
+	glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+	glBindVertexArray(0);
+}
+
+void
+SceneRenderer::render(std::function<void()> content) const
+{
+	glEnable(GL_BLEND);
+	glEnable(GL_DEPTH_TEST);
+	// Geometry pass
+	glBindFramebuffer(GL_FRAMEBUFFER, gBuffer);
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+	content();
+	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+	// Lighting pass
+	glDisable(GL_BLEND);
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+	glUseProgram(lighting.m_program);
+	glActiveTexture(GL_TEXTURE0);
+	glBindTexture(GL_TEXTURE_2D, gPosition);
+	glActiveTexture(GL_TEXTURE1);
+	glBindTexture(GL_TEXTURE_2D, gNormal);
+	glActiveTexture(GL_TEXTURE2);
+	glBindTexture(GL_TEXTURE_2D, gAlbedoSpec);
+	// TODO Configure lights
+	renderQuad();
+}
diff --git a/ui/sceneRenderer.h b/ui/sceneRenderer.h
new file mode 100644
index 0000000..2e1c372
--- /dev/null
+++ b/ui/sceneRenderer.h
@@ -0,0 +1,18 @@
+#pragma once
+
+#include "gfx/gl/shader.h"
+#include "lib/glArrays.h"
+#include <functional>
+
+class SceneRenderer {
+public:
+	SceneRenderer(glm::ivec2 size);
+
+	void render(std::function<void()> content) const;
+
+private:
+	glFrameBuffer gBuffer;
+	glTexture gPosition, gNormal, gAlbedoSpec;
+	glRenderBuffer depth;
+	ProgramHandleBase lighting;
+};
diff --git a/ui/window.cpp b/ui/window.cpp
index 419abc3..82f4d40 100644
--- a/ui/window.cpp
+++ b/ui/window.cpp
@@ -94,7 +94,7 @@ Window::refresh() const
 void

 Window::render() const

 {

-	uiComponents.apply<WorldOverlay>(&WorldOverlay::render, getShader());

+	glEnable(GL_BLEND);

 	glDisable(GL_DEPTH_TEST);

 	uiComponents.apply(&UIComponent::render, uiShader, UIComponent::Position {});

 }