2 files changed, 195 insertions, 0 deletions
diff --git a/gfx/gl/sceneRenderer.cpp b/gfx/gl/sceneRenderer.cpp
new file mode 100644
index 0000000..a97387e
--- /dev/null
+++ b/gfx/gl/sceneRenderer.cpp
@@ -0,0 +1,140 @@
+#include "sceneRenderer.h"
+#include "maths.h"
+#include <gfx/gl/shaders/fs-directionalLight.h>
+#include <gfx/gl/shaders/fs-lightingShader.h>
+#include <gfx/gl/shaders/vs-lightingShader.h>
+#include <glm/gtc/type_ptr.hpp>
+
+static constexpr std::array<glm::vec4, 4> displayVAOdata {{
+		// positions(x,y) texture coords(z,w)
+		{-1.0f, 1.0f, 0.0f, 1.0f},
+		{-1.0f, -1.0f, 0.0f, 0.0f},
+		{1.0f, 1.0f, 1.0f, 1.0f},
+		{1.0f, -1.0f, 1.0f, 0.0f},
+}};
+SceneRenderer::SceneRenderer(glm::ivec2 s, GLuint o) :
+	camera {{-1250.0F, -1250.0F, 35.0F}, quarter_pi, ratio(s), 0.1F, 10000.0F}, size {s}, output {o},
+	lighting {lightingShader_vs, lightingShader_fs}
+{
+	shader.setViewPort({0, 0, size.x, size.y});
+	glBindVertexArray(displayVAO);
+	glBindBuffer(GL_ARRAY_BUFFER, displayVBO);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(displayVAOdata), nullptr, GL_STATIC_DRAW);
+	glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(displayVAOdata), glm::value_ptr(displayVAOdata.front()));
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, sizeof(glm::vec4), nullptr);
+
+	glBindFramebuffer(GL_FRAMEBUFFER, gBuffer);
+	const auto configuregdata
+			= [this](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);
+	configuregdata(gIllumination, GL_RGBA16F, GL_FLOAT, GL_COLOR_ATTACHMENT3);
+
+	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, output);
+}
+
+void
+SceneRenderer::render(const SceneProvider & scene) const
+{
+	shader.setViewProjection(camera.GetViewProjection());
+	glViewport(0, 0, size.x, size.y);
+
+	// Geometry pass
+	glBindFramebuffer(GL_FRAMEBUFFER, gBuffer);
+	static constexpr std::array<unsigned int, 3> attachments {
+			GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2};
+	glDrawBuffers(attachments.size(), attachments.data());
+	glEnable(GL_BLEND);
+	glEnable(GL_CULL_FACE);
+	glCullFace(GL_BACK);
+	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+	glEnable(GL_DEPTH_TEST);
+	glClearColor(0, 0, 0, 1);
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+	scene.content(shader);
+
+	// Illumination pass
+	glDrawBuffer(GL_COLOR_ATTACHMENT3);
+	glDisable(GL_DEPTH_TEST);
+	glEnable(GL_BLEND);
+	glBlendFunc(GL_ONE, GL_ONE);
+	glActiveTexture(GL_TEXTURE0);
+	glBindTexture(GL_TEXTURE_2D, gPosition);
+	glActiveTexture(GL_TEXTURE1);
+	glBindTexture(GL_TEXTURE_2D, gNormal);
+	scene.environment(shader, *this);
+	scene.lights(shader);
+
+	// Lighting pass
+	glBindFramebuffer(GL_FRAMEBUFFER, output);
+	glDisable(GL_BLEND);
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+	glActiveTexture(GL_TEXTURE0);
+	glBindTexture(GL_TEXTURE_2D, gPosition);
+	glActiveTexture(GL_TEXTURE1);
+	glBindTexture(GL_TEXTURE_2D, gNormal);
+	glActiveTexture(GL_TEXTURE2);
+	glBindTexture(GL_TEXTURE_2D, gAlbedoSpec);
+	glActiveTexture(GL_TEXTURE3);
+	glBindTexture(GL_TEXTURE_2D, gIllumination);
+	lighting.use();
+	glBindVertexArray(displayVAO);
+	glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+	glBindVertexArray(0);
+}
+
+void
+SceneRenderer::setAmbientLight(const glm::vec3 & colour) const
+{
+	glClearColor(colour.r, colour.g, colour.b, 1.0F);
+	glClear(GL_COLOR_BUFFER_BIT);
+}
+
+void
+SceneRenderer::setDirectionalLight(const glm::vec3 & colour, const glm::vec3 & direction) const
+{
+	if (colour.r > 0 || colour.g > 0 || colour.b > 0) {
+		dirLight.use();
+		dirLight.setDirectionalLight(colour, direction);
+		glBindVertexArray(displayVAO);
+		glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+		glBindVertexArray(0);
+	}
+}
+
+SceneRenderer::DirectionalLightProgram::DirectionalLightProgram() :
+	Program {lightingShader_vs, directionalLight_fs}, directionLoc {*this, "lightDirection"}, colourLoc {*this,
+																									  "lightColour"}
+{
+}
+
+void
+SceneRenderer::DirectionalLightProgram::setDirectionalLight(const glm::vec3 & c, const glm::vec3 & d) const
+{
+	glUniform3fv(colourLoc, 1, glm::value_ptr(c));
+	const auto nd = glm::normalize(d);
+	glUniform3fv(directionLoc, 1, glm::value_ptr(nd));
+}
+
+void
+SceneRenderer::SceneProvider::environment(const SceneShader &, const SceneRenderer & renderer) const
+{
+	renderer.setAmbientLight({0.5F, 0.5F, 0.5F});
+	renderer.setDirectionalLight({0.6F, 0.6F, 0.6F}, {1, 0, -1});
+}
diff --git a/gfx/gl/sceneRenderer.h b/gfx/gl/sceneRenderer.h
new file mode 100644
index 0000000..f40b894
--- /dev/null
+++ b/gfx/gl/sceneRenderer.h
@@ -0,0 +1,55 @@
+#pragma once
+
+#include "gfx/gl/camera.h"
+#include "gfx/gl/program.h"
+#include "gfx/gl/sceneShader.h"
+#include "lib/glArrays.h"
+#include <functional>
+#include <glm/fwd.hpp>
+
+class SceneRenderer {
+public:
+	class SceneProvider {
+	public:
+		virtual ~SceneProvider() = default;
+		virtual void content(const SceneShader &) const = 0;
+		virtual void environment(const SceneShader &, const SceneRenderer &) const;
+		virtual void lights(const SceneShader &) const = 0;
+	};
+
+	explicit SceneRenderer(glm::ivec2 size, GLuint output);
+
+	void render(const SceneProvider &) const;
+	void setAmbientLight(const glm::vec3 & colour) const;
+	void setDirectionalLight(const glm::vec3 & colour, const glm::vec3 & direction) const;
+
+	Camera camera;
+
+private:
+	glm::ivec2 size;
+	GLuint output;
+	glFrameBuffer gBuffer;
+	glTexture gPosition, gNormal, gAlbedoSpec, gIllumination;
+	glRenderBuffer depth;
+	class DeferredLightProgram : public Program {
+	public:
+		using Program::Program;
+		using Program::use;
+	};
+	class DirectionalLightProgram : public Program {
+	public:
+		DirectionalLightProgram();
+		using Program::use;
+
+		void setDirectionalLight(const glm::vec3 &, const glm::vec3 &) const;
+
+	private:
+		RequiredUniformLocation directionLoc, colourLoc;
+	};
+
+	DeferredLightProgram lighting;
+	DirectionalLightProgram dirLight;
+	glVertexArray displayVAO;
+	glBuffer displayVBO;
+	SceneShader shader;
+};