Switch to a deferred lighting based render pipeline

Tidy-up required.

1 files changed, 102 insertions, 0 deletions

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();
+}