Renderer: Implement Framebuffers

src/Nazara/OpenGLRenderer/OpenGLFboFramebuffer.cpp

@@ -0,0 +1,92 @@
+// Copyright (C) 2020 Jérôme Leclercq
+// This file is part of the "Nazara Engine - OpenGL Renderer"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <Nazara/OpenGLRenderer/OpenGLFboFramebuffer.hpp>
+#include <Nazara/OpenGLRenderer/OpenGLRenderPass.hpp>
+#include <Nazara/OpenGLRenderer/OpenGLTexture.hpp>
+#include <stdexcept>
+#include <Nazara/OpenGLRenderer/Debug.hpp>
+
+namespace Nz
+{
+	OpenGLFboFramebuffer::OpenGLFboFramebuffer(OpenGLDevice& device, const std::vector<std::shared_ptr<Texture>>& attachments) :
+	OpenGLFramebuffer(OpenGLFramebuffer::Type::FBO)
+	{
+		if (!m_framebuffer.Create(device))
+			throw std::runtime_error("failed to create framebuffer object");
+
+		std::size_t colorAttachmentCount = 0;
+		bool hasDepth = false; 
+		bool hasStencil = false;
+
+		for (std::size_t i = 0; i < attachments.size(); ++i)
+		{
+			assert(attachments[i]);
+			const OpenGLTexture& glTexture = static_cast<const OpenGLTexture&>(*attachments[i]);
+
+			PixelFormat textureFormat = glTexture.GetFormat();
+
+			GLenum attachment;
+			switch (PixelFormatInfo::GetContent(textureFormat))
+			{
+				case PixelFormatContent_ColorRGBA:
+					attachment = GL_COLOR_ATTACHMENT0 + colorAttachmentCount;
+					colorAttachmentCount++;
+					break;
+
+				case PixelFormatContent_Depth:
+					if (hasDepth)
+						throw std::runtime_error("a framebuffer can only have one depth attachment");
+
+					attachment = GL_DEPTH_ATTACHMENT;
+					hasDepth = true;
+					break;
+
+				case PixelFormatContent_DepthStencil:
+					if (hasDepth)
+						throw std::runtime_error("a framebuffer can only have one depth attachment");
+
+					if (hasStencil)
+						throw std::runtime_error("a framebuffer can only have one stencil attachment");
+
+					attachment = GL_DEPTH_STENCIL_ATTACHMENT;
+					hasDepth = true;
+					hasStencil = true;
+					break;
+
+				case PixelFormatContent_Stencil:
+					if (hasStencil)
+						throw std::runtime_error("a framebuffer can only have one stencil attachment");
+
+					attachment = GL_STENCIL_ATTACHMENT;
+					hasStencil = true;
+					break;
+
+				case PixelFormatContent_Undefined:
+				default:
+					throw std::runtime_error("unhandled pixel format " + PixelFormatInfo::GetName(textureFormat));
+			}
+
+			m_framebuffer.Texture2D(attachment, ToOpenGL(OpenGLTexture::ToTextureTarget(glTexture.GetType())), glTexture.GetTexture().GetObjectId());
+		}
+
+		GLenum status = m_framebuffer.Check();
+		if (status != GL_FRAMEBUFFER_COMPLETE)
+			throw std::runtime_error("invalid framebuffer: 0x" + NumberToString(status, 16));
+
+		m_colorAttachmentCount = colorAttachmentCount;
+	}
+
+	void OpenGLFboFramebuffer::Activate() const
+	{
+		const GL::Context& context = m_framebuffer.EnsureDeviceContext();
+
+		context.BindFramebuffer(GL::FramebufferTarget::Draw, m_framebuffer.GetObjectId());
+	}
+
+	std::size_t OpenGLFboFramebuffer::GetColorBufferCount() const
+	{
+		return m_colorAttachmentCount;
+	}
+}