[Performous-commit] Tapio Vierros : Preliminary Frame Buffer Object class.

[Tapio V. <aa...@us...>]

Module: performous
Branch: opengl2
Commit: 5c22b0385edcf3fe5d98a13aed4da2dd3b31c932

Author: Tapio Vierros <tap...@gm...>
Date:   Sat Nov  6 15:22:29 2010 +0200

Preliminary Frame Buffer Object class.

---

 game/fbo.hh |   46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 46 insertions(+), 0 deletions(-)

diff --git a/game/fbo.hh b/game/fbo.hh
new file mode 100644
index 0000000..4199393
--- /dev/null
+++ b/game/fbo.hh
@@ -0,0 +1,46 @@
+#pragma once
+
+#include "video_driver.hh"
+
+/// Frame Buffer Object class
+class FBO {
+  public:
+	/// Generate the FBO and attach a fresh texture to it
+	FBO(): m_texture() {
+		glGenFramebuffersEXT(1, &m_fbo);
+		bind();
+		{
+			UseTexture tex(m_texture);
+			glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGBA, screenW(), screenH(), 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+			// Bind texture as COLOR_ATTACHMENT0
+			glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_RECTANGLE_ARB, m_texture.id(), 0);
+		}
+		unbind();
+	}
+	/// Handle clean-up
+	~FBO() {
+		if (m_fbo) glDeleteFramebuffersEXT(1, &m_fbo);
+	}
+	/// Returns a reference to the attached texture
+	OpenGLTexture<GL_TEXTURE_RECTANGLE_ARB>& getTexture() {
+		return m_texture;
+	}
+	/// Bind the FBO into use
+	void bind() { 
+		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, m_fbo);
+	}
+	/// Unbind any FBO
+	static void unbind() {
+		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+	}
+
+  private:
+	GLuint m_fbo;
+	OpenGLTexture<GL_TEXTURE_RECTANGLE_ARB> m_texture;
+};
+
+/// RAII FBO binder
+struct UseFBO {
+	UseFBO(FBO& fbo) { fbo.bind(); }
+	~UseFBO() { FBO::unbind(); }
+};