[Performous-commit] Lasse Karkkainen : Huge performance improvement (for Nvidia) by not generating mipmaps for FBO.

[Lasse Kärkkäi. <tr...@us...>]

Module: performous
Branch: opengl2
Commit: baaf59b8a5247cacaff173de8b04712772b761f4

Author: Lasse Karkkainen <tro...@tr...>
Date:   Sun Feb  6 00:12:02 2011 +0100

Huge performance improvement (for Nvidia) by not generating mipmaps for FBO.

---

 game/fbo.hh          |   14 ++++----------
 game/video_driver.cc |    3 +--
 2 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/game/fbo.hh b/game/fbo.hh
index 77a58d2..f511a99 100644
--- a/game/fbo.hh
+++ b/game/fbo.hh
@@ -11,19 +11,13 @@ class FBO: public boost::noncopyable {
 	FBO(): m_texture() {
 		{
 			UseTexture tex(m_texture);
-			glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, screenW(), screenH(), 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
-			glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
-			// When texture area is large, bilinear filter the original
-			glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-			// The texture wraps over at the edges (repeat)
-			glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
-			glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+			glTexImage2D(GL_TEXTURE_RECTANGLE, 0, GL_RGBA, screenW(), screenH(), 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 		}
 		// Create FBO
 		glGenFramebuffersEXT(1, &m_fbo);
 		// Bind texture as COLOR_ATTACHMENT0
 		bind();
-		glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, m_texture.id(), 0);
+		glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_RECTANGLE, m_texture.id(), 0);
 		unbind();
 	}
 	/// Handle clean-up
@@ -31,7 +25,7 @@ class FBO: public boost::noncopyable {
 		if (m_fbo) glDeleteFramebuffersEXT(1, &m_fbo);
 	}
 	/// Returns a reference to the attached texture
-	OpenGLTexture<GL_TEXTURE_2D>& getTexture() {
+	OpenGLTexture<GL_TEXTURE_RECTANGLE>& getTexture() {
 		return m_texture;
 	}
 	/// Bind the FBO into use
@@ -45,7 +39,7 @@ class FBO: public boost::noncopyable {
 
   private:
 	GLuint m_fbo;
-	OpenGLTexture<GL_TEXTURE_2D> m_texture;
+	OpenGLTexture<GL_TEXTURE_RECTANGLE> m_texture;
 };
 
 /// RAII FBO binder
diff --git a/game/video_driver.cc b/game/video_driver.cc
index 337c939..97da256 100644
--- a/game/video_driver.cc
+++ b/game/video_driver.cc
@@ -132,8 +132,7 @@ void Window::render(boost::function<void (void)> drawFunc) {
 		}
 		{
 			UseTexture use(fbo[num].getTexture());
-			glGenerateMipmap(GL_TEXTURE_2D);
-			fbo[num].getTexture().draw(Dimensions().stretch(1.0, virtH()), TexCoords(0.0, 1.0, 1.0, 0.0));
+			fbo[num].getTexture().draw(Dimensions().stretch(1.0, virtH()), TexCoords(0.0, screenH(), screenW(), 0.0));
 		}
 	}
 }