[Performous-commit] Lasse Karkkainen : Enable sRGB framebuffer and textures for proper gamma-correct blending ( if sRGB is available), glColor values need to be made darker now. Using floating-point linear formats in FBOs.

[Lasse Kärkkäi. <tr...@us...>]

Author: Lasse Karkkainen <tro...@tr...>
Date:   Fri Jul  8 11:20:59 2011 +0300

Enable sRGB framebuffer and textures for proper gamma-correct blending (if sRGB is available), glColor values need to be made darker now. Using floating-point linear formats in FBOs.

---

 game/fbo.hh          |    4 ++--
 game/surface.cc      |    7 ++++---
 game/video_driver.cc |    1 +
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/game/fbo.hh b/game/fbo.hh
index f3773bd..856695a 100644
--- a/game/fbo.hh
+++ b/game/fbo.hh
@@ -11,11 +11,11 @@ class FBO: boost::noncopyable {
 	FBO(unsigned w, unsigned h) {
 		{
 			UseTexture tex(m_texture);
-			glTexImage2D(GL_TEXTURE_RECTANGLE, 0, GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+			glTexImage2D(GL_TEXTURE_RECTANGLE, 0, GL_RGBA, w, h, 0, GL_RGBA, GL_FLOAT, NULL);
 		}
 		{
 			UseTexture tex(m_depth);
-			glTexImage2D(GL_TEXTURE_RECTANGLE, 0, GL_DEPTH_COMPONENT24, w, h, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_INT, NULL);
+			glTexImage2D(GL_TEXTURE_RECTANGLE, 0, GL_DEPTH_COMPONENT, w, h, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_INT, NULL);
 		}
 		// Create FBO
 		glGenFramebuffersEXT(1, &m_fbo);
diff --git a/game/surface.cc b/game/surface.cc
index d24ca16..5b7078b 100644
--- a/game/surface.cc
+++ b/game/surface.cc
@@ -79,6 +79,7 @@ namespace {
 		if (it != pixFormats.m.end()) return it->second;
 		throw std::logic_error("Unknown pixel format");
 	}
+	GLint internalFormat() { return GL_EXT_framebuffer_sRGB ? GL_SRGB_ALPHA : GL_RGBA; }
 }
 
 void Texture::load(unsigned int width, unsigned int height, pix::Format format, unsigned char const* buffer, float ar) {
@@ -103,7 +104,7 @@ void Texture::load(unsigned int width, unsigned int height, pix::Format format,
 	glPixelStorei(GL_UNPACK_SWAP_BYTES, f.swap);
 	// Load the data into texture
 	if ((isPow2(width) && isPow2(height)) || GLEW_ARB_texture_non_power_of_two) { // Can directly load the texture
-		glTexImage2D(type(), 0, GL_RGBA, width, height, 0, f.format, f.type, buffer);
+		glTexImage2D(type(), 0, internalFormat(), width, height, 0, f.format, f.type, buffer);
 	} else {
 		int newWidth = prevPow2(width);
 		int newHeight = prevPow2(height);
@@ -114,7 +115,7 @@ void Texture::load(unsigned int width, unsigned int height, pix::Format format,
 		// (1) no repeat => cannot texture
 		// (2) coordinates not normalized => would require special hackery elsewhere
 		// Just don't do it in Surface class, thanks. -Tronic
-		glTexImage2D(type(), 0, GL_RGBA, newWidth, newHeight, 0, f.format, f.type, &outBuf[0]);
+		glTexImage2D(type(), 0, internalFormat(), newWidth, newHeight, 0, f.format, f.type, &outBuf[0]);
 	}
 	glGenerateMipmap(type());
 }
@@ -129,7 +130,7 @@ void Surface::load(unsigned int width, unsigned int height, pix::Format format,
 	UseTexture texture(m_texture);
 	PixFmt const& f = getPixFmt(format);
 	glPixelStorei(GL_UNPACK_SWAP_BYTES, f.swap);
-	glTexImage2D(m_texture.type(), 0, GL_RGBA, width, height, 0, f.format, f.type, buffer);
+	glTexImage2D(m_texture.type(), 0, internalFormat(), width, height, 0, f.format, f.type, buffer);
 }
 
 void Surface::draw() const {
diff --git a/game/video_driver.cc b/game/video_driver.cc
index 568e219..6a92ce1 100644
--- a/game/video_driver.cc
+++ b/game/video_driver.cc
@@ -244,6 +244,7 @@ void Window::view(unsigned num) {
 	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
 	glShadeModel(GL_SMOOTH);
 	glEnable(GL_BLEND);
+	if (GL_EXT_framebuffer_sRGB) glEnable(GL_FRAMEBUFFER_SRGB);
 	shader("color").bind();
 	// Setup views
 	double vx = 0.5f * (screen->w - s_width);