Game Engine: alpha blending and sorting

=======================================

Alpha blending + sorting was revised, to fix bugs and get it
to work more predictable.

* A new per texture face "Sort" setting defines if the face
  is alpha sorted or not, instead of abusing the "ZTransp"
  setting as it did before.
* Existing files are converted to hopefully match the old
  behavior as much as possible with a version patch.
* On new meshes the Sort flag is disabled by the default, to
  avoid unexpected and hard to find slowdowns.
* Alpha sorting for faces was incredibly slow. Sorting faces
  in a mesh with 600 faces lowered the framerate from 200 to
  70 fps in my test.. the sorting there case goes about 15x
  faster now, but it is still advised to use Clip Alpha if
  possible instead of regular Alpha.
* There still various limitations in the alpha sorting code,
  I've added some comments to the code about this.

Some docs at the bottom of the page:
http://www.blender.org/development/current-projects/changes-since-246/realtime-glsl-materials/

Merged some fixes from the apricot branch, most important
change is that  tangents are now exactly the same as the rest
of Blender, instead of being computed in the game engine with a
different algorithm.

Also, the subversion was bumped to 1.

1 files changed, 78 insertions, 43 deletions

diff --git a/source/gameengine/Ketsji/KX_BlenderMaterial.cpp b/source/gameengine/Ketsji/KX_BlenderMaterial.cpp
index 0f445a9f32e..a67e5b26667 100644
--- a/source/gameengine/Ketsji/KX_BlenderMaterial.cpp
+++ b/source/gameengine/Ketsji/KX_BlenderMaterial.cpp
@@ -38,6 +38,7 @@ extern "C" {
 // ------------------------------------
 #define spit(x) std::cout << x << std::endl;
 
+BL_Shader *KX_BlenderMaterial::mLastShader = NULL;
 BL_BlenderShader *KX_BlenderMaterial::mLastBlenderShader = NULL;
 
 //static PyObject *gTextureDict = 0;
@@ -58,7 +59,8 @@ KX_BlenderMaterial::KX_BlenderMaterial(
 		data->tilexrep[0],
 		data->tileyrep[0],
 		data->mode,
-		((data->ras_mode &TRANSP)!=0),
+		data->transp,
+		((data->ras_mode &ALPHA)!=0),
 		((data->ras_mode &ZSORT)!=0),
 		lightlayer,
 		((data->ras_mode &TRIANGLE)!=0),
@@ -79,7 +81,6 @@ KX_BlenderMaterial::KX_BlenderMaterial(
 	m_flag |=RAS_BLENDERMAT;
 	m_flag |=(mMaterial->IdMode>=ONETEX)?RAS_MULTITEX:0;
 	m_flag |=(mMaterial->ras_mode & USE_LIGHT)!=0?RAS_MULTILIGHT:0;
-	m_flag |=(mMaterial->ras_mode &ALPHA_TEST)!=0?RAS_FORCEALPHA:0;
 
 	// figure max
 	int enabled = mMaterial->num_enabled;
@@ -158,12 +159,29 @@ void KX_BlenderMaterial::OnConstruction()
 	mConstructed = true;
 }
 
+void KX_BlenderMaterial::EndFrame()
+{
+	if(mLastBlenderShader) {
+		mLastBlenderShader->SetProg(false);
+		mLastBlenderShader = NULL;
+	}
+
+	if(mLastShader) {
+		mLastShader->SetProg(false);
+		mLastShader = NULL;
+	}
+}
+
 void KX_BlenderMaterial::OnExit()
 {
 	if( mShader ) {
-		 //note, the shader here is allocated, per unique material
-		 //and this function is called per face
-		mShader->SetProg(false);
+		//note, the shader here is allocated, per unique material
+		//and this function is called per face
+		if(mShader == mLastShader) {
+			mShader->SetProg(false);
+			mLastShader = NULL;
+		}
+
 		delete mShader;
 		mShader = 0;
 	}
@@ -197,13 +215,19 @@ void KX_BlenderMaterial::setShaderData( bool enable, RAS_IRasterizer *ras)
 	int i;
 	if( !enable || !mShader->Ok() ) {
 		// frame cleanup.
-		mShader->SetProg(false);
+		if(mShader == mLastShader) {
+			mShader->SetProg(false);
+			mLastShader = NULL;
+		}
+
+		ras->SetBlendingMode(TF_SOLID);
 		BL_Texture::DisableAllTextures();
 		return;
 	}
 
 	BL_Texture::DisableAllTextures();
 	mShader->SetProg(true);
+	mLastShader = mShader;
 	
 	BL_Texture::ActivateFirst();
 
@@ -217,9 +241,12 @@ void KX_BlenderMaterial::setShaderData( bool enable, RAS_IRasterizer *ras)
 	}
 
 	if(!mUserDefBlend) {
-		setDefaultBlending();
+		ras->SetBlendingMode(mMaterial->transp);
 	}
 	else {
+		ras->SetBlendingMode(TF_SOLID);
+		ras->SetBlendingMode(-1); // indicates custom mode
+
 		// tested to be valid enums
 		glEnable(GL_BLEND);
 		glBlendFunc(mBlendFunc[0], mBlendFunc[1]);
@@ -234,11 +261,14 @@ void KX_BlenderMaterial::setBlenderShaderData( bool enable, RAS_IRasterizer *ras
 			mLastBlenderShader->SetProg(false);
 			mLastBlenderShader= NULL;
 		}
+
+		ras->SetBlendingMode(TF_SOLID);
 		BL_Texture::DisableAllTextures();
 		return;
 	}
 
 	if(!mBlenderShader->Equals(mLastBlenderShader)) {
+		ras->SetBlendingMode(mMaterial->transp);
 		BL_Texture::DisableAllTextures();
 
 		if(mLastBlenderShader)
@@ -251,17 +281,17 @@ void KX_BlenderMaterial::setBlenderShaderData( bool enable, RAS_IRasterizer *ras
 
 void KX_BlenderMaterial::setTexData( bool enable, RAS_IRasterizer *ras)
 {
-	if(GLEW_ARB_shader_objects && mShader) 
-		mShader->SetProg(false);
-
 	BL_Texture::DisableAllTextures();
-	if( !enable )
+
+	if( !enable ) {
+		ras->SetBlendingMode(TF_SOLID);
 		return;
+	}
 
 	BL_Texture::ActivateFirst();
 
 	if( mMaterial->IdMode == DEFAULT_BLENDER ) {
-		setDefaultBlending();
+		ras->SetBlendingMode(mMaterial->transp);
 		return;
 	}
 
@@ -271,7 +301,7 @@ void KX_BlenderMaterial::setTexData( bool enable, RAS_IRasterizer *ras)
 			mTextures[0].ActivateTexture();
 			mTextures[0].setTexEnv(0, true);
 			mTextures[0].SetMapping(mMaterial->mapping[0].mapping);
-			setDefaultBlending(); 
+			ras->SetBlendingMode(mMaterial->transp);
 		}
 		return;
 	}
@@ -294,9 +324,12 @@ void KX_BlenderMaterial::setTexData( bool enable, RAS_IRasterizer *ras)
 	}
 
 	if(!mUserDefBlend) {
-		setDefaultBlending();
+		ras->SetBlendingMode(mMaterial->transp);
 	}
 	else {
+		ras->SetBlendingMode(TF_SOLID);
+		ras->SetBlendingMode(-1); // indicates custom mode
+
 		glEnable(GL_BLEND);
 		glBlendFunc(mBlendFunc[0], mBlendFunc[1]);
 	}
@@ -356,6 +389,11 @@ KX_BlenderMaterial::ActivateBlenderShaders(
 {
 	KX_BlenderMaterial *tmp = const_cast<KX_BlenderMaterial*>(this);
 
+	if(mLastShader) {
+		mLastShader->SetProg(false);
+		mLastShader= NULL;
+	}
+
 	// reset... 
 	if(tmp->mMaterial->IsShared()) 
 		cachingInfo =0;
@@ -402,6 +440,11 @@ KX_BlenderMaterial::ActivateMat(
 {
 	KX_BlenderMaterial *tmp = const_cast<KX_BlenderMaterial*>(this);
 
+	if(mLastShader) {
+		mLastShader->SetProg(false);
+		mLastShader= NULL;
+	}
+
 	if(mLastBlenderShader) {
 		mLastBlenderShader->SetProg(false);
 		mLastBlenderShader= NULL;
@@ -451,7 +494,10 @@ KX_BlenderMaterial::Activate(
 			return dopass;
 		}
 		else {
-			mShader->SetProg(false);
+			if(mShader == mLastShader) {
+				mShader->SetProg(false);
+				mLastShader = NULL;
+			}
 			mPass = 0;
 			dopass = false;
 			return dopass;
@@ -499,10 +545,22 @@ bool KX_BlenderMaterial::UsesLighting(RAS_IRasterizer *rasty) const
 
 void KX_BlenderMaterial::ActivateMeshSlot(const KX_MeshSlot & ms, RAS_IRasterizer* rasty) const
 {
-	if(mShader && GLEW_ARB_shader_objects)
+	if(mShader && GLEW_ARB_shader_objects) {
 		mShader->Update(ms, rasty);
-	else if(mBlenderShader && GLEW_ARB_shader_objects)
+	}
+	else if(mBlenderShader && GLEW_ARB_shader_objects) {
+		int blendmode;
+
 		mBlenderShader->Update(ms, rasty);
+
+		/* we do blend modes here, because they can change per object
+		 * with the same material due to obcolor */
+		blendmode = mBlenderShader->GetBlendMode();
+		if((blendmode == TF_SOLID || blendmode == TF_ALPHA) && mMaterial->transp != TF_SOLID)
+			blendmode = mMaterial->transp;
+
+		rasty->SetBlendingMode(blendmode);
+	}
 }
 
 void KX_BlenderMaterial::ActivatGLMaterials( RAS_IRasterizer* rasty )const
@@ -582,31 +640,6 @@ void KX_BlenderMaterial::ActivateTexGen(RAS_IRasterizer *ras) const
 		ras->EnableTextures(false);
 }
 
-bool KX_BlenderMaterial::setDefaultBlending()
-{
-	if( mMaterial->transp &TF_ADD) {
-		glEnable(GL_BLEND);
-		glBlendFunc(GL_ONE, GL_ONE);
-		glDisable ( GL_ALPHA_TEST );
-		return true;
-	}
-	
-	if( mMaterial->transp & TF_ALPHA ) {
-		glEnable(GL_BLEND);
-		glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
-		glDisable ( GL_ALPHA_TEST );
-		return true;
-	}
-	
-	if( mMaterial->transp & TF_CLIP ) {
-		glDisable(GL_BLEND); 
-		glEnable ( GL_ALPHA_TEST );
-		glAlphaFunc(GL_GREATER, 0.5f);
-		return false;
-	}
-	return false;
-}
-
 void KX_BlenderMaterial::setTexMatrixData(int i)
 {
 	glMatrixMode(GL_TEXTURE);
@@ -831,12 +864,14 @@ KX_PYMETHODDEF_DOC( KX_BlenderMaterial, getShader , "getShader()")
 void KX_BlenderMaterial::SetBlenderGLSLShader(void)
 {
 	if(!mBlenderShader)
-		mBlenderShader = new BL_BlenderShader(mMaterial->material, m_lightlayer);
+		mBlenderShader = new BL_BlenderShader(mScene, mMaterial->material, m_lightlayer);
 
 	if(!mBlenderShader->Ok()) {
 		delete mBlenderShader;
 		mBlenderShader = 0;
 	}
+	else
+		m_flag |= RAS_BLENDERGLSL;
 }
 
 KX_PYMETHODDEF_DOC( KX_BlenderMaterial, getMaterialIndex, "getMaterialIndex()")