TexFace to Material Settings big patch

Summary:
========
The idea here is to move the texface options into the material panel.
For images with the change please visit:
http://code.blender.org/index.php/2011/09/bge-material-texface-changes

1 - Some of the legacy problems 2.49 and 2.5x has with the texface system:
==========================================================================
1.1) Shadow, Bilboard and Halo are mutual exclusive (in the code), yet you can
select a face to be more than one mode.
1.2) Sort only works for blend Alpha yet it's an option regardless of the
Transparency Blend you pick.
1.3) Shared doesn't affect anything in BGE.
1.4) ObColor only works for Text objects (old bitmap texts) when using Texture
Face Materials. (not address yet, I so far ignored obcolor)

2 - Notes:
============
2.1) Now "Use Face Textures" in material Option panel will work in Multitexture
even if there is no texture channel.

2.2) In FaceTexture mode it will use TexFace all the time, even if you don't
check the "Use Texture Face" option in the UI. It's a matter of decision, since
the code for either way is there. I decided by the solution that makes the
creation of a material fast - in this mode the user doesn't need to mess with
textures or this "Use Texture Face" option at all. I'm not strong in my opinion
here. But I think if we don't have this then what is the point of the Texture
Face mode?

2.3) I kept references for tface only when we need the image, UV or the tiling
setting. It should help later when/if we split the Image and UV layers from the
tface struct  (Campbell and Brecht proposal).

3 - Changes in a Nutshell:
==========================
3.1) "Texture Face" panel (in the Mesh/Object Data panel) no longer exists. Those settings are all part of the material properties, visible when Game Render is set.

3.2) "Texture Face" Shading mode (in the Render panel) is now called “Single Texture”, it needs a material for special settings (e.g. Billboard, Alpha Sort, …).

3.3) New options in the Material Panel
* Shadeless option in the Material panel is now supported for all three Shading modes.
* Physics is now toggleable, this is the old Collision option.
* Two Side (on) is now called Back Culling (off).
* Alpha Sort is one of the Alpha options, together (and mutually exclusive) to Alpha Blend, Alpha Clip, Add and Opaque (i.e. solid).
* Shadow, Billboard and Halo are grouped in the “Face Orientation” property.
* "Face Textures" and "Face Textures Alpha" (under Options) can be used for all but GLSL shading mode (to be supported in GLSL eventually).
* The backend in the game engine is still the same as before. The only changes are in the interface and in the way you need to think your materials. The bottomline is: It’s no longer possible to share materials between faces that do not share the same game properties.

4 - Acknowledgment:
==================
Mike Pan for the design discussions, and testing along the whole development process.
Vitor Balbio for the first hands-on code with the interface changes. That helped me a lot to push me into work on that.
Benoit Bolsee and Brecht van Lommel for patch review (* no one reviewed the whole patch, or the latest iteractions, so I still hold liability for any problems).
Blender artists that gave feedback and helped testing the patch.

Patch review and original documentation can be found here:
http://wiki.blender.org/index.php/User:Dfelinto/TexFace
http://codereview.appspot.com/4289041/

4 files changed, 48 insertions, 45 deletions

diff --git a/source/blender/gpu/GPU_draw.h b/source/blender/gpu/GPU_draw.h
index d75b8db2c4e..55c4ff85a57 100644
--- a/source/blender/gpu/GPU_draw.h
+++ b/source/blender/gpu/GPU_draw.h
@@ -80,15 +80,15 @@ void GPU_end_object_materials(void);
 int GPU_enable_material(int nr, void *attribs);
 void GPU_disable_material(void);
 
-void GPU_set_material_blend_mode(int blendmode);
-int GPU_get_material_blend_mode(void);
+void GPU_set_material_alpha_blend(int alphablend);
+int GPU_get_material_alpha_blend(void);
 
 /* TexFace drawing
  * - this is mutually exclusive with material drawing, a mesh should
  *   be drawn using one or the other
  * - passing NULL clears the state again */
 
-int GPU_set_tpage(struct MTFace *tface, int mipmap);
+int GPU_set_tpage(struct MTFace *tface, int mipmap, int transp);
 
 /* Lights
  * - returns how many lights were enabled
diff --git a/source/blender/gpu/GPU_material.h b/source/blender/gpu/GPU_material.h
index 95a08e6d5b3..29ad9c91374 100644
--- a/source/blender/gpu/GPU_material.h
+++ b/source/blender/gpu/GPU_material.h
@@ -94,7 +94,8 @@ typedef enum GPUBlendMode {
 	GPU_BLEND_SOLID = 0,
 	GPU_BLEND_ADD = 1,
 	GPU_BLEND_ALPHA = 2,
-	GPU_BLEND_CLIP = 4
+	GPU_BLEND_CLIP = 4,
+	GPU_BLEND_ALPHA_SORT = 8
 } GPUBlendMode;
 
 typedef struct GPUNodeStack {
@@ -121,7 +122,7 @@ int GPU_stack_link(GPUMaterial *mat, const char *name, GPUNodeStack *in, GPUNode
 
 void GPU_material_output_link(GPUMaterial *material, GPUNodeLink *link);
 void GPU_material_enable_alpha(GPUMaterial *material);
-GPUBlendMode GPU_material_blend_mode(GPUMaterial *material, float obcol[4]);
+GPUBlendMode GPU_material_alpha_blend(GPUMaterial *material, float obcol[4]);
 
 /* High level functions to create and use GPU materials */
 
diff --git a/source/blender/gpu/intern/gpu_draw.c b/source/blender/gpu/intern/gpu_draw.c
index 7af5ef6ea14..4f79d577ae5 100644
--- a/source/blender/gpu/intern/gpu_draw.c
+++ b/source/blender/gpu/intern/gpu_draw.c
@@ -95,7 +95,7 @@ void GPU_render_text(MTFace *tface, int mode,
 	const char *textstr, int textlen, unsigned int *col,
 	float *v1, float *v2, float *v3, float *v4, int glattrib)
 {
-	if ((mode & TF_BMFONT) && (textlen>0) && tface->tpage) {
+	if ((mode & GEMAT_TEXT) && (textlen>0) && tface->tpage) {
 		Image* ima = (Image*)tface->tpage;
 		int index, character;
 		float centerx, centery, sizex, sizey, transx, transy, movex, movey, advance;
@@ -245,7 +245,7 @@ static struct GPUTextureState {
 
 	int domipmap, linearmipmap;
 
-	int alphamode;
+	int alphablend;
 	float anisotropic;
 	MTFace *lasttface;
 } GTS = {0, 0, 0, 0, 0, 0, 0, 0, NULL, NULL, 1, 0, -1, 1.f, NULL};
@@ -352,7 +352,7 @@ static void gpu_clear_tpage(void)
 	GTS.curtilemode= 0;
 	GTS.curtileXRep=0;
 	GTS.curtileYRep=0;
-	GTS.alphamode= -1;
+	GTS.alphablend= -1;
 	
 	glDisable(GL_BLEND);
 	glDisable(GL_TEXTURE_2D);
@@ -361,19 +361,19 @@ static void gpu_clear_tpage(void)
 	glDisable(GL_ALPHA_TEST);
 }
 
-static void gpu_set_blend_mode(GPUBlendMode blendmode)
+static void gpu_set_alpha_blend(GPUBlendMode alphablend)
 {
-	if(blendmode == GPU_BLEND_SOLID) {
+	if(alphablend == GPU_BLEND_SOLID) {
 		glDisable(GL_BLEND);
 		glDisable(GL_ALPHA_TEST);
 		glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 	}
-	else if(blendmode==GPU_BLEND_ADD) {
+	else if(alphablend==GPU_BLEND_ADD) {
 		glEnable(GL_BLEND);
 		glBlendFunc(GL_ONE, GL_ONE);
 		glDisable(GL_ALPHA_TEST);
 	}
-	else if(blendmode==GPU_BLEND_ALPHA) {
+	else if(ELEM(alphablend, GPU_BLEND_ALPHA, GPU_BLEND_ALPHA_SORT)) {
 		glEnable(GL_BLEND);
 		glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 		
@@ -389,21 +389,21 @@ static void gpu_set_blend_mode(GPUBlendMode blendmode)
 			glAlphaFunc(GL_GREATER, U.glalphaclip);
 		}
 	}
-	else if(blendmode==GPU_BLEND_CLIP) {
+	else if(alphablend==GPU_BLEND_CLIP) {
 		glDisable(GL_BLEND); 
 		glEnable(GL_ALPHA_TEST);
 		glAlphaFunc(GL_GREATER, 0.5f);
 	}
 }
 
-static void gpu_verify_alpha_mode(MTFace *tface)
+static void gpu_verify_alpha_blend(int alphablend)
 {
 	/* verify alpha blending modes */
-	if(GTS.alphamode == tface->transp)
+	if(GTS.alphablend == alphablend)
 		return;
 
-	gpu_set_blend_mode(tface->transp);
-	GTS.alphamode= tface->transp;
+	gpu_set_alpha_blend(alphablend);
+	GTS.alphablend= alphablend;
 }
 
 static void gpu_verify_reflection(Image *ima)
@@ -608,7 +608,7 @@ static void gpu_verify_repeat(Image *ima)
 		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 }
 
-int GPU_set_tpage(MTFace *tface, int mipmap)
+int GPU_set_tpage(MTFace *tface, int mipmap, int alphablend)
 {
 	Image *ima;
 	
@@ -621,7 +621,7 @@ int GPU_set_tpage(MTFace *tface, int mipmap)
 	ima= tface->tpage;
 	GTS.lasttface= tface;
 
-	gpu_verify_alpha_mode(tface);
+	gpu_verify_alpha_blend(alphablend);
 	gpu_verify_reflection(ima);
 
 	if(GPU_verify_image(ima, NULL, tface->tile, 1, mipmap)) {
@@ -945,12 +945,12 @@ static struct GPUMaterialState {
 	float (*gviewmat)[4];
 	float (*gviewinv)[4];
 
-	GPUBlendMode *blendmode;
-	GPUBlendMode blendmode_fixed[FIXEDMAT];
+	GPUBlendMode *alphablend;
+	GPUBlendMode alphablend_fixed[FIXEDMAT];
 	int alphapass;
 
 	int lastmatnr, lastretval;
-	GPUBlendMode lastblendmode;
+	GPUBlendMode lastalphablend;
 } GMS = {NULL};
 
 /* fixed function material, alpha handed by caller */
@@ -1000,7 +1000,7 @@ void GPU_begin_object_materials(View3D *v3d, RegionView3D *rv3d, Scene *scene, O
 {
 	Material *ma;
 	GPUMaterial *gpumat;
-	GPUBlendMode blendmode;
+	GPUBlendMode alphablend;
 	int a;
 	int gamma = scene->r.color_mgt_flag & R_COLOR_MANAGEMENT;
 	
@@ -1008,7 +1008,7 @@ void GPU_begin_object_materials(View3D *v3d, RegionView3D *rv3d, Scene *scene, O
 	memset(&GMS, 0, sizeof(GMS));
 	GMS.lastmatnr = -1;
 	GMS.lastretval = -1;
-	GMS.lastblendmode = GPU_BLEND_SOLID;
+	GMS.lastalphablend = GPU_BLEND_SOLID;
 
 	GMS.gob = ob;
 	GMS.gscene = scene;
@@ -1024,12 +1024,12 @@ void GPU_begin_object_materials(View3D *v3d, RegionView3D *rv3d, Scene *scene, O
 	if(GMS.totmat > FIXEDMAT) {
 		GMS.matbuf= MEM_callocN(sizeof(GPUMaterialFixed)*GMS.totmat, "GMS.matbuf");
 		GMS.gmatbuf= MEM_callocN(sizeof(*GMS.gmatbuf)*GMS.totmat, "GMS.matbuf");
-		GMS.blendmode= MEM_callocN(sizeof(*GMS.blendmode)*GMS.totmat, "GMS.matbuf");
+		GMS.alphablend= MEM_callocN(sizeof(*GMS.alphablend)*GMS.totmat, "GMS.matbuf");
 	}
 	else {
 		GMS.matbuf= GMS.matbuf_fixed;
 		GMS.gmatbuf= GMS.gmatbuf_fixed;
-		GMS.blendmode= GMS.blendmode_fixed;
+		GMS.alphablend= GMS.alphablend_fixed;
 	}
 
 	/* no materials assigned? */
@@ -1044,7 +1044,7 @@ void GPU_begin_object_materials(View3D *v3d, RegionView3D *rv3d, Scene *scene, O
 			GPU_material_from_blender(GMS.gscene, &defmaterial);
 		}
 
-		GMS.blendmode[0]= GPU_BLEND_SOLID;
+		GMS.alphablend[0]= GPU_BLEND_SOLID;
 	}
 	
 	/* setup materials */
@@ -1060,13 +1060,13 @@ void GPU_begin_object_materials(View3D *v3d, RegionView3D *rv3d, Scene *scene, O
 		if(gpumat) {
 			/* do glsl only if creating it succeed, else fallback */
 			GMS.gmatbuf[a]= ma;
-			blendmode = GPU_material_blend_mode(gpumat, ob->col);
+			alphablend = GPU_material_alpha_blend(gpumat, ob->col);
 		}
 		else {
 			/* fixed function opengl materials */
 			gpu_material_to_fixed(&GMS.matbuf[a], ma, gamma, ob);
 
-			blendmode = (ma->alpha == 1.0f)? GPU_BLEND_SOLID: GPU_BLEND_ALPHA;
+			alphablend = (ma->alpha == 1.0f)? GPU_BLEND_SOLID: GPU_BLEND_ALPHA;
 			if(do_alpha_pass && GMS.alphapass)
 				GMS.matbuf[a].diff[3]= ma->alpha;
 			else
@@ -1076,8 +1076,8 @@ void GPU_begin_object_materials(View3D *v3d, RegionView3D *rv3d, Scene *scene, O
 		/* setting do_alpha_pass = 1 indicates this object needs to be
 		 * drawn in a second alpha pass for improved blending */
 		if(do_alpha_pass) {
-			GMS.blendmode[a]= blendmode;
-			if(ELEM(blendmode, GPU_BLEND_ALPHA, GPU_BLEND_ADD) && !GMS.alphapass)
+			GMS.alphablend[a]= alphablend;
+			if(ELEM3(alphablend, GPU_BLEND_ALPHA, GPU_BLEND_ADD, GPU_BLEND_ALPHA_SORT) && !GMS.alphapass)
 				*do_alpha_pass= 1;
 		}
 	}
@@ -1090,7 +1090,7 @@ int GPU_enable_material(int nr, void *attribs)
 {
 	GPUVertexAttribs *gattribs = attribs;
 	GPUMaterial *gpumat;
-	GPUBlendMode blendmode;
+	GPUBlendMode alphablend;
 
 	/* no GPU_begin_object_materials, use default material */
 	if(!GMS.matbuf) {
@@ -1131,7 +1131,7 @@ int GPU_enable_material(int nr, void *attribs)
 
 	/* draw materials with alpha in alpha pass */
 	GMS.lastmatnr = nr;
-	GMS.lastretval = ELEM(GMS.blendmode[nr], GPU_BLEND_SOLID, GPU_BLEND_CLIP);
+	GMS.lastretval = ELEM(GMS.alphablend[nr], GPU_BLEND_SOLID, GPU_BLEND_CLIP);
 	if(GMS.alphapass)
 		GMS.lastretval = !GMS.lastretval;
 
@@ -1145,6 +1145,7 @@ int GPU_enable_material(int nr, void *attribs)
 			GPU_material_bind(gpumat, GMS.gob->lay, GMS.glay, 1.0, !(GMS.gob->mode & OB_MODE_TEXTURE_PAINT));
 			GPU_material_bind_uniforms(gpumat, GMS.gob->obmat, GMS.gviewmat, GMS.gviewinv, GMS.gob->col);
 			GMS.gboundmat= mat;
+			alphablend= mat->game.alpha_blend;
 
 			if(GMS.alphapass) glDepthMask(1);
 		}
@@ -1153,28 +1154,29 @@ int GPU_enable_material(int nr, void *attribs)
 			glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, GMS.matbuf[nr].diff);
 			glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, GMS.matbuf[nr].spec);
 			glMateriali(GL_FRONT_AND_BACK, GL_SHININESS, GMS.matbuf[nr].hard);
+			alphablend= GPU_BLEND_SOLID;
 		}
 
 		/* set (alpha) blending mode */
-		blendmode = (GMS.alphapass)? GPU_BLEND_ALPHA: GPU_BLEND_SOLID;
-		GPU_set_material_blend_mode(blendmode);
+		if(!GMS.alphapass) alphablend= GPU_BLEND_SOLID;
+		GPU_set_material_alpha_blend(alphablend);
 	}
 
 	return GMS.lastretval;
 }
 
-void GPU_set_material_blend_mode(int blendmode)
+void GPU_set_material_alpha_blend(int alphablend)
 {
-	if(GMS.lastblendmode == blendmode)
+	if(GMS.lastalphablend == alphablend)
 		return;
 	
-	gpu_set_blend_mode(blendmode);
-	GMS.lastblendmode = blendmode;
+	gpu_set_alpha_blend(alphablend);
+	GMS.lastalphablend = alphablend;
 }
 
-int GPU_get_material_blend_mode(void)
+int GPU_get_material_alpha_blend(void)
 {
-	return GMS.lastblendmode;
+	return GMS.lastalphablend;
 }
 
 void GPU_disable_material(void)
@@ -1188,7 +1190,7 @@ void GPU_disable_material(void)
 		GMS.gboundmat= NULL;
 	}
 
-	GPU_set_material_blend_mode(GPU_BLEND_SOLID);
+	GPU_set_material_alpha_blend(GPU_BLEND_SOLID);
 }
 
 void GPU_end_object_materials(void)
@@ -1198,12 +1200,12 @@ void GPU_end_object_materials(void)
 	if(GMS.matbuf && GMS.matbuf != GMS.matbuf_fixed) {
 		MEM_freeN(GMS.matbuf);
 		MEM_freeN(GMS.gmatbuf);
-		MEM_freeN(GMS.blendmode);
+		MEM_freeN(GMS.alphablend);
 	}
 
 	GMS.matbuf= NULL;
 	GMS.gmatbuf= NULL;
-	GMS.blendmode= NULL;
+	GMS.alphablend= NULL;
 
 	/* resetting the texture matrix after the glScale needed for tiled textures */
 	if(GTS.tilemode)
diff --git a/source/blender/gpu/intern/gpu_material.c b/source/blender/gpu/intern/gpu_material.c
index 9aa453af4d6..40186c5a187 100644
--- a/source/blender/gpu/intern/gpu_material.c
+++ b/source/blender/gpu/intern/gpu_material.c
@@ -358,7 +358,7 @@ void GPU_material_enable_alpha(GPUMaterial *material)
 	material->alpha= 1;
 }
 
-GPUBlendMode GPU_material_blend_mode(GPUMaterial *material, float obcol[4])
+GPUBlendMode GPU_material_alpha_blend(GPUMaterial *material, float obcol[4])
 {
 	if(material->alpha || (material->obcolalpha && obcol[3] < 1.0f))
 		return GPU_BLEND_ALPHA;