From 40c364b04084d11573a9ff9f7be6f1c4cc521f4b Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 2 Sep 2012 17:50:48 +0300
Subject: [PATCH] Rearrange vertex components

The first 16 component types are now reserved for the library.  This
leaves room for adding standard generic attributes, such as TBN vectors.
To make further room, texcoords were limited to four indices.

Generic attributes are limited to 24.  Current implementations seem to
only support 16 (the minimum allowed by the spec), so this is not a huge
problem.  There's also exactly enough room for another set of 24 generic
integer attributes.
---
 source/vertexarray.cpp        | 11 +++++++----
 source/vertexarraybuilder.cpp |  4 +++-
 source/vertexformat.cpp       |  2 +-
 source/vertexformat.h         | 13 ++++++++-----
 4 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/source/vertexarray.cpp b/source/vertexarray.cpp
index 6c037f9f..e91062bb 100644
--- a/source/vertexarray.cpp
+++ b/source/vertexarray.cpp
@@ -32,7 +32,7 @@ void VertexArray::reset(const VertexFormat &f)
 	bool has_gen_attrs = false;
 	for(const unsigned char *c=format.begin(); c!=format.end(); ++c)
 	{
-		if(*c>=TEXCOORD1+4 && *c<ATTRIB1)
+		if(*c>=TEXCOORD1+4 && *c<=TEXCOORD4+12)
 			has_multitex = true;
 		if(*c>=ATTRIB1)
 			has_gen_attrs = true;
@@ -140,7 +140,7 @@ void VertexArray::apply() const
 			if(!en)
 				glEnableClientState(GL_COLOR_ARRAY);
 		}
-		else if(*c>=TEXCOORD1 && *c<=TEXCOORD4+28)
+		else if(*c>=TEXCOORD1 && *c<=TEXCOORD4+12)
 		{
 			t -= get_component_type(TEXCOORD1);
 			if(t>0 || active_tex)
@@ -154,7 +154,8 @@ void VertexArray::apply() const
 		}
 		else
 		{
-			t -= get_component_type(ATTRIB1);
+			if(t>=get_component_type(ATTRIB1))
+				t -= get_component_type(ATTRIB1);
 			glVertexAttribPointer(t, sz, GL_FLOAT, false, bpv, base+offset);
 			if(!en)
 				glEnableVertexAttribArray(t);
@@ -172,7 +173,7 @@ void VertexArray::apply() const
 				glDisableClientState(GL_NORMAL_ARRAY);
 			else if(i==get_component_type(COLOR4_FLOAT))
 				glDisableClientState(GL_COLOR_ARRAY);
-			else if(i>=get_component_type(TEXCOORD1) && i<=get_component_type(TEXCOORD1)+7)
+			else if(i>=get_component_type(TEXCOORD1) && i<=get_component_type(TEXCOORD1)+3)
 			{
 				unsigned j = i-get_component_type(TEXCOORD1);
 				if(j>0 || active_tex)
@@ -180,6 +181,8 @@ void VertexArray::apply() const
 				glDisableClientState(GL_TEXTURE_COORD_ARRAY);
 				active_tex = j;
 			}
+			else if(i<get_component_type(ATTRIB1))
+				glDisableVertexAttribArray(i);
 			else
 				glDisableVertexAttribArray(i-get_component_type(ATTRIB1));
 		}
diff --git a/source/vertexarraybuilder.cpp b/source/vertexarraybuilder.cpp
index a30c6e21..55b2a6a8 100644
--- a/source/vertexarraybuilder.cpp
+++ b/source/vertexarraybuilder.cpp
@@ -42,10 +42,12 @@ void VertexArrayBuilder::vertex_(const Vector4 &ver)
 			const Vector4 *v = 0;
 			if(t==get_component_type(VERTEX3))
 				v = &ver;
-			else if(*c>=TEXCOORD1 && *c<=TEXCOORD4+28)
+			else if(*c>=TEXCOORD1 && *c<=TEXCOORD4+12)
 				v = &texc[t-get_component_type(TEXCOORD1)];
 			else if(*c>=ATTRIB1)
 				v = &attr[t-get_component_type(ATTRIB1)];
+			else
+				v = &attr[t];
 			*ptr++ = v->x;
 			if(sz>=2) *ptr++ = v->y;
 			if(sz>=3) *ptr++ = v->z;
diff --git a/source/vertexformat.cpp b/source/vertexformat.cpp
index ea5845c5..146fc680 100644
--- a/source/vertexformat.cpp
+++ b/source/vertexformat.cpp
@@ -120,7 +120,7 @@ VertexComponent make_indexed_component(VertexComponent comp, unsigned index)
 	}
 	else if(comp>=ATTRIB1 && comp<=ATTRIB4)
 	{
-		if(index>=53)
+		if(index>=24)
 			throw out_of_range("make_indexed_component");
 	}
 	else
diff --git a/source/vertexformat.h b/source/vertexformat.h
index 018d21f0..95e9b2c5 100644
--- a/source/vertexformat.h
+++ b/source/vertexformat.h
@@ -6,20 +6,23 @@
 namespace Msp {
 namespace GL {
 
+/** A single vertex component.  Nvidia drivers have aliasing between the
+fixed-functions and generic vertex attributes, despite the standard not
+allowing it.  We use the same attribute indices here to avoid problems. */
 enum VertexComponent
 {
 	VERTEX2 = 1,
 	VERTEX3,
 	VERTEX4,
-	NORMAL3 = 6,
-	COLOR4_UBYTE = 8,
-	COLOR3_FLOAT = 10,
+	NORMAL3 = 10,
+	COLOR4_UBYTE = 12,
+	COLOR3_FLOAT = 14,
 	COLOR4_FLOAT,
-	TEXCOORD1 = 12,
+	TEXCOORD1 = 32,
 	TEXCOORD2,
 	TEXCOORD3,
 	TEXCOORD4,
-	ATTRIB1 = 44,
+	ATTRIB1 = 64,
 	ATTRIB2,
 	ATTRIB3,
 	ATTRIB4
-- 
2.45.2