Add a helper function for making indexed vertex components

This puts the logic for checking the allowable index ranges in one place.

The base for an indexed component must now be one with a zero index.  It
didn't make much sense to add an index to an already indexed component.

VertexFormat::offset no longer takes an index, since the helper function
can be used.

diff --git a/source/vertexformat.cpp b/source/vertexformat.cpp
index 0a26d94268847b94d443bcf6e9d47192936d1722..ea5845c5fc10f56cca9b217a6db5c405e9b0028c 100644 (file)
--- a/source/vertexformat.cpp
+++ b/source/vertexformat.cpp
@@ -77,9 +77,7 @@ VertexFormat VertexFormat::operator,(unsigned i) const
                throw invalid_operation("VertexFormat::operator,");
        VertexFormat r = *this;
        unsigned char *c = r.data+r.data[0];
-       if((*c<TEXCOORD1 && i>0) || (*c<ATTRIB1 && i>=8) || i>=53)
-               throw invalid_argument("VertexFormat::operator,");
-       *c += i*4;
+       *c = make_indexed_component(static_cast<VertexComponent>(*c), i);
 
        return r;
 }
@@ -92,12 +90,9 @@ unsigned VertexFormat::stride() const
        return s;
 }
 
-int VertexFormat::offset(VertexComponent comp, unsigned index) const
+int VertexFormat::offset(VertexComponent comp) const
 {
-       if((comp<TEXCOORD1 && index>0) || (comp<ATTRIB1 && index>=8) || index>=53)
-               throw out_of_range("VertexFormat::offset");
-
-       unsigned type = get_component_type(comp)+index;
+       unsigned type = get_component_type(comp);
        unsigned size = get_component_size(comp);
        unsigned offs = 0;
        for(const unsigned char *i=begin(); i!=end(); ++i)
@@ -116,6 +111,23 @@ int VertexFormat::offset(VertexComponent comp, unsigned index) const
        return -1;
 }
 
+VertexComponent make_indexed_component(VertexComponent comp, unsigned index)
+{
+       if(comp>=TEXCOORD1 && comp<=TEXCOORD4)
+       {
+               if(index>=4)
+                       throw out_of_range("make_indexed_component");
+       }
+       else if(comp>=ATTRIB1 && comp<=ATTRIB4)
+       {
+               if(index>=53)
+                       throw out_of_range("make_indexed_component");
+       }
+       else
+               throw invalid_argument("make_indexed_component");
+       return static_cast<VertexComponent>(comp+index*4);
+}
+
 void operator>>(const LexicalConverter &conv, VertexComponent &c)
 {
        const string &str = conv.get();

diff --git a/source/vertexformat.h b/source/vertexformat.h
index fb47484b35940b7e873b6d2586d333df0edda802..018d21f00e5176a322b8cbe262da5d355b762bb1 100644 (file)
--- a/source/vertexformat.h
+++ b/source/vertexformat.h
@@ -44,7 +44,7 @@ public:
        const unsigned char *begin() const { return data ? data+1 : 0; }
        const unsigned char *end() const { return data ? data+1+data[0] : 0; }
        unsigned stride() const;
-       int offset(VertexComponent, unsigned = 0) const;
+       int offset(VertexComponent) const;
 };
 
 inline VertexFormat operator,(VertexComponent c1, VertexComponent c2)
@@ -53,6 +53,8 @@ inline VertexFormat operator,(VertexComponent c1, VertexComponent c2)
 inline VertexFormat operator,(VertexComponent c, unsigned i)
 { return (VertexFormat(c), i); }
 
+VertexComponent make_indexed_component(VertexComponent, unsigned);
+
 inline unsigned get_component_type(unsigned char c)
 { return c>>2; }