Fallback to glDrawElements if EXT_draw_range_elements is unavailable

[libs/gl.git] / source / batch.cpp

diff --git a/source/batch.cpp b/source/batch.cpp
index 09a6a6111314262d57b7607939da42a74ecc3f89..3cb0a6ce8dacd443210e47f57b45291611235420 100644 (file)
--- a/source/batch.cpp
+++ b/source/batch.cpp
@@ -4,6 +4,7 @@
 #include "bindable.h"
 #include "buffer.h"
 #include "error.h"
+#include "mesh.h"
 #include "vertexarray.h"
 
 using namespace std;
@@ -58,9 +59,6 @@ Batch::Batch(PrimitiveType t):
        max_index(0),
        restart(false)
 {
-       /* XXX Should probably provide a fallback to glDrawElements since this class
-       is pretty much required to render anything. */
-       static Require _req(EXT_draw_range_elements);
 }
 
 Batch::~Batch()
@@ -121,7 +119,7 @@ bool Batch::can_append(PrimitiveType other_type)
 {
        if(other_type!=prim_type)
                return false;
-       else if(prim_type==LINE_STRIP || prim_type==LINE_LOOP || prim_type==TRIANGLE_FAN || prim_type==POLYGON)
+       else if(prim_type==LINE_STRIP || prim_type==LINE_LOOP || prim_type==TRIANGLE_FAN)
                return NV_primitive_restart;
        else
                return true;
@@ -131,7 +129,7 @@ void Batch::append(const Batch &other)
 {
        if(other.prim_type!=prim_type)
                throw invalid_argument("Batch::append");
-       if(prim_type==LINE_STRIP || prim_type==LINE_LOOP || prim_type==TRIANGLE_FAN || prim_type==POLYGON)
+       if(prim_type==LINE_STRIP || prim_type==LINE_LOOP || prim_type==TRIANGLE_FAN)
                static Require _req(NV_primitive_restart);
 
        if(other.data.empty())
@@ -195,11 +193,6 @@ void Batch::append_index(unsigned i)
                data.push_back(i);
 }
 
-void Batch::upload_data() const
-{
-       get_buffer()->sub_data(get_offset(), data.size(), &data[0]);
-}
-
 unsigned Batch::get_index_size() const
 {
        if(data_type==UNSIGNED_SHORT)
@@ -245,18 +238,23 @@ void Batch::draw() const
                restart_index = 0;
        }
 
-       if(Buffer *ibuf = get_buffer())
+       Buffer *ibuf = get_buffer();
+       const void *data_ptr;
+       BindRestore _bind_ibuf(ibuf, ELEMENT_ARRAY_BUFFER);
+       if(ibuf)
        {
-               BufferAlias<ELEMENT_ARRAY_BUFFER> alias(*ibuf);
-               Bind bind_ibuf(alias, true);
-
                if(dirty)
                        update_buffer();
 
-               glDrawRangeElements(prim_type, min_index, max_index, size(), data_type, reinterpret_cast<void *>(get_offset()));
+               data_ptr = reinterpret_cast<const void *>(get_offset());
        }
        else
-               glDrawRangeElements(prim_type, min_index, max_index, size(), data_type, &data[0]);
+               data_ptr = &data[0];
+
+       if(EXT_draw_range_elements)
+               glDrawRangeElements(prim_type, min_index, max_index, size(), data_type, data_ptr);
+       else
+               glDrawElements(prim_type, size(), data_type, data_ptr);
 }