Initial support for instanced rendering

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

diff --git a/source/batch.cpp b/source/batch.cpp
index 3d7dfc720ad901d40832e77510d3159339910e29..af1d243e6cba1551e6be65255a55e69a4e7029cf 100644 (file)
--- a/source/batch.cpp
+++ b/source/batch.cpp
@@ -1,3 +1,4 @@
+#include <msp/gl/extensions/arb_draw_instanced.h>
 #include <msp/gl/extensions/ext_draw_range_elements.h>
 #include <msp/gl/extensions/msp_legacy_features.h>
 #include <msp/gl/extensions/msp_primitive_restart.h>
@@ -60,12 +61,7 @@ Batch::Batch(PrimitiveType t):
        min_index(0),
        max_index(0),
        restart(false)
-{
-       /* Make sure we have glEnable/DisableClientState to go with
-       NV_primitive_restart */
-       if(!MSP_primitive_restart && NV_primitive_restart)
-               (bool)MSP_legacy_features;
-}
+{ }
 
 Batch::~Batch()
 {
@@ -108,10 +104,10 @@ Batch &Batch::append(unsigned i)
        return *this;
 }
 
-void Batch::append(const vector<unsigned> &ind)
+Batch &Batch::append(const vector<unsigned> &ind)
 {
        if(ind.empty())
-               return;
+               return *this;
 
        data.reserve(data.size()+ind.size()*get_index_size());
        for(vector<unsigned>::const_iterator i=ind.begin(); i!=ind.end(); ++i)
@@ -119,6 +115,8 @@ void Batch::append(const vector<unsigned> &ind)
 
        update_offset();
        dirty = true;
+
+       return *this;
 }
 
 bool Batch::can_append(PrimitiveType other_type)
@@ -131,18 +129,22 @@ bool Batch::can_append(PrimitiveType other_type)
                return true;
 }
 
-void Batch::append(const Batch &other)
+Batch &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)
        {
                if(!MSP_primitive_restart)
+               {
                        static Require _req(NV_primitive_restart);
+                       // Make sure we have glEnable/DisableClientState as well
+                       static Require _req2(MSP_legacy_features);
+               }
        }
 
        if(other.data.empty())
-               return;
+               return *this;
 
        if(prim_type==POINTS || prim_type==LINES || prim_type==TRIANGLES || prim_type==QUADS)
                ;
@@ -177,6 +179,8 @@ void Batch::append(const Batch &other)
 
        update_offset();
        dirty = true;
+
+       return *this;
 }
 
 void Batch::append_index(unsigned i)
@@ -222,6 +226,27 @@ unsigned Batch::get_index(unsigned i) const
 }
 
 void Batch::draw() const
+{
+       BindRestore _bind_ibuf(get_buffer(), ELEMENT_ARRAY_BUFFER);
+       const void *data_ptr = setup_draw();
+
+       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);
+}
+
+void Batch::draw_instanced(unsigned count) const
+{
+       static Require req(ARB_draw_instanced);
+
+       BindRestore _bind_ibuf(get_buffer(), ELEMENT_ARRAY_BUFFER);
+       const void *data_ptr = setup_draw();
+
+       glDrawElementsInstanced(prim_type, size(), data_type, data_ptr, count);
+}
+
+const void *Batch::setup_draw() const
 {
        if(restart)
        {
@@ -239,23 +264,15 @@ void Batch::draw() const
        else if(restart_index && restart_index<=max_index)
                set_restart_index(0);
 
-       Buffer *ibuf = get_buffer();
-       const void *data_ptr;
-       BindRestore _bind_ibuf(ibuf, ELEMENT_ARRAY_BUFFER);
-       if(ibuf)
+       if(get_buffer())
        {
                if(dirty)
                        update_buffer();
 
-               data_ptr = reinterpret_cast<const void *>(get_offset());
+               return reinterpret_cast<const void *>(get_offset());
        }
        else
-               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);
+               return &data[0];
 }
 
 void Batch::set_restart_index(unsigned index)