Some refactoring of the draw code path

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

diff --git a/source/batch.cpp b/source/batch.cpp
index 7100653ea17800cf9ebd6364e6d5fba41443948b..a59fad99f03b988309ef60042324df71ebf3c6ab 100644 (file)
--- a/source/batch.cpp
+++ b/source/batch.cpp
@@ -1,4 +1,6 @@
 #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>
 #include <msp/gl/extensions/nv_primitive_restart.h>
 #include "batch.h"
 #include "bindable.h"
@@ -58,11 +60,7 @@ Batch::Batch(PrimitiveType t):
        min_index(0),
        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()
 {
@@ -105,10 +103,10 @@ 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)
@@ -116,31 +114,40 @@ void Batch::append(const vector<unsigned> &ind)
 
        update_offset();
        dirty = true;
+
+       return *this;
 }
 
 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)
-               return NV_primitive_restart;
+       else if(prim_type==LINE_STRIP || prim_type==LINE_LOOP || prim_type==TRIANGLE_FAN)
+               return MSP_primitive_restart || NV_primitive_restart;
        else
                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 || prim_type==POLYGON)
-               static Require _req(NV_primitive_restart);
+       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)
                ;
-       else if(NV_primitive_restart)
+       else if(MSP_primitive_restart || NV_primitive_restart)
        {
                restart = true;
                if(data_type==UNSIGNED_SHORT)
@@ -171,6 +178,8 @@ void Batch::append(const Batch &other)
 
        update_offset();
        dirty = true;
+
+       return *this;
 }
 
 void Batch::append_index(unsigned i)
@@ -196,11 +205,6 @@ 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)
@@ -221,6 +225,17 @@ 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);
+}
+
+const void *Batch::setup_draw() const
 {
        if(restart)
        {
@@ -233,30 +248,48 @@ void Batch::draw() const
                        index = 0xFF;
 
                if(index!=restart_index)
-               {
-                       if(!restart_index)
-                               glEnableClientState(GL_PRIMITIVE_RESTART_NV);
-                       glPrimitiveRestartIndexNV(index);
-                       restart_index = index;
-               }
+                       set_restart_index(index);
        }
        else if(restart_index && restart_index<=max_index)
-       {
-               glDisableClientState(GL_PRIMITIVE_RESTART_NV);
-               restart_index = 0;
-       }
+               set_restart_index(0);
 
-       Buffer *ibuf = get_buffer();
-       BindRestore _bind_ibuf(ibuf, ELEMENT_ARRAY_BUFFER);
-       if(ibuf)
+       if(get_buffer())
        {
                if(dirty)
                        update_buffer();
 
-               glDrawRangeElements(prim_type, min_index, max_index, size(), data_type, reinterpret_cast<void *>(get_offset()));
+               return reinterpret_cast<const void *>(get_offset());
+       }
+       else
+               return &data[0];
+}
+
+void Batch::set_restart_index(unsigned index)
+{
+       if(MSP_primitive_restart)
+       {
+               if(index>0)
+               {
+                       if(!restart_index)
+                               glEnable(GL_PRIMITIVE_RESTART);
+                       glPrimitiveRestartIndex(index);
+               }
+               else
+                       glDisable(GL_PRIMITIVE_RESTART);
        }
        else
-               glDrawRangeElements(prim_type, min_index, max_index, size(), data_type, &data[0]);
+       {
+               if(index>0)
+               {
+                       if(!restart_index)
+                               glEnableClientState(GL_PRIMITIVE_RESTART_NV);
+                       glPrimitiveRestartIndexNV(index);
+               }
+               else
+                       glDisableClientState(GL_PRIMITIVE_RESTART_NV);
+       }
+
+       restart_index = index;
 }