From 169a16b63ee5585ab1d70402c7de23dca8b84db7 Mon Sep 17 00:00:00 2001
From: Sam Hocevar <sam@hocevar.net>
Date: Sun, 15 Apr 2012 21:20:05 +0000
Subject: [PATCH] gpu: move the platform-specific triangle drawing call to the
 VertexDeclaration class, so that the calling code does not need to know what
 the backend is.

---
 src/gpu/vertexbuffer.cpp | 31 ++++++++++++++++++++----
 src/gpu/vertexbuffer.h   | 13 ++++++++++
 test/tutorial/tut01.cpp  | 52 ++--------------------------------------
 3 files changed, 41 insertions(+), 55 deletions(-)

diff --git a/src/gpu/vertexbuffer.cpp b/src/gpu/vertexbuffer.cpp
index e8c586c2..79a4f88f 100644
--- a/src/gpu/vertexbuffer.cpp
+++ b/src/gpu/vertexbuffer.cpp
@@ -118,15 +118,39 @@ void VertexDeclaration::Bind()
 #endif
 }
 
+void VertexDeclaration::DrawElements(MeshPrimitive type, int skip, int count)
+{
+#if defined _XBOX || defined USE_D3D9
+    g_d3ddevice->SetRenderState(D3DRS_CULLMODE, D3DCULL_CW);
+    switch (type)
+    {
+    case MeshPrimitive::Triangles:
+        g_d3ddevice->DrawPrimitive(D3DPT_TRIANGLELIST, skip, count);
+        break;
+    }
+#else
+    switch (type)
+    {
+    case MeshPrimitive::Triangles:
+        glDrawArrays(GL_TRIANGLES, skip * 3, count * 3);
+        break;
+    }
+#endif
+}
+
 void VertexDeclaration::Unbind()
 {
 #if defined _XBOX || defined USE_D3D9
     /* FIXME: Nothing to do? */
 #else
-    /* FIXME: we need to record what happens */
+    /* FIXME: we need to unbind what we bound */
     //glDisableVertexAttribArray(m_attrib);
     /* FIXME: only useful for VAOs */
     //glBindBuffer(GL_ARRAY_BUFFER, 0);
+    /* Or: */
+    //glDisableVertexAttribArray(m_attrib);
+    /* Or even: */
+    //glDisableClientState(GL_VERTEX_ARRAY);
 #endif
 }
 
@@ -185,15 +209,12 @@ void VertexDeclaration::SetStream(VertexBuffer *vb, ShaderAttrib attr1,
         /* We need to parse the whole vertex declaration to retrieve
          * the information. It sucks. */
 
-        int attr_index = 0, usage_index = 0, stream = -1;
+        int attr_index = 0, usage_index = 0;
         /* First, find the stream index */
         for (; attr_index < m_count; attr_index++)
             if (m_streams[attr_index].usage == usage)
                 if (usage_index++ == index)
-                {
-                    stream = m_streams[attr_index].index;
                     break;
-                }
 
         /* Now compute the stride and offset up to this stream index */
         int stride = 0, offset = 0;
diff --git a/src/gpu/vertexbuffer.h b/src/gpu/vertexbuffer.h
index 2545c157..1ea63f42 100644
--- a/src/gpu/vertexbuffer.h
+++ b/src/gpu/vertexbuffer.h
@@ -61,6 +61,18 @@ struct VertexUsage
     inline operator Value() { return m_value; }
 };
 
+struct MeshPrimitive
+{
+    enum Value
+    {
+        Triangles,
+    }
+    m_value;
+
+    inline MeshPrimitive(Value v) { m_value = v; }
+    inline operator Value() { return m_value; }
+};
+
 class VertexStreamBase
 {
     friend class VertexDeclaration;
@@ -164,6 +176,7 @@ public:
     ~VertexDeclaration();
 
     void Bind();
+    void DrawElements(MeshPrimitive type, int skip, int count);
     void Unbind();
     void SetStream(VertexBuffer *vb, ShaderAttrib attr1,
                                      ShaderAttrib attr2 = ShaderAttrib(),
diff --git a/test/tutorial/tut01.cpp b/test/tutorial/tut01.cpp
index 4d5a4145..59717f42 100644
--- a/test/tutorial/tut01.cpp
+++ b/test/tutorial/tut01.cpp
@@ -13,18 +13,11 @@
 #endif
 
 #include "core.h"
-#include "lolgl.h"
 #include "loldebug.h"
 
 using namespace std;
 using namespace lol;
 
-#if defined _WIN32 && defined USE_D3D9
-#   define FAR
-#   define NEAR
-#   include <d3d9.h>
-#endif
-
 #if USE_SDL && defined __APPLE__
 #   include <SDL_main.h>
 #endif
@@ -38,12 +31,6 @@ using namespace lol;
 #   include <direct.h>
 #endif
 
-#if defined USE_D3D9
-extern IDirect3DDevice9 *g_d3ddevice;
-#elif defined _XBOX
-extern D3DDevice *g_d3ddevice;
-#endif
-
 class Triangle : public WorldEntity
 {
 public:
@@ -61,21 +48,6 @@ public:
 
         if (!m_ready)
         {
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
             m_shader = Shader::Create(
 #if !defined __CELLOS_LV2__ && !defined _XBOX && !defined USE_D3D9
                 "#version 120\n"
@@ -116,36 +88,16 @@ public:
         m_shader->Bind();
         m_vdecl->Bind();
         m_vdecl->SetStream(m_vbo, m_coord);
-#if defined _XBOX || defined USE_D3D9
-        g_d3ddevice->SetRenderState(D3DRS_CULLMODE, D3DCULL_CW);
-#endif
-
-#if defined _XBOX || defined USE_D3D9
-        g_d3ddevice->DrawPrimitive(D3DPT_TRIANGLELIST, 0, 1);
-#else
-        glDrawArrays(GL_TRIANGLES, 0, 3);
-#endif
-
+        m_vdecl->DrawElements(MeshPrimitive::Triangles, 0, 1);
         m_vdecl->Unbind();
-#if defined _XBOX || defined USE_D3D9
-        /* FIXME: do we need to unset anything here? */
-#elif !defined __CELLOS_LV2__ && !defined __ANDROID__ && !defined __APPLE__
-        //glDisableVertexAttribArray(m_attrib);
-        //glBindBuffer(GL_ARRAY_BUFFER, 0);
-#elif !defined __CELLOS_LV2__ && !defined __ANDROID__ && !defined __APPLE__
-        /* Never used for now */
-        glDisableVertexAttribArray(m_attrib);
-#else
-        glDisableClientState(GL_VERTEX_ARRAY);
-#endif
     }
 
 private:
     vec2 m_vertices[3];
     Shader *m_shader;
+    ShaderAttrib m_coord;
     VertexDeclaration *m_vdecl;
     VertexBuffer *m_vbo;
-    ShaderAttrib m_coord;
     bool m_ready;
 };