Fix GLES 2 after the multiple-texture-rectangle branch merge

The GLES 2 wrapper needs to set up some state before each
draw. Previously this was acheived by wrapping glDrawArrays. Since the
multiple-texture-rectangle branch merge, glDrawElements is used
instead so we also need a wrapper for that.

It was also directly calling glBindTexture. GLES 2 uses a wrapper for
this function so that it can cope with GL_ALPHA format textures. The
format of the current texture needs to be stored as well as the target
and object number for this to work.

clutter/cogl/gles/cogl-context.h

@@ -72,6 +72,7 @@ typedef struct
      can be flushed */
   GLuint               texture_current;
   GLenum               texture_target;
+  GLenum               texture_format;
 
   /* Framebuffer objects */
   GArray              *fbo_handles;

clutter/cogl/gles/cogl-gles2-wrapper.c

@@ -891,8 +891,8 @@ cogl_gles2_do_set_uniform (GLint location, CoglBoxedValue *value)
     }
 }
 
-void
+static void
-cogl_wrap_glDrawArrays (GLenum mode, GLint first, GLsizei count)
+cogl_wrap_prepare_for_draw (void)
 {
   CoglGles2WrapperProgram *program;
 
@@ -999,9 +999,25 @@ cogl_wrap_glDrawArrays (GLenum mode, GLint first, GLsizei count)
       w->dirty_custom_uniforms = 0;
     }
 
+}
+
+void
+cogl_wrap_glDrawArrays (GLenum mode, GLint first, GLsizei count)
+{
+  cogl_wrap_prepare_for_draw ();
+
   glDrawArrays (mode, first, count);
 }
 
+void
+cogl_wrap_glDrawElements (GLenum mode, GLsizei count, GLenum type,
+                          const GLvoid *indices)
+{
+  cogl_wrap_prepare_for_draw ();
+
+  glDrawElements (mode, count, type, indices);
+}
+
 void
 cogl_gles2_wrapper_bind_texture (GLenum target, GLuint texture,
 				 GLenum internal_format)

clutter/cogl/gles/cogl-gles2-wrapper.h

@@ -250,7 +250,8 @@ void cogl_wrap_glFogx (GLenum pname, GLfixed param);
 void cogl_wrap_glFogxv (GLenum pname, const GLfixed *params);
 
 void cogl_wrap_glDrawArrays (GLenum mode, GLint first, GLsizei count);
-
+void cogl_wrap_glDrawElements (GLenum mode, GLsizei count, GLenum type,
+                               const GLvoid *indices);
 void cogl_wrap_glTexParameteri (GLenum target, GLenum pname, GLfloat param);
 
 void cogl_gles2_wrapper_bind_texture (GLenum target, GLuint texture,
@@ -274,6 +275,7 @@ void _cogl_gles2_clear_cache_for_program (CoglHandle program);
 
 #define cogl_wrap_glClearColorx        glClearColorx
 #define cogl_wrap_glDrawArrays         glDrawArrays
+#define cogl_wrap_glDrawElements       glDrawElements
 #define cogl_wrap_glPushMatrix         glPushMatrix
 #define cogl_wrap_glPopMatrix          glPopMatrix
 #define cogl_wrap_glMatrixMode         glMatrixMode

clutter/cogl/gles/cogl-texture.c

@@ -44,6 +44,7 @@
 #define glTexCoordPointer cogl_wrap_glTexCoordPointer
 #define glColorPointer cogl_wrap_glColorPointer
 #define glDrawArrays cogl_wrap_glDrawArrays
+#define glDrawElements cogl_wrap_glDrawElements
 #define glTexParameteri cogl_wrap_glTexParameteri
 
 /*
@@ -2094,7 +2095,9 @@ _cogl_texture_flush_vertices (void)
       GE( glTexCoordPointer (2, GL_FLOAT,
                              sizeof (CoglTextureGLVertex), p->t ) );
 
-      GE( glBindTexture (ctx->texture_target, ctx->texture_current) );
+      GE( cogl_gles2_wrapper_bind_texture (ctx->texture_target,
+                                           ctx->texture_current,
+                                           ctx->texture_format) );
       GE( glDrawElements (GL_TRIANGLES,
                           needed_indices,
                           GL_UNSIGNED_SHORT,
@@ -2284,6 +2287,7 @@ _cogl_texture_quad_sw (CoglTexture *tex,
             _cogl_texture_flush_vertices ();
           ctx->texture_target = tex->gl_target;
           ctx->texture_current = gl_handle;
+          ctx->texture_format = tex->gl_intformat;
 
           _cogl_texture_add_quad_vertices (COGL_FIXED_TO_FLOAT (slice_qx1),
                                            COGL_FIXED_TO_FLOAT (slice_qy1),
@@ -2328,6 +2332,7 @@ _cogl_texture_quad_hw (CoglTexture *tex,
     _cogl_texture_flush_vertices ();
   ctx->texture_target = tex->gl_target;
   ctx->texture_current = gl_handle;
+  ctx->texture_format = tex->gl_intformat;
 
   /* Don't include the waste in the texture coordinates */
   x_span = &g_array_index (tex->slice_x_spans, CoglTexSliceSpan, 0);