* clutter/cogl/gles/cogl-gles2-wrapper.h (CoglGles2Wrapper): Added

uniforms for alpha testing.

	* clutter/cogl/gles/cogl-gles2-wrapper.c
	(cogl_gles2_wrapper_init): Get the uniforms for alpha testing
	settings.
	(cogl_wrap_glEnable, cogl_wrap_glDisable): Enable/disable alpha
	testing.
	(cogl_wrap_glAlphaFunc): Filled in the wrapper.

	* clutter/cogl/gles/cogl-fixed-fragment-shader.glsl: Added alpha
	testing.

	* clutter/cogl/gles/cogl-gles2-wrapper.h:
	* clutter/cogl/gles/cogl-gles2-wrapper.c
	(cogl_wrap_glGetIntegerv): Added a wrapper for glGetIntegerv so
	that it can report zero clip planes.

	* clutter/cogl/gles/cogl.c:
	* clutter/cogl/gles/cogl-texture.c: Use the wrapped version of
	glGetIntegerv

	* clutter/cogl/gles/cogl-primitives.c (_cogl_path_fill_nodes): Use
	_cogl_features_available to check for the stencil buffer instead
	of an #ifdef. The stencil buffer is available in the default
	profile for the GLES 2 simulator.

ChangeLog

@@ -1,3 +1,33 @@
+2008-05-29  Neil Roberts  <neil@o-hand.com>
+
+    	* clutter/cogl/gles/cogl-gles2-wrapper.h (CoglGles2Wrapper): Added
+    	uniforms for alpha testing.
+    
+    	* clutter/cogl/gles/cogl-gles2-wrapper.c
+    	(cogl_gles2_wrapper_init): Get the uniforms for alpha testing
+    	settings.
+    	(cogl_wrap_glEnable, cogl_wrap_glDisable): Enable/disable alpha
+    	testing.
+    	(cogl_wrap_glAlphaFunc): Filled in the wrapper.
+    
+    	* clutter/cogl/gles/cogl-fixed-fragment-shader.glsl: Added alpha
+    	testing.
+
+    	* clutter/cogl/gles/cogl-gles2-wrapper.h:
+    	* clutter/cogl/gles/cogl-gles2-wrapper.c
+    	(cogl_wrap_glGetIntegerv): Added a wrapper for glGetIntegerv so
+    	that it can report zero clip planes.
+    
+    	* clutter/cogl/gles/cogl.c:
+    	* clutter/cogl/gles/cogl-texture.c: Use the wrapped version of
+    	glGetIntegerv
+
+    	* clutter/cogl/gles/cogl-primitives.c (_cogl_path_fill_nodes): Use
+    	_cogl_features_available to check for the stencil buffer instead
+    	of an #ifdef. The stencil buffer is available in the default
+    	profile for the GLES 2 simulator.
+
+
 2008-05-29  Emmanuele Bassi  <ebassi@openedhand.com>
 
 	* configure.ac: Check the --with switches as soon as we have them,

clutter/cogl/gles/cogl-fixed-fragment-shader.glsl

@@ -12,6 +12,20 @@ uniform bool       alpha_only;
 uniform bool       fog_enabled;
 uniform vec4       fog_color;
 
+/* Alpha test options */
+uniform bool       alpha_test_enabled;
+uniform int        alpha_test_func;
+uniform float      alpha_test_ref;
+
+/* Alpha test functions */
+const int GL_NEVER    = 0x0200;
+const int GL_LESS     = 0x0201;
+const int GL_EQUAL    = 0x0202;
+const int GL_LEQUAL   = 0x0203;
+const int GL_GREATER  = 0x0204;
+const int GL_NOTEQUAL = 0x0205;
+const int GL_GEQUAL   = 0x0206;
+
 void
 main (void)
 {
@@ -35,4 +49,41 @@ main (void)
   if (fog_enabled)
     /* Mix the calculated color with the fog color */
     gl_FragColor.rgb = mix (fog_color.rgb, gl_FragColor.rgb, fog_amount);
+
+  /* Alpha testing */
+  if (alpha_test_enabled)
+    {
+      if (alpha_test_func == GL_NEVER)
+	discard;
+      else if (alpha_test_func == GL_LESS)
+	{
+	  if (gl_FragColor.a >= alpha_test_ref)
+	    discard;
+	}
+      else if (alpha_test_func == GL_EQUAL)
+	{
+	  if (gl_FragColor.a != alpha_test_ref)
+	    discard;
+	}
+      else if (alpha_test_func == GL_LEQUAL)
+	{
+	  if (gl_FragColor.a > alpha_test_ref)
+	    discard;
+	}
+      else if (alpha_test_func == GL_GREATER)
+	{
+	  if (gl_FragColor.a <= alpha_test_ref)
+	    discard;
+	}
+      else if (alpha_test_func == GL_NOTEQUAL)
+	{
+	  if (gl_FragColor.a == alpha_test_ref)
+	    discard;
+	}
+      else if (alpha_test_func == GL_GEQUAL)
+	{
+	  if (gl_FragColor.a < alpha_test_ref)
+	    discard;
+	}
+    }
 }

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

@@ -164,6 +164,13 @@ cogl_gles2_wrapper_init (CoglGles2Wrapper *wrapper)
   wrapper->fog_color_uniform
     = glGetUniformLocation (wrapper->program, "fog_color");
 
+  wrapper->alpha_test_enabled_uniform
+    = glGetUniformLocation (wrapper->program, "alpha_test_enabled");
+  wrapper->alpha_test_func_uniform
+    = glGetUniformLocation (wrapper->program, "alpha_test_func");
+  wrapper->alpha_test_ref_uniform
+    = glGetUniformLocation (wrapper->program, "alpha_test_ref");
+
   /* Always use the first texture unit */
   glUniform1i (wrapper->bound_texture_uniform, 0);
 
@@ -184,6 +191,10 @@ cogl_gles2_wrapper_init (CoglGles2Wrapper *wrapper)
   cogl_wrap_glFogx (GL_FOG_START, 0);
   cogl_wrap_glFogx (GL_FOG_END, 1);
   cogl_wrap_glFogxv (GL_FOG_COLOR, default_fog_color);
+
+  /* Initialize alpha testing */
+  cogl_wrap_glDisable (GL_ALPHA_TEST);
+  cogl_wrap_glAlphaFunc (GL_ALWAYS, 0.0f);
 }
 
 void
@@ -567,6 +578,10 @@ cogl_wrap_glEnable (GLenum cap)
       glUniform1i (w->fog_enabled_uniform, GL_TRUE);
       break;
 
+    case GL_ALPHA_TEST:
+      glUniform1i (w->alpha_test_enabled_uniform, GL_TRUE);
+      break;
+
     default:
       glEnable (cap);
     }
@@ -587,6 +602,10 @@ cogl_wrap_glDisable (GLenum cap)
       glUniform1i (w->fog_enabled_uniform, GL_FALSE);
       break;
 
+    case GL_ALPHA_TEST:
+      glUniform1i (w->alpha_test_enabled_uniform, GL_FALSE);
+      break;
+
     default:
       glDisable (cap);
     }
@@ -629,7 +648,15 @@ cogl_wrap_glDisableClientState (GLenum array)
 void
 cogl_wrap_glAlphaFunc (GLenum func, GLclampf ref)
 {
-  /* FIXME */
+  _COGL_GET_GLES2_WRAPPER (w, NO_RETVAL);
+
+  if (ref < 0.0f)
+    ref = 0.0f;
+  else if (ref > 1.0f)
+    ref = 1.0f;
+
+  glUniform1i (w->alpha_test_func_uniform, func);
+  glUniform1f (w->alpha_test_ref_uniform, ref);
 }
 
 void
@@ -656,6 +683,23 @@ cogl_gles2_float_array_to_fixed (int size, const GLfloat *floats,
     *(fixeds++) = CLUTTER_FLOAT_TO_FIXED (*(floats++));
 }
 
+void
+cogl_wrap_glGetIntegerv (GLenum pname, GLint *params)
+{
+  _COGL_GET_GLES2_WRAPPER (w, NO_RETVAL);
+
+  switch (pname)
+    {
+    case GL_MAX_CLIP_PLANES:
+      *params = 0;
+      break;
+
+    default:
+      glGetIntegerv (pname, params);
+      break;
+    }
+}
+
 void
 cogl_wrap_glGetFixedv (GLenum pname, GLfixed *params)
 {

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

@@ -57,6 +57,10 @@ struct _CoglGles2Wrapper
   GLint     fog_end_uniform;
   GLint     fog_color_uniform;
 
+  GLint     alpha_test_enabled_uniform;
+  GLint     alpha_test_func_uniform;
+  GLint     alpha_test_ref_uniform;
+
   GLuint    matrix_mode;
   GLfloat   modelview_stack[COGL_GLES2_MODELVIEW_STACK_SIZE * 16];
   GLuint    modelview_stack_pos;
@@ -149,6 +153,7 @@ void cogl_wrap_glColor4x (GLclampx r, GLclampx g, GLclampx b, GLclampx a);
 
 void cogl_wrap_glClipPlanex (GLenum plane, GLfixed *equation);
 
+void cogl_wrap_glGetIntegerv (GLenum pname, GLint *params);
 void cogl_wrap_glGetFixedv (GLenum pname, GLfixed *params);
 
 void cogl_wrap_glFogx (GLenum pname, GLfixed param);
@@ -191,6 +196,7 @@ void cogl_gles2_wrapper_bind_texture (GLenum target, GLuint texture,
 #define cogl_wrap_glAlphaFunc          glAlphaFunc
 #define cogl_wrap_glColor4x            glColor4x
 #define cogl_wrap_glClipPlanex         glClipPlanex
+#define cogl_wrap_glGetIntegerv        glGetIntegerv
 #define cogl_wrap_glGetFixedv          glGetFixedv
 #define cogl_wrap_glFogx               glFogx
 #define cogl_wrap_glFogxv              glFogxv

clutter/cogl/gles/cogl-primitives.c

@@ -172,8 +172,8 @@ _cogl_path_fill_nodes ()
   bounds_w = CLUTTER_FIXED_CEIL (ctx->path_nodes_max.x - ctx->path_nodes_min.x);
   bounds_h = CLUTTER_FIXED_CEIL (ctx->path_nodes_max.y - ctx->path_nodes_min.y);
 
-#if GOT_WORKING_STENCIL_BUFFER
+  if (cogl_features_available (COGL_FEATURE_STENCIL_BUFFER))
-  
+    {
       GE( glClear (GL_STENCIL_BUFFER_BIT) );
 
       GE( cogl_wrap_glEnable (GL_STENCIL_TEST) );
@@ -191,15 +191,16 @@ _cogl_path_fill_nodes ()
       GE( glStencilOp (GL_ZERO, GL_ZERO, GL_ZERO) );
       GE( glColorMask (GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE) );
   
-  
       cogl_rectangle (bounds_x, bounds_y, bounds_w, bounds_h);
   
       GE( cogl_wrap_glDisable (GL_STENCIL_TEST) );
-#else
+    }
+  else
     {
-    /* This is our edge list it stores intersections between our curve and
+      /* This is our edge list it stores intersections between our
-     * scanlines, it should probably be implemented with a data structure
+       * curve and scanlines, it should probably be implemented with a
-     * that has smaller overhead for inserting the curve/scanline intersections.
+       * data structure that has smaller overhead for inserting the
+       * curve/scanline intersections.
        */
       GSList *scanlines[bounds_h];
 
@@ -228,7 +229,7 @@ _cogl_path_fill_nodes ()
 	  gint dy;
 	  gint y;
 
-fill_close:
+	fill_close:
 	  dx = dest_x - prev_x;
 	  dy = dest_y - prev_y;
 
@@ -271,7 +272,8 @@ fill_close:
 	  prev_x = dest_x;
 	  prev_y = dest_y;
 
-        /* if we're on the last knot, fake the first vertex being a next one */
+	  /* if we're on the last knot, fake the first vertex being a
+	     next one */
 	  if (ctx->path_nodes_size == i+1)
 	    {
 	      dest_x = first_x;
@@ -321,7 +323,8 @@ fill_close:
 		x1 = CLUTTER_INT_TO_FIXED (GPOINTER_TO_INT (next->data));
 		y0 = CLUTTER_INT_TO_FIXED (bounds_y + i);
 		y1 = CLUTTER_INT_TO_FIXED (bounds_y + i + 1) + 2048;
-              /* render scanlines 1.0625 high to avoid gaps when transformed */
+		/* render scanlines 1.0625 high to avoid gaps when
+		   transformed */
 
 		coords[span_no * 12 + 0] = x0;
 		coords[span_no * 12 + 1] = y0;
@@ -352,6 +355,5 @@ fill_close:
         g_free (coords);
       }
     }
-#endif
 }
 

clutter/cogl/gles/cogl-texture.c

@@ -381,7 +381,7 @@ _cogl_texture_download_from_gl (CoglTexture *tex,
   bpp = _cogl_get_format_bpp (COGL_PIXEL_FORMAT_RGBA_8888);
   
   /* Viewport needs to have some size and be inside the window for this */
-  GE( glGetIntegerv (GL_VIEWPORT, viewport) );
+  GE( cogl_wrap_glGetIntegerv (GL_VIEWPORT, viewport) );
   
   if (viewport[0] <  0 || viewport[1] <  0 ||
       viewport[2] <= 0 || viewport[3] <= 0)
@@ -422,10 +422,10 @@ _cogl_texture_download_from_gl (CoglTexture *tex,
      still doesn't seem to have an alpha buffer. This might be just
      a PowerVR issue.
   GLint r_bits, g_bits, b_bits, a_bits;
-  GE( glGetIntegerv (GL_ALPHA_BITS, &a_bits) );
+  GE( cogl_wrap_glGetIntegerv (GL_ALPHA_BITS, &a_bits) );
-  GE( glGetIntegerv (GL_RED_BITS, &r_bits) );
+  GE( cogl_wrap_glGetIntegerv (GL_RED_BITS, &r_bits) );
-  GE( glGetIntegerv (GL_GREEN_BITS, &g_bits) );
+  GE( cogl_wrap_glGetIntegerv (GL_GREEN_BITS, &g_bits) );
-  GE( glGetIntegerv (GL_BLUE_BITS, &b_bits) );
+  GE( cogl_wrap_glGetIntegerv (GL_BLUE_BITS, &b_bits) );
   printf ("R bits: %d\n", r_bits);
   printf ("G bits: %d\n", g_bits);
   printf ("B bits: %d\n", b_bits);

clutter/cogl/gles/cogl.c

@@ -482,11 +482,11 @@ _cogl_features_init ()
 
   _COGL_GET_CONTEXT (ctx, NO_RETVAL);
 
-  GE( glGetIntegerv (GL_STENCIL_BITS, &stencil_bits) );
+  GE( cogl_wrap_glGetIntegerv (GL_STENCIL_BITS, &stencil_bits) );
   if (stencil_bits > 0)
     flags |= COGL_FEATURE_STENCIL_BUFFER;
 
-  GE( glGetIntegerv (GL_MAX_CLIP_PLANES, &max_clip_planes) );
+  GE( cogl_wrap_glGetIntegerv (GL_MAX_CLIP_PLANES, &max_clip_planes) );
   if (max_clip_planes >= 4)
     flags |= COGL_FEATURE_FOUR_CLIP_PLANES;
 
@@ -538,13 +538,13 @@ void
 cogl_get_bitmasks (gint *red, gint *green, gint *blue, gint *alpha)
 {
   if (red)
-    GE( glGetIntegerv(GL_RED_BITS, red) );
+    GE( cogl_wrap_glGetIntegerv(GL_RED_BITS, red) );
   if (green)
-    GE( glGetIntegerv(GL_GREEN_BITS, green) );
+    GE( cogl_wrap_glGetIntegerv(GL_GREEN_BITS, green) );
   if (blue)
-    GE( glGetIntegerv(GL_BLUE_BITS, blue) );
+    GE( cogl_wrap_glGetIntegerv(GL_BLUE_BITS, blue) );
   if (alpha)
-    GE( glGetIntegerv(GL_ALPHA_BITS, alpha ) );
+    GE( cogl_wrap_glGetIntegerv(GL_ALPHA_BITS, alpha ) );
 }
 
 void