sobel: move some highly duplicated code into glfilter

Add a new convenience function in GstGLFilter that just draws an input
texture to a target texture using a simple shader with just a "tex"
uniform sampler.
Move draw_texture from glfiltersobel to glfilter. Still need to update
other plugins to this.

3 files changed, 74 insertions, 104 deletions

diff --git a/gst-libs/gst/gl/gstglfilter.c b/gst-libs/gst/gl/gstglfilter.c
index 087e8be..2f0e6ec 100644
--- a/gst-libs/gst/gl/gstglfilter.c
+++ b/gst-libs/gst/gl/gstglfilter.c
@@ -223,10 +223,12 @@ gst_gl_filter_reset (GstGLFilter * filter)
     g_object_unref (filter->display);
     filter->display = NULL;
   }
+
   filter->width = 0;
   filter->height = 0;
   filter->fbo = 0;
   filter->depthbuffer = 0;
+  filter->default_shader = NULL;
   filter->external_gl_context = 0;
 }
 
@@ -252,7 +254,8 @@ gst_gl_filter_start (GstBaseTransform * bt)
     else {
       /* this gl filter is a sink in terms of the gl chain */
       filter->display = gst_gl_display_new ();
-      gst_gl_display_create_context (filter->display, filter->external_gl_context);
+      gst_gl_display_create_context (filter->display,
+          filter->external_gl_context);
     }
   }
 
@@ -442,3 +445,55 @@ gst_gl_filter_render_to_target (GstGLFilter * filter,
       0, filter->width, 0, filter->height,
       GST_GL_DISPLAY_PROJECTION_ORTHO2D, data);
 }
+
+static void
+_draw_with_shader_cb (gint width, gint height, guint texture, gpointer stuff)
+{
+  GstGLFilter *filter = GST_GL_FILTER (stuff);
+
+  glMatrixMode (GL_PROJECTION);
+  glLoadIdentity ();
+
+  gst_gl_shader_use (filter->default_shader);
+
+  glActiveTexture (GL_TEXTURE1);
+  glEnable (GL_TEXTURE_RECTANGLE_ARB);
+  glBindTexture (GL_TEXTURE_RECTANGLE_ARB, texture);
+  glDisable (GL_TEXTURE_RECTANGLE_ARB);
+
+  gst_gl_shader_set_uniform_1i (filter->default_shader, "tex", 1);
+
+  gst_gl_filter_draw_texture (filter, texture);
+}
+
+/* attach target to a FBO, use shader, pass input as "tex" uniform to
+ * the shader, render input to a quad */
+void
+gst_gl_filter_render_to_target_with_shader (GstGLFilter * filter,
+    GLuint input, GLuint target, GstGLShader * shader)
+{
+  filter->default_shader = shader;
+  gst_gl_filter_render_to_target (filter, input, target, _draw_with_shader_cb,
+      filter);
+}
+
+void
+gst_gl_filter_draw_texture (GstGLFilter * filter, GLuint texture)
+{
+  glActiveTexture (GL_TEXTURE0);
+  glEnable (GL_TEXTURE_RECTANGLE_ARB);
+  glBindTexture (GL_TEXTURE_RECTANGLE_ARB, texture);
+
+  glBegin (GL_QUADS);
+
+  glTexCoord2f (0.0, 0.0);
+  glVertex2f (-1.0, -1.0);
+  glTexCoord2f ((gfloat) filter->width, 0.0);
+  glVertex2f (1.0, -1.0);
+  glTexCoord2f ((gfloat) filter->width, (gfloat) filter->height);
+  glVertex2f (1.0, 1.0);
+  glTexCoord2f (0.0, (gfloat) filter->height);
+  glVertex2f (-1.0, 1.0);
+
+  glEnd ();
+}
diff --git a/gst-libs/gst/gl/gstglfilter.h b/gst-libs/gst/gl/gstglfilter.h
index 0d24b52..f97c91d 100644
--- a/gst-libs/gst/gl/gstglfilter.h
+++ b/gst-libs/gst/gl/gstglfilter.h
@@ -64,6 +64,8 @@ struct _GstGLFilter
   GLuint fbo;
   GLuint depthbuffer;
 
+  GstGLShader *default_shader;
+
   gulong external_gl_context;
 };
 
@@ -90,7 +92,11 @@ void
 gst_gl_filter_render_to_target (GstGLFilter *filter, 
 				GLuint input, GLuint target,
 				GLCB func, gpointer data);
+void
+gst_gl_filter_render_to_target_with_shader (GstGLFilter * filter,
+                                            GLuint input, GLuint target, GstGLShader *shader);
 
+void gst_gl_filter_draw_texture (GstGLFilter *filter, GLuint texture);
 
 G_END_DECLS
 
diff --git a/gst/gl/gstglfiltersobel.c b/gst/gl/gstglfiltersobel.c
index 535d971..5321789 100644
--- a/gst/gl/gstglfiltersobel.c
+++ b/gst/gl/gstglfiltersobel.c
@@ -1,6 +1,6 @@
 /*
  * GStreamer
- * Copyright (C) 2008 Filippo Argiolas <filippo.argiolas@gmail.com>
+ * Copyright (C) 2008-2010 Filippo Argiolas <filippo.argiolas@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ -59,19 +59,11 @@ static void gst_gl_filtersobel_set_property (GObject * object, guint prop_id,
 static void gst_gl_filtersobel_get_property (GObject * object, guint prop_id,
     GValue * value, GParamSpec * pspec);
 static void gst_gl_filter_filtersobel_reset (GstGLFilter * filter);
-static void gst_gl_filtersobel_draw_texture (GstGLFilterSobel * filtersobel,
-    GLuint tex);
 
 static void gst_gl_filtersobel_init_shader (GstGLFilter * filter);
 static gboolean gst_gl_filtersobel_filter (GstGLFilter * filter,
     GstGLBuffer * inbuf, GstGLBuffer * outbuf);
 
-static void gst_gl_filtersobel_desaturate (gint width, gint height,
-    guint texture, gpointer stuff);
-static void gst_gl_filtersobel_hconv (gint width, gint height, guint texture,
-    gpointer stuff);
-static void gst_gl_filtersobel_vconv (gint width, gint height, guint texture,
-    gpointer stuff);
 static void gst_gl_filtersobel_length (gint width, gint height, guint texture,
     gpointer stuff);
 
@@ -216,114 +208,31 @@ gst_gl_filtersobel_init_shader (GstGLFilter * filter)
       sep_sobel_length_fragment_source, &filtersobel->len);
 }
 
-static void
-gst_gl_filtersobel_draw_texture (GstGLFilterSobel * filtersobel, GLuint tex)
-{
-  GstGLFilter *filter = GST_GL_FILTER (filtersobel);
-
-  glActiveTexture (GL_TEXTURE0);
-  glEnable (GL_TEXTURE_RECTANGLE_ARB);
-  glBindTexture (GL_TEXTURE_RECTANGLE_ARB, tex);
-
-  glBegin (GL_QUADS);
-
-  glTexCoord2f (0.0, 0.0);
-  glVertex2f (-1.0, -1.0);
-  glTexCoord2f ((gfloat) filter->width, 0.0);
-  glVertex2f (1.0, -1.0);
-  glTexCoord2f ((gfloat) filter->width, (gfloat) filter->height);
-  glVertex2f (1.0, 1.0);
-  glTexCoord2f (0.0, (gfloat) filter->height);
-  glVertex2f (-1.0, 1.0);
-
-  glEnd ();
-}
-
 static gboolean
 gst_gl_filtersobel_filter (GstGLFilter * filter, GstGLBuffer * inbuf,
     GstGLBuffer * outbuf)
 {
   GstGLFilterSobel *filtersobel = GST_GL_FILTERSOBEL (filter);
 
-  gst_gl_filter_render_to_target (filter, inbuf->texture,
-      filtersobel->midtexture[0], gst_gl_filtersobel_desaturate, filtersobel);
-  gst_gl_filter_render_to_target (filter, filtersobel->midtexture[0],
-      filtersobel->midtexture[1], gst_gl_filtersobel_hconv, filtersobel);
-  gst_gl_filter_render_to_target (filter, filtersobel->midtexture[1],
-      filtersobel->midtexture[0], gst_gl_filtersobel_vconv, filtersobel);
+  gst_gl_filter_render_to_target_with_shader (filter, inbuf->texture,
+      filtersobel->midtexture[0], filtersobel->desat);
+  gst_gl_filter_render_to_target_with_shader (filter,
+      filtersobel->midtexture[0], filtersobel->midtexture[1],
+      filtersobel->hconv);
+  gst_gl_filter_render_to_target_with_shader (filter,
+      filtersobel->midtexture[1], filtersobel->midtexture[0],
+      filtersobel->vconv);
   gst_gl_filter_render_to_target (filter, filtersobel->midtexture[0],
       outbuf->texture, gst_gl_filtersobel_length, filtersobel);
   return TRUE;
 }
 
 static void
-gst_gl_filtersobel_desaturate (gint width, gint height, guint texture,
-    gpointer stuff)
-{
-  GstGLFilterSobel *filtersobel = GST_GL_FILTERSOBEL (stuff);
-
-  glMatrixMode (GL_PROJECTION);
-  glLoadIdentity ();
-
-  gst_gl_shader_use (filtersobel->desat);
-
-  glActiveTexture (GL_TEXTURE1);
-  glEnable (GL_TEXTURE_RECTANGLE_ARB);
-  glBindTexture (GL_TEXTURE_RECTANGLE_ARB, texture);
-  glDisable (GL_TEXTURE_RECTANGLE_ARB);
-
-  gst_gl_shader_set_uniform_1i (filtersobel->desat, "tex", 1);
-
-  gst_gl_filtersobel_draw_texture (filtersobel, texture);
-}
-
-static void
-gst_gl_filtersobel_hconv (gint width, gint height, guint texture,
-    gpointer stuff)
-{
-  GstGLFilterSobel *filtersobel = GST_GL_FILTERSOBEL (stuff);
-
-  glMatrixMode (GL_PROJECTION);
-  glLoadIdentity ();
-
-  gst_gl_shader_use (filtersobel->hconv);
-
-  glActiveTexture (GL_TEXTURE1);
-  glEnable (GL_TEXTURE_RECTANGLE_ARB);
-  glBindTexture (GL_TEXTURE_RECTANGLE_ARB, texture);
-  glDisable (GL_TEXTURE_RECTANGLE_ARB);
-
-  gst_gl_shader_set_uniform_1i (filtersobel->hconv, "tex", 1);
-
-  gst_gl_filtersobel_draw_texture (filtersobel, texture);
-}
-
-static void
-gst_gl_filtersobel_vconv (gint width, gint height, guint texture,
-    gpointer stuff)
-{
-  GstGLFilterSobel *filtersobel = GST_GL_FILTERSOBEL (stuff);
-
-  glMatrixMode (GL_PROJECTION);
-  glLoadIdentity ();
-
-  gst_gl_shader_use (filtersobel->vconv);
-
-  glActiveTexture (GL_TEXTURE1);
-  glEnable (GL_TEXTURE_RECTANGLE_ARB);
-  glBindTexture (GL_TEXTURE_RECTANGLE_ARB, texture);
-  glDisable (GL_TEXTURE_RECTANGLE_ARB);
-
-  gst_gl_shader_set_uniform_1i (filtersobel->vconv, "tex", 1);
-
-  gst_gl_filtersobel_draw_texture (filtersobel, texture);
-}
-
-static void
 gst_gl_filtersobel_length (gint width, gint height, guint texture,
     gpointer stuff)
 {
-  GstGLFilterSobel *filtersobel = GST_GL_FILTERSOBEL (stuff);
+  GstGLFilter *filter = GST_GL_FILTER (stuff);
+  GstGLFilterSobel *filtersobel = GST_GL_FILTERSOBEL (filter);
 
   glMatrixMode (GL_PROJECTION);
   glLoadIdentity ();
@@ -339,5 +248,5 @@ gst_gl_filtersobel_length (gint width, gint height, guint texture,
   gst_gl_shader_set_uniform_1i (filtersobel->len, "invert",
       filtersobel->invert);
 
-  gst_gl_filtersobel_draw_texture (filtersobel, texture);
+  gst_gl_filter_draw_texture (filter, texture);
 }