gstreamer/gst/gl/effects/gstgleffectglow.c

/*
 * GStreamer
 * Copyright (C) 2008 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
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#include <gstgleffects.h>

static gfloat gauss_kernel[9] = { 0.060493, 0.075284, 0.088016, 
                                  0.096667, 0.099736, 0.096667, 
                                  0.088016, 0.075284, 0.060493 };

static void
gst_gl_effects_glow_step_one (gint width, gint height, guint texture, gpointer data)
{
  GstGLEffects* effects = GST_GL_EFFECTS (data);

  GstGLShader *shader;
          
  shader = g_hash_table_lookup (effects->shaderstable, "glow0");
  
  if (!shader) {
    shader = gst_gl_shader_new ();
    g_hash_table_insert (effects->shaderstable, "glow0", shader);
  }
  
  g_return_if_fail (
    gst_gl_shader_compile_and_check (shader, luma_threshold_fragment_source,
				     GST_GL_SHADER_FRAGMENT_SOURCE));

  glMatrixMode (GL_PROJECTION);
  glLoadIdentity ();
  
  gst_gl_shader_use (shader);

  glActiveTexture (GL_TEXTURE0);
  glEnable (GL_TEXTURE_RECTANGLE_ARB);
  glBindTexture (GL_TEXTURE_RECTANGLE_ARB, texture);
     
  gst_gl_shader_set_uniform_1i (shader, "tex", 0);
  
  gst_gl_effects_draw_texture (effects, texture);
}

static void
gst_gl_effects_glow_step_two (gint width, gint height, guint texture, gpointer stuff)
{
  GstGLEffects* effects = GST_GL_EFFECTS (stuff);
  GstGLShader *shader;
          
  /* hard coded kernel, it could be easily generated at runtime with a
   * property to change standard deviation */

  shader = g_hash_table_lookup (effects->shaderstable, "glow1");
  
  if (!shader) {
    shader = gst_gl_shader_new ();
    g_hash_table_insert (effects->shaderstable, "glow1", shader);
  }
  
  g_return_if_fail (
    gst_gl_shader_compile_and_check (shader, hconv9_fragment_source,
				     GST_GL_SHADER_FRAGMENT_SOURCE));

  glMatrixMode (GL_PROJECTION);
  glLoadIdentity ();

  gst_gl_shader_use (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 (shader, "tex", 1);

  gst_gl_shader_set_uniform_1fv (shader, "kernel", 9, gauss_kernel);
  gst_gl_shader_set_uniform_1f (shader, "norm_const", 0.740656);
  gst_gl_shader_set_uniform_1f (shader, "norm_offset", 0.0);

  gst_gl_effects_draw_texture (effects, texture);
}

void
gst_gl_effects_glow_step_three (gint width, gint height, guint texture, gpointer stuff)
{
  GstGLEffects* effects = GST_GL_EFFECTS (stuff);
  GstGLShader *shader;

  shader = g_hash_table_lookup (effects->shaderstable, "glow2");
  
  if (!shader) {
    shader = gst_gl_shader_new ();
    g_hash_table_insert (effects->shaderstable, "glow2", shader);
  }
  
  g_return_if_fail (
    gst_gl_shader_compile_and_check (shader, vconv9_fragment_source,
				     GST_GL_SHADER_FRAGMENT_SOURCE));

  glMatrixMode (GL_PROJECTION);
  glLoadIdentity ();

  gst_gl_shader_use (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 (shader, "tex", 1);

  gst_gl_shader_set_uniform_1fv (shader, "kernel", 9, gauss_kernel);
  gst_gl_shader_set_uniform_1f (shader, "norm_const", 0.740656);
  gst_gl_shader_set_uniform_1f (shader, "norm_offset", 0.0);

  gst_gl_effects_draw_texture (effects, texture);
}

void
gst_gl_effects_glow_step_four (gint width, gint height, guint texture, gpointer stuff)
{
  GstGLEffects* effects = GST_GL_EFFECTS (stuff);
  GstGLShader *shader;

  shader = g_hash_table_lookup (effects->shaderstable, "glow3");
  
  if (!shader) {
    shader = gst_gl_shader_new ();
    g_hash_table_insert (effects->shaderstable, "glow3", shader);
  }
  
  g_return_if_fail (
    gst_gl_shader_compile_and_check (shader, sum_fragment_source,
				     GST_GL_SHADER_FRAGMENT_SOURCE));

  glMatrixMode (GL_PROJECTION);
  glLoadIdentity ();

  gst_gl_shader_use (shader);

  glActiveTexture (GL_TEXTURE2);
  glEnable (GL_TEXTURE_RECTANGLE_ARB);
  glBindTexture (GL_TEXTURE_RECTANGLE_ARB, effects->intexture);
  glDisable(GL_TEXTURE_RECTANGLE_ARB);
  
  gst_gl_shader_set_uniform_1f (shader, "alpha", 1.0);
  gst_gl_shader_set_uniform_1i (shader, "base", 2);
    
  glActiveTexture (GL_TEXTURE1);
  glEnable (GL_TEXTURE_RECTANGLE_ARB);
  glBindTexture (GL_TEXTURE_RECTANGLE_ARB, texture);
  glDisable(GL_TEXTURE_RECTANGLE_ARB);
  
  gst_gl_shader_set_uniform_1f (shader, "beta", 1/3.5);
  gst_gl_shader_set_uniform_1i (shader, "blend", 1);

  gst_gl_effects_draw_texture (effects, texture);
}

void
gst_gl_effects_glow (GstGLEffects *effects) {
  GstGLFilter *filter = GST_GL_FILTER (effects);

  /* threshold */
  gst_gl_filter_render_to_target (filter, effects->intexture, effects->midtexture[0],
				  gst_gl_effects_glow_step_one, effects);
  /* blur */
  gst_gl_filter_render_to_target (filter, effects->midtexture[0], effects->midtexture[1],
				  gst_gl_effects_glow_step_two, effects);
  gst_gl_filter_render_to_target (filter, effects->midtexture[1], effects->midtexture[2],
                                  gst_gl_effects_glow_step_three, effects);
  /* add blurred luma to intexture */
  gst_gl_filter_render_to_target (filter, effects->midtexture[2], effects->outtexture,
                                  gst_gl_effects_glow_step_four, effects);
}