[175/906] add sin effect (desaturate everything but red shades). still needs some tuning.

gst/gl/Makefile.am

@@ -41,6 +41,7 @@ libgstopengl_la_SOURCES = \
 	effects/gstgleffectsquare.c \
 	effects/gstgleffectlumatocurve.c \
 	effects/gstgleffectrgbtocurve.c \
+	effects/gstgleffectsin.c \
 	effects/gstgleffectglow.c 
 	
 

gst/gl/effects/gstgleffectsin.c

@@ -0,0 +1,61 @@
+/*
+ * 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 void
+gst_gl_effects_sin_callback (gint width, gint height, guint texture, gpointer data)
+{
+  GstGLEffects* effects = GST_GL_EFFECTS (data);
+
+  GstGLShader *shader;
+          
+  shader = g_hash_table_lookup (effects->shaderstable, "sin0");
+  
+  if (!shader) {
+    shader = gst_gl_shader_new ();
+    g_hash_table_insert (effects->shaderstable, "sin0", shader);
+  }
+  
+  g_return_if_fail (
+    gst_gl_shader_compile_and_check (shader, sin_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);
+}
+
+void
+gst_gl_effects_sin (GstGLEffects *effects) {
+  GstGLFilter *filter = GST_GL_FILTER (effects);
+
+  gst_gl_filter_render_to_target (filter, effects->intexture, effects->outtexture,
+				  gst_gl_effects_sin_callback, effects);
+}

gst/gl/effects/gstgleffectssources.c

@@ -277,3 +277,50 @@ const gchar *rgb_to_curve_fragment_source =
 "  outcolor.a = color.a;"
 "  gl_FragColor = outcolor;"
 "}";
+
+const gchar *sin_fragment_source =
+"#extension GL_ARB_texture_rectangle : enable\n"
+"uniform sampler2DRect tex;"
+"vec3 rgb2hsl (vec3 v) "
+"{"
+/* TODO: check this algorythm */
+"  float MIN, MAX;"
+"  float r, g, b;"
+"  float h, l, s;"
+"  float delta;"
+"  h = 0.0; l = 0.0; s = 0.0;"
+"  r = v.r; g = v.g; b = v.b;"
+"  MIN = min (r, min (g, b));"
+"  MAX = max (r, max (g, b));"
+"  delta = MAX - MIN;"
+"  l = (MAX + MIN) / 2.0;"
+"  if ((MAX - MIN) < 0.0001) { h = 0.0; s = 0.0; }"
+"  else {"
+"    if (l <= 0.5) s = (MAX - MIN) / (MAX + MIN);"
+"    else s = (MAX - MIN) / (2.0 - MAX - MIN);"
+"    if (r == MAX) h = (g - b) / delta;"
+"    else if (g == MAX) h = 2.0 + (b - r) / delta;"
+"    else h = 4.0 + (r - g) / delta;"
+"    h *= 60.0;"
+"    if (h < 0.0) h += 360.0;"
+"  }"
+"  return vec3 (h, l, s);"
+"}"
+"void main () {"
+"  vec3 HSL, RGB;"
+"  vec4 color = texture2DRect (tex, vec2(gl_TexCoord[0].st));"
+"  float luma = dot(color.rgb, vec3(0.2125, 0.7154, 0.0721));"
+"  HSL = rgb2hsl (color.rgb);"
+/* move hls discontinuity away from the desired red zone so we can use
+ * smoothstep.. to try: convert degrees in radiants, divide by 2 and
+ * smoothstep sine */
+"  HSL.x += 180.0;"
+"  if ((HSL.x) > 360.0) HSL.x -= 360.0;"
+/* damn, it is extremely hard to get rid of human face reds! */
+/* picked hue is slightly shifted towards violet to prevent this but
+ * still fails.. maybe hsl is not well suited for this */
+"  float a = smoothstep (110.0, 150.0, HSL.x);"
+"  float b = smoothstep (170.0, 210.0, HSL.x);"
+"  float alpha = a - b;"
+"  gl_FragColor = color * alpha + luma * (1.0 - alpha);"
+"}";

gst/gl/effects/gstgleffectssources.h

@@ -37,5 +37,6 @@ const gchar *vconv9_fragment_source;
 const gchar *sum_fragment_source;
 const gchar *luma_to_curve_fragment_source;
 const gchar *rgb_to_curve_fragment_source;
+const gchar *sin_fragment_source;
 
 #endif /* __GST_GL_EFFECTS_SOURCES_H__ */

gst/gl/gstgleffects.c

@@ -68,6 +68,7 @@ typedef enum {
   GST_GL_EFFECT_SEPIA,
   GST_GL_EFFECT_XPRO,
   GST_GL_EFFECT_LUMA_XPRO,
+  GST_GL_EFFECT_SIN,
   GST_GL_EFFECT_GLOW,
   GST_GL_N_EFFECTS
 } GstGLEffectsEffect;
@@ -91,6 +92,7 @@ gst_gl_effects_effect_get_type (void)
     { GST_GL_EFFECT_SEPIA, "Sepia Toning Effect", "sepia" },
     { GST_GL_EFFECT_XPRO, "Cross Processing Effect", "xpro" },
     { GST_GL_EFFECT_LUMA_XPRO, "Luma Cross Processing Effect", "lumaxpro" },
+    { GST_GL_EFFECT_SIN, "All Grey but Red Effect", "sin" },
     { GST_GL_EFFECT_GLOW, "Glow Lighting Effect", "glow" },
     { 0, NULL, NULL }
   };
@@ -145,6 +147,9 @@ gst_gl_effects_set_effect (GstGLEffects *effects, gint effect_type) {
   case GST_GL_EFFECT_LUMA_XPRO:
     effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_luma_xpro;
     break;
+  case GST_GL_EFFECT_SIN:
+    effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_sin;
+    break;
   case GST_GL_EFFECT_GLOW:
     effects->effect = (GstGLEffectProcessFunc) gst_gl_effects_glow;
     break;

gst/gl/gstgleffects.h

@@ -101,6 +101,7 @@ void gst_gl_effects_heat (GstGLEffects *effects);
 void gst_gl_effects_sepia (GstGLEffects *effects);
 void gst_gl_effects_xpro (GstGLEffects *effects);
 void gst_gl_effects_luma_xpro (GstGLEffects *effects);
+void gst_gl_effects_sin (GstGLEffects *effects);
 void gst_gl_effects_glow (GstGLEffects *effects);
 
 G_END_DECLS

tests/examples/gtk/fxtest/fxtest.c

@@ -176,6 +176,7 @@ main (gint argc, gchar * argv[])
   gtk_combo_box_append_text (GTK_COMBO_BOX (combo), "xpro");
   gtk_combo_box_append_text (GTK_COMBO_BOX (combo), "lumaxpro");
   gtk_combo_box_append_text (GTK_COMBO_BOX (combo), "sepia");
+  gtk_combo_box_append_text (GTK_COMBO_BOX (combo), "sin");
   gtk_combo_box_append_text (GTK_COMBO_BOX (combo), "glow");
 
   g_signal_connect (G_OBJECT (combo), "changed", G_CALLBACK (apply_fx), filter);