testgradient.c

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/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */

/* Metacity gradient test program */

/* 
 * Copyright (C) 2002 Havoc Pennington
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program 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
 * General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.  */

#include "gradient.h"
#include <gtk/gtk.h>

typedef void (* RenderGradientFunc) (GdkDrawable *drawable,
                                     GdkGC       *gc,
                                     int          width,
                                     int          height);

static void
draw_checkerboard (GdkDrawable *drawable,
                   int          width,
                   int          height)
{
  gint i, j, xcount, ycount;
  GdkGC *gc1, *gc2;
  GdkColor color;
  
#define CHECK_SIZE 10
#define SPACING 2  

  /* It would be a bit more efficient to keep these
   * GC's around instead of recreating on each expose, but
   * this is the lazy/slow way.
   */
  gc1 = gdk_gc_new (drawable);
  color.red = 30000;
  color.green = 30000;
  color.blue = 30000;
  gdk_gc_set_rgb_fg_color (gc1, &color);

  gc2 = gdk_gc_new (drawable);
  color.red = 50000;
  color.green = 50000;
  color.blue = 50000;
  gdk_gc_set_rgb_fg_color (gc2, &color);
  
  xcount = 0;
  i = SPACING;
  while (i < width)
    {
      j = SPACING;
      ycount = xcount % 2; /* start with even/odd depending on row */
      while (j < height)
        {
          GdkGC *gc;
          
          if (ycount % 2)
            gc = gc1;
          else
            gc = gc2;

          /* If we're outside event->area, this will do nothing.
           * It might be mildly more efficient if we handled
           * the clipping ourselves, but again we're feeling lazy.
           */
          gdk_draw_rectangle (drawable,
                              gc,
                              TRUE,
                              i, j,
                              CHECK_SIZE,
                              CHECK_SIZE);

          j += CHECK_SIZE + SPACING;
          ++ycount;
        }

      i += CHECK_SIZE + SPACING;
      ++xcount;
    }
  
  g_object_unref (G_OBJECT (gc1));
  g_object_unref (G_OBJECT (gc2));
}

static void
render_simple (GdkDrawable *drawable,
               GdkGC       *gc,
               int width, int height,
               MetaGradientType type,
               gboolean    with_alpha)
{
  GdkPixbuf *pixbuf;
  GdkColor from, to;
  
  gdk_color_parse ("blue", &from);
  gdk_color_parse ("green", &to);

  pixbuf = meta_gradient_create_simple (width, height,
                                        &from, &to,
                                        type);

  if (with_alpha)
    {
      const unsigned char alphas[] = { 0xff, 0xaa, 0x2f, 0x0, 0xcc, 0xff, 0xff };
      
      if (!gdk_pixbuf_get_has_alpha (pixbuf))
        {
          GdkPixbuf *new_pixbuf;
          
          new_pixbuf = gdk_pixbuf_add_alpha (pixbuf, FALSE, 0, 0, 0);
          g_object_unref (G_OBJECT (pixbuf));
          pixbuf = new_pixbuf;
        }
      
      meta_gradient_add_alpha (pixbuf,
                               alphas, G_N_ELEMENTS (alphas),
                               META_GRADIENT_HORIZONTAL);
      
      draw_checkerboard (drawable, width, height);
    }
    
  gdk_draw_pixbuf (drawable,
                   gc,
                   pixbuf,
                   0, 0,
                   0, 0, width, height,
                   GDK_RGB_DITHER_MAX,
                   0, 0);

  g_object_unref (G_OBJECT (pixbuf));
}

static void
render_vertical_func (GdkDrawable *drawable,
                      GdkGC *gc,
                      int width, int height)
{
  render_simple (drawable, gc, width, height, META_GRADIENT_VERTICAL, FALSE);
}

static void
render_horizontal_func (GdkDrawable *drawable,
                        GdkGC *gc,
                        int width, int height)
{
  render_simple (drawable, gc, width, height, META_GRADIENT_HORIZONTAL, FALSE);
}

static void
render_diagonal_func (GdkDrawable *drawable,
                      GdkGC *gc,
                      int width, int height)
{
  render_simple (drawable, gc, width, height, META_GRADIENT_DIAGONAL, FALSE);
}

static void
render_diagonal_alpha_func (GdkDrawable *drawable,
                            GdkGC *gc,
                            int width, int height)
{
  render_simple (drawable, gc, width, height, META_GRADIENT_DIAGONAL, TRUE);
}

static void
render_multi (GdkDrawable *drawable,
              GdkGC       *gc,
              int width, int height,
              MetaGradientType type)
{
  GdkPixbuf *pixbuf;
#define N_COLORS 5
  GdkColor colors[N_COLORS];

  gdk_color_parse ("red", &colors[0]);
  gdk_color_parse ("blue", &colors[1]);
  gdk_color_parse ("orange", &colors[2]);
  gdk_color_parse ("pink", &colors[3]);
  gdk_color_parse ("green", &colors[4]);

  pixbuf = meta_gradient_create_multi (width, height,
                                       colors, N_COLORS,
                                       type);

  gdk_pixbuf_render_to_drawable (pixbuf,
                                 drawable,
                                 gc,
                                 0, 0,
                                 0, 0, width, height,
                                 GDK_RGB_DITHER_NORMAL,
                                 0, 0);

  g_object_unref (G_OBJECT (pixbuf));
#undef N_COLORS
}

static void
render_vertical_multi_func (GdkDrawable *drawable,
                            GdkGC *gc,
                            int width, int height)
{
  render_multi (drawable, gc, width, height, META_GRADIENT_VERTICAL);
}

static void
render_horizontal_multi_func (GdkDrawable *drawable,
                              GdkGC *gc,
                              int width, int height)
{
  render_multi (drawable, gc, width, height, META_GRADIENT_HORIZONTAL);
}

static void
render_diagonal_multi_func (GdkDrawable *drawable,
                            GdkGC *gc,
                            int width, int height)
{
  render_multi (drawable, gc, width, height, META_GRADIENT_DIAGONAL);
}

static void
render_interwoven_func (GdkDrawable *drawable,
                        GdkGC       *gc,
                        int width, int height)
{
  GdkPixbuf *pixbuf;
#define N_COLORS 4
  GdkColor colors[N_COLORS];

  gdk_color_parse ("red", &colors[0]);
  gdk_color_parse ("blue", &colors[1]);
  gdk_color_parse ("pink", &colors[2]);
  gdk_color_parse ("green", &colors[3]);

  pixbuf = meta_gradient_create_interwoven (width, height,
                                            colors, height / 10,
                                            colors + 2, height / 14);

  gdk_pixbuf_render_to_drawable (pixbuf,
                                 drawable,
                                 gc,
                                 0, 0,
                                 0, 0, width, height,
                                 GDK_RGB_DITHER_NORMAL,
                                 0, 0);

  g_object_unref (G_OBJECT (pixbuf));
}

static gboolean
expose_callback (GtkWidget *widget,
                 GdkEventExpose *event,
                 gpointer data)
{
  RenderGradientFunc func = data;

  (* func) (widget->window,
            widget->style->fg_gc[widget->state],
            widget->allocation.width,
            widget->allocation.height);

  return TRUE;
}

static GtkWidget*
create_gradient_window (const char *title,
                        RenderGradientFunc func)
{
  GtkWidget *window;
  GtkWidget *drawing_area;

  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

  gtk_window_set_title (GTK_WINDOW (window), title);
  
  drawing_area = gtk_drawing_area_new ();

  gtk_widget_set_size_request (drawing_area, 1, 1);

  gtk_window_set_default_size (GTK_WINDOW (window), 175, 175);
  
  g_signal_connect (G_OBJECT (drawing_area),
                    "expose_event",
                    G_CALLBACK (expose_callback),
                    func);

  gtk_container_add (GTK_CONTAINER (window), drawing_area);

  gtk_widget_show_all (window);
  
  return window;
}

static void
meta_gradient_test (void)
{
  GtkWidget *window;

  window = create_gradient_window ("Simple vertical",
                                   render_vertical_func);
  
  window = create_gradient_window ("Simple horizontal",
                                   render_horizontal_func);

  window = create_gradient_window ("Simple diagonal",
                                   render_diagonal_func);

  window = create_gradient_window ("Multi vertical",
                                   render_vertical_multi_func);
  
  window = create_gradient_window ("Multi horizontal",
                                   render_horizontal_multi_func);

  window = create_gradient_window ("Multi diagonal",
                                   render_diagonal_multi_func);

  window = create_gradient_window ("Interwoven",
                                   render_interwoven_func);

  window = create_gradient_window ("Simple diagonal with horizontal multi alpha",
                                   render_diagonal_alpha_func);

}

int
main (int argc, char **argv)
{
  gtk_init (&argc, &argv);

  meta_gradient_test ();

  gtk_main ();

  return 0;
}

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