doc/example-code/example6.c

   1 /*------------------------------------------------------------------------------
   2         Filename: example6.c
   3
   4         Description: Demonstrate how to embed a libgerbv render window into a new
   5                 application to create a custom viewer
   6
   7         Instructions: Make sure you are in the example-code directory, and compile
   8                 this program with the following command (assumes you are using a
   9                 newer version of gtk which uses cairo):
  10
  11         gcc -Wall -g `pkg-config --cflags libgerbv` `pkg-config --libs libgerbv` example6.c -o example6
  12
  13         Run with the following command:
  14
  15         ./example6
  16
  17         Common compiling problems:
  18                 1. If you are compiling gerbv from source, make sure you run
  19                         "make install" before trying to compile this example. This
  20                         ensures libgerbv is correctly installed and can be found.
  21                 2. If you installed gerbv to "/usr/local" (the default), many
  22                         distributions don't correctly point pkgconfig to this target.
  23                         To fix this, add the following to your ~/.bashrc file:
  24
  25                         export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig/:/usr/lib/pkgconfig/
  26 ------------------------------------------------------------------------------*/
  27
  28 /* gerbv.h pulls in all glib and gtk headers for you */
  29 #include "gerbv.h"
  30 #include <cairo.h>
  31
  32 /* this holds our rendering info like window size, scale factor, and translation */
  33 gerbv_render_info_t screenRenderInfo;
  34 /* this holds all our layers */
  35 gerbv_project_t *mainProject;
  36 /* store the drawing area widget globally to simplify the key event handling, to eliminate
  37    the need for an event box */
  38 GtkWidget *drawingarea;
  39
  40 void
  41 example_render_project_to_screen (GdkDrawable *drawable) {
  42         cairo_t *cr = gdk_cairo_create (drawable);
  43
  44         /* this is by far the simplest method of rendering everything */
  45         gerbv_render_all_layers_to_cairo_target (mainProject, cr, &screenRenderInfo);
  46
  47         /* if you know cairo well, feel free to incorporate your own method here,
  48            but this method shows you one possible idea.  With it, you have more flexibilty over
  49            the rendering
  50         int i;
  51         // paint the background white before we draw anything
  52         cairo_set_source_rgba (cr, 1,1,1, 1);
  53         cairo_paint (cr);
  54
  55         // step through all the files
  56         for(i = mainProject->max_files-1; i >= 0; i--) {
  57                 if (mainProject->file[i]) {
  58                         cairo_push_group (cr);
  59                         gerbv_render_layer_to_cairo_target (cr, mainProject->file[i], &screenRenderInfo);
  60                         cairo_pop_group_to_source (cr);
  61                         cairo_paint_with_alpha (cr, 0.70);
  62                 }
  63         } */
  64         cairo_destroy (cr);
  65 }
  66
  67 /* this is called when the window size changes, and also during startup */
  68 gboolean
  69 example_callbacks_drawingarea_configure_event (GtkWidget *widget, GdkEventConfigure *event)
  70 {
  71         GdkDrawable *drawable = widget->window;
  72
  73         /* figure out how large the window is, and then fit the rendered images inside
  74            the specified window */
  75         gdk_drawable_get_size (drawable, &screenRenderInfo.displayWidth, &screenRenderInfo.displayHeight);
  76         gerbv_render_zoom_to_fit_display (mainProject, &screenRenderInfo);
  77
  78         /* GTK should now automatically expose the window, so no need to do it manually */
  79         return TRUE;
  80 }
  81
  82 /* this is called any time the window needs to redraw (another window moved in front of
  83     it, the window was un-minimized, etc) */
  84 gboolean
  85 example_callbacks_drawingarea_expose_event (GtkWidget *widget, GdkEventExpose *event)
  86 {
  87         /* render all the layers */
  88         example_render_project_to_screen(widget->window);
  89         return TRUE;
  90 }
  91
  92 /* do some simple translation based on the arrow keys and "Z" keys */
  93 gboolean
  94 example_callbacks_drawingarea_key_press_event (GtkWidget *widget, GdkEventKey *event)
  95 {
  96         switch(event->keyval) {
  97                 case GDK_Up:
  98                         /* cairo renders positive Y as down, so keep the sign in mind */
  99                         screenRenderInfo.lowerLeftY -= 0.1;
 100                         break;
 101                 case GDK_Down:
 102                         screenRenderInfo.lowerLeftY += 0.1;
 103                         break;
 104                 case GDK_Left:
 105                         screenRenderInfo.lowerLeftX += 0.1;
 106                         break;
 107                 case GDK_Right:
 108                         screenRenderInfo.lowerLeftX -= 0.1;
 109                         break;
 110                 case GDK_z:
 111                         /* notice the lower left corner doesn't move with this method...
 112                            to do a "true" zoom in, refer to render.c and see how Gerber Viewer
 113                            does it */
 114                         screenRenderInfo.scaleFactorX += screenRenderInfo.scaleFactorX/3;
 115                         screenRenderInfo.scaleFactorY += screenRenderInfo.scaleFactorY/3;
 116                         break;
 117                 case GDK_Z:
 118                         screenRenderInfo.scaleFactorX -= screenRenderInfo.scaleFactorX/3;
 119                         screenRenderInfo.scaleFactorY -= screenRenderInfo.scaleFactorY/3;
 120                         break;
 121                 default:
 122                         break;
 123         }
 124         /* render everything again by forcing an expose event */
 125         GdkRectangle update_rect;
 126
 127         update_rect.x = 0;
 128         update_rect.y = 0;
 129         update_rect.width = screenRenderInfo.displayWidth;
 130         update_rect.height = screenRenderInfo.displayHeight;
 131
 132         /* force the drawing area to have an expose_event, thus redrawing the window */
 133         gdk_window_invalidate_rect (drawingarea->window, &update_rect, FALSE);
 134         return TRUE;
 135 }
 136
 137 void
 138 example_create_GUI (void){
 139         GtkWidget *mainWindow;
 140
 141         mainWindow = gtk_window_new (GTK_WINDOW_TOPLEVEL);
 142         gtk_window_set_default_size((GtkWindow *)mainWindow, 400, 400);
 143
 144         gtk_window_set_title (GTK_WINDOW (mainWindow), "Example 6");
 145
 146         /* a drawing area is the easiest way to make a custom cairo renderer */
 147         drawingarea = gtk_drawing_area_new();
 148         gtk_container_add (GTK_CONTAINER (mainWindow), drawingarea);
 149
 150         /* hook up the signals we need to connect to */
 151         gtk_signal_connect(GTK_OBJECT(drawingarea), "expose_event",
 152                        GTK_SIGNAL_FUNC(example_callbacks_drawingarea_expose_event), NULL);
 153         gtk_signal_connect(GTK_OBJECT(drawingarea),"configure_event",
 154                        GTK_SIGNAL_FUNC(example_callbacks_drawingarea_configure_event), NULL);
 155         gtk_signal_connect(GTK_OBJECT(mainWindow), "key_press_event",
 156                        GTK_SIGNAL_FUNC(example_callbacks_drawingarea_key_press_event), NULL);
 157         gtk_signal_connect_after(GTK_OBJECT(mainWindow), "delete_event",
 158                        GTK_SIGNAL_FUNC(gtk_main_quit), NULL);
 159
 160         gtk_widget_show_all (mainWindow);
 161 }
 162
 163 int
 164 main(int argc, char *argv[]) {
 165         /* create the top level libgerbv structure */
 166         mainProject = gerbv_create_project();
 167
 168         /* make sure we change the render type to "cairo" instead of the GDK alternative */
 169         screenRenderInfo.renderType = GERBV_RENDER_TYPE_CAIRO_HIGH_QUALITY;
 170
 171         /* parse 2 Gerber files */
 172         gerbv_open_layer_from_filename (mainProject, "example1-input.gbx");
 173         gerbv_open_layer_from_filename (mainProject, "example2-input.gbx");
 174
 175         /* make sure we parsed the files */
 176         if ((mainProject->file[0] == NULL) || (mainProject->file[1] == NULL))
 177                 g_error ("There was an error parsing the files.");
 178
 179         /* start up the gtk engine and create our GUI */
 180         gtk_init (&argc, &argv);
 181         example_create_GUI ();
 182
 183         /* start the main GUI loop...it will stay in this function call until you exit */
 184         gtk_main();
 185
 186         /* destroy the project, which will in turn destroy all child images */
 187         gerbv_destroy_project (mainProject);
 188         return 0;
 189 }