Add capture.c: OpenCV capture displayed with GTK+3

2 files changed, 260 insertions, 3 deletions

diff --git a/Makefile b/Makefile
index fce35b1..65c0cfe 100644
--- a/Makefile
+++ b/Makefile
@@ -5,14 +5,15 @@ CFLAGS = -ggdb -std=c99 -pedantic -Wall $(DEFINES) \
 LDFLAGS = $(LIBS) -lm \
 	  $(shell pkg-config --libs gdk-pixbuf-2.0 glib-2.0 gthread-2.0)
 
-PROGS = wimmel wimmel_gl roi
-OBJS = wimmel.o wimmel_gl.o util.o roi.o
+PROGS = wimmel wimmel_gl roi capture
+OBJS = wimmel.o wimmel_gl.o util.o roi.o capture.o
 
 all: $(PROGS)
 
 wimmel: wimmel.o util.o
 wimmel_gl: wimmel_gl.o util.o
 roi: roi.o
+capture: capture.o
 
 .PHONY: clean all
 
@@ -24,12 +25,17 @@ roi: roi.o
 
 
 wimmel_gl:
-	$(CC) $(LDFLAGS) `pkg-config --cflags --libs egl glesv2` -o $@ $+
+	$(CC) $(LDFLAGS) `pkg-config --cflags --libs egl glesv2` -o $@ $+ 
 
 roi.o: roi.c
 	$(CC) $(CFLAGS) `pkg-config --cflags gtk+-3.0` -c -o $@ $<
 roi:
 	$(CC) $(LDFLAGS) `pkg-config --libs gtk+-3.0` -o $@ $+
 
+capture.o: capture.c
+	$(CC) $(CFLAGS) `pkg-config --cflags gtk+-3.0 opencv` -c -o $@ $<
+capture:
+	$(CC) $(LDFLAGS) `pkg-config --libs gtk+-3.0 opencv` -o $@ $+
+
 clean:
 	rm -f $(PROGS) $(OBJS)
diff --git a/capture.c b/capture.c
new file mode 100644
index 0000000..2a02d32
--- /dev/null
+++ b/capture.c
@@ -0,0 +1,251 @@
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <glib.h>
+#include <gtk/gtk.h>
+
+#include <cv.h>
+#include <highgui.h>
+
+/* Only available as of GTK 3.4 */
+#ifndef GDK_BUTTON_PRIMARY
+#define GDK_BUTTON_PRIMARY 1
+#endif
+
+struct ct {
+	GtkWidget *window;
+	GtkWidget *drawing_area;
+	cairo_surface_t *surface;
+
+	CvCapture *capture;
+	gint timer;
+
+	gboolean doing_rubberband;
+	struct {
+		double x1, y1, x2, y2;
+	} rubberband;
+};
+
+static inline void
+calc_rubberband_rect(struct ct *ct,
+		     double *x, double *y,
+		     double *width, double *height)
+{
+	*x = MIN(ct->rubberband.x1, ct->rubberband.x2);
+	*y = MIN(ct->rubberband.y1, ct->rubberband.y2);
+	*width  = ABS(ct->rubberband.x1 - ct->rubberband.x2);
+	*height = ABS(ct->rubberband.y1 - ct->rubberband.y2);
+}
+
+static gboolean
+motion_notify_event(GtkWidget *widget, GdkEventMotion *event, gpointer userdata)
+{
+	struct ct *ct = userdata;
+
+	if (ct->doing_rubberband) {
+		ct->rubberband.x2 = event->x;
+		ct->rubberband.y2 = event->y;
+		gtk_widget_queue_draw(ct->drawing_area);
+	}
+
+	return TRUE;
+}
+
+static gboolean
+button_press_event(GtkWidget *widget, GdkEventButton *event, gpointer userdata)
+{
+	struct ct *ct = userdata;
+
+	switch (event->button) {
+	case GDK_BUTTON_PRIMARY:
+		ct->rubberband.x1 = event->x;
+		ct->rubberband.x2 = event->x;
+		ct->rubberband.y1 = event->y;
+		ct->rubberband.y2 = event->y;
+
+		ct->doing_rubberband = TRUE;
+		return FALSE;
+	default:
+		return TRUE;
+	}
+}
+
+static gboolean
+button_release_event(GtkWidget *widget, GdkEventButton *event, gpointer userdata)
+{
+	struct ct *ct = userdata;
+
+	if (event->button != GDK_BUTTON_PRIMARY)
+		return TRUE;
+
+	ct->doing_rubberband = FALSE;
+
+	return FALSE;
+}
+
+static gboolean
+key_event(GtkWidget *widget, GdkEventKey *event, gpointer userdata)
+{
+	switch (event->type) {
+	case GDK_KEY_RELEASE:
+		switch (event->keyval) {
+		case GDK_KEY_q:
+		case GDK_KEY_Q:
+			gtk_main_quit();
+			break;
+		}
+		return FALSE;
+	default:
+		return TRUE;
+	}
+}
+
+static void
+draw_rubberband(struct ct *ct, GtkWidget *widget, cairo_t *cr)
+{
+	GtkStyleContext *context;
+	double x, y, width, height;
+
+	context = gtk_widget_get_style_context(widget);
+	gtk_style_context_save(context);
+
+	gtk_style_context_add_class(context, GTK_STYLE_CLASS_RUBBERBAND);
+	calc_rubberband_rect(ct, &x, &y, &width, &height);
+	gtk_render_background(context, cr, x, y, width, height);
+	gtk_render_frame(context, cr, x, y, width, height);
+
+	gtk_style_context_restore(context);
+}
+
+static gboolean
+draw_cb(GtkWidget *widget, cairo_t *cr, gpointer userdata)
+{
+	struct ct *ct = userdata;
+
+	cairo_set_source_surface(cr, ct->surface, 0, 0);
+	cairo_paint(cr);
+
+	if (ct->doing_rubberband)
+		draw_rubberband(ct, widget, cr);
+
+	return FALSE;
+}
+
+static void
+capture(struct ct *ct)
+{
+	IplImage *image;
+	guchar *row1, *row2, *p1, *p2;
+	int x, y;
+
+	image = cvRetrieveFrame(ct->capture, 0);
+	if (!image) {
+		fprintf(stderr, "ERROR: frame is null...\n");
+		exit(EXIT_FAILURE);
+	}
+
+	if (!ct->surface ||
+	    cairo_image_surface_get_width(ct->surface)  != image->width ||
+	    cairo_image_surface_get_height(ct->surface) != image->height) {
+		if (ct->surface)
+			cairo_surface_destroy(ct->surface);
+		ct->surface =
+			cairo_image_surface_create(CAIRO_FORMAT_RGB24,
+						   image->width, image->height);
+	}
+
+	row1 = (guchar *) image->imageData;
+	row2 = cairo_image_surface_get_data(ct->surface);
+	for (y = 0; y < image->height; ++y) {
+		p1 = row1;
+		p2 = row2;
+
+		for (x = 0; x < image->width; ++x) {
+			/*
+			p2[0] = p1[0];
+			p2[1] = p1[1];
+			p2[2] = p1[2];
+			p2[3] = 0;
+			*/
+			memcpy(p2, p1, 3);
+
+			p1 += image->nChannels;
+			p2 += 4;
+		}
+		row1 += image->widthStep;
+		row2 += cairo_image_surface_get_stride(ct->surface);
+	}
+}
+
+static gboolean
+grab(gpointer userdata)
+{
+	struct ct *ct = userdata;
+
+	if (cvGrabFrame(ct->capture) == 0)
+		return TRUE;
+
+	capture(ct);
+	gtk_widget_queue_draw(ct->drawing_area);
+
+	return TRUE;
+}
+
+int
+main(int argc, char *argv[])
+{
+	struct ct ct;
+
+	memset(&ct, 0, sizeof ct);
+
+	gtk_init(&argc, &argv);
+
+	ct.capture = cvCreateCameraCapture(CV_CAP_ANY);
+	if (!ct.capture) {
+		fprintf(stderr, "ERROR: capture is NULL \n");
+		exit(EXIT_FAILURE);
+	}
+
+	cvSetCaptureProperty(ct.capture, CV_CAP_PROP_FRAME_WIDTH,  10000);
+	cvSetCaptureProperty(ct.capture, CV_CAP_PROP_FRAME_HEIGHT, 10000);
+
+	printf("width: %.f, height: %.f\n",
+	       cvGetCaptureProperty(ct.capture, CV_CAP_PROP_FRAME_WIDTH),
+	       cvGetCaptureProperty(ct.capture, CV_CAP_PROP_FRAME_HEIGHT));
+
+	while (cvGrabFrame(ct.capture) == 0);
+	capture(&ct);
+
+	ct.window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
+	ct.drawing_area = gtk_drawing_area_new();
+
+	gtk_widget_set_size_request(ct.drawing_area,
+				    cairo_image_surface_get_width(ct.surface),
+				    cairo_image_surface_get_height(ct.surface));
+
+	gtk_container_add(GTK_CONTAINER(ct.window), ct.drawing_area);
+
+	g_signal_connect(ct.window, "destroy",
+			 G_CALLBACK(gtk_main_quit), NULL);
+	g_signal_connect(ct.window, "key-release-event",
+			 G_CALLBACK(key_event), &ct);
+
+	gtk_widget_set_events(ct.drawing_area, GDK_BUTTON1_MOTION_MASK |
+			      GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK);
+
+	g_signal_connect(ct.drawing_area, "draw", G_CALLBACK(draw_cb), &ct);
+	g_signal_connect(ct.drawing_area, "button-press-event",
+			 G_CALLBACK(button_press_event), &ct);
+	g_signal_connect(ct.drawing_area, "button-release-event",
+			 G_CALLBACK(button_release_event), &ct);
+	g_signal_connect(ct.drawing_area, "motion-notify-event",
+			 G_CALLBACK(motion_notify_event), &ct); 
+
+	g_idle_add(grab, &ct);
+	gtk_widget_show_all(ct.window);
+	gtk_main();
+
+	cvReleaseCapture(&ct.capture);
+
+	return 0;
+}