First Commit

libui-ng/unix/image.c

@@ -0,0 +1,134 @@
+// 27 june 2016
+#include "uipriv_unix.h"
+
+struct uiImage {
+	double width;
+	double height;
+	GPtrArray *images;
+};
+
+static void freeImageRep(gpointer item)
+{
+	cairo_surface_t *cs = (cairo_surface_t *) item;
+
+	cairo_surface_destroy(cs);
+}
+
+uiImage *uiNewImage(double width, double height)
+{
+	uiImage *i;
+
+	i = uiprivNew(uiImage);
+	i->width = width;
+	i->height = height;
+	i->images = g_ptr_array_new_with_free_func(freeImageRep);
+	return i;
+}
+
+void uiFreeImage(uiImage *i)
+{
+	g_ptr_array_free(i->images, TRUE);
+	uiprivFree(i);
+}
+
+void uiImageAppend(uiImage *i, void *pixels, int pixelWidth, int pixelHeight, int byteStride)
+{
+	cairo_surface_t *cs;
+	uint8_t *data, *pix;
+	int realStride;
+	int x, y;
+
+	// note that this is native-endian
+	cs = cairo_image_surface_create(CAIRO_FORMAT_ARGB32,
+		pixelWidth, pixelHeight);
+	if (cairo_surface_status(cs) != CAIRO_STATUS_SUCCESS)
+		/* TODO */;
+	cairo_surface_flush(cs);
+
+	pix = (uint8_t *) pixels;
+	data = (uint8_t *) cairo_image_surface_get_data(cs);
+	realStride = cairo_image_surface_get_stride(cs);
+	for (y = 0; y < pixelHeight; y++) {
+		for (x = 0; x < pixelWidth * 4; x += 4) {
+			union {
+				uint32_t v32;
+				uint8_t v8[4];
+			} v;
+
+			v.v32 = ((uint32_t) (pix[x + 3])) << 24;
+			v.v32 |= ((uint32_t) (pix[x])) << 16;
+			v.v32 |= ((uint32_t) (pix[x + 1])) << 8;
+			v.v32 |= ((uint32_t) (pix[x + 2]));
+			data[x] = v.v8[0];
+			data[x + 1] = v.v8[1];
+			data[x + 2] = v.v8[2];
+			data[x + 3] = v.v8[3];
+		}
+		pix += byteStride;
+		data += realStride;
+	}
+
+	cairo_surface_mark_dirty(cs);
+	g_ptr_array_add(i->images, cs);
+}
+
+struct matcher {
+	cairo_surface_t *best;
+	int distX;
+	int distY;
+	int targetX;
+	int targetY;
+	gboolean foundLarger;
+};
+
+// TODO is this the right algorithm?
+static void match(gpointer surface, gpointer data)
+{
+	cairo_surface_t *cs = (cairo_surface_t *) surface;
+	struct matcher *m = (struct matcher *) data;
+	int x, y;
+	int x2, y2;
+
+	x = cairo_image_surface_get_width(cs);
+	y = cairo_image_surface_get_height(cs);
+	if (m->best == NULL)
+		goto writeMatch;
+
+	if (x < m->targetX && y < m->targetY)
+		if (m->foundLarger)
+			// always prefer larger ones
+			return;
+	if (x >= m->targetX && y >= m->targetY && !m->foundLarger)
+		// we set foundLarger below
+		goto writeMatch;
+
+	x2 = abs(m->targetX - x);
+	y2 = abs(m->targetY - y);
+	if (x2 < m->distX && y2 < m->distY)
+		goto writeMatch;
+
+	// TODO weight one dimension? threshhold?
+	return;
+
+writeMatch:
+	// must set this here too; otherwise the first image will never have ths set
+	if (x >= m->targetX && y >= m->targetY && !m->foundLarger)
+		m->foundLarger = TRUE;
+	m->best = cs;
+	m->distX = abs(m->targetX - x);
+	m->distY = abs(m->targetY - y);
+}
+
+cairo_surface_t *uiprivImageAppropriateSurface(uiImage *i, GtkWidget *w)
+{
+	struct matcher m;
+
+	m.best = NULL;
+	m.distX = G_MAXINT;
+	m.distY = G_MAXINT;
+	m.targetX = i->width * gtk_widget_get_scale_factor(w);
+	m.targetY = i->height * gtk_widget_get_scale_factor(w);
+	m.foundLarger = FALSE;
+	g_ptr_array_foreach(i->images, match, &m);
+	return m.best;
+}