fix: restore PixbufUtils.mask used by prism_core

ext/morandi_native/mask.h

@@ -0,0 +1,73 @@
+static GdkPixbuf *pixbuf_mask(GdkPixbuf *src, GdkPixbuf *mask)
+{
+	int        s_has_alpha, m_has_alpha;
+	int        s_width, s_height, s_rowstride;
+	int        d_width, d_height, d_rowstride;
+	int        m_width, m_height, m_rowstride;
+	guchar    *s_pix, *sp;
+        guchar    *d_pix, *dp;
+        guchar    *m_pix, *mp;
+	int        i, j, pix_width, alpha, grey;
+	pixel_t    pix;
+	GdkPixbuf *dest;
+
+	g_return_val_if_fail(src != NULL, NULL);
+
+	s_width = gdk_pixbuf_get_width(src);
+	s_height = gdk_pixbuf_get_height(src);
+	s_has_alpha = gdk_pixbuf_get_has_alpha(src);
+	s_rowstride = gdk_pixbuf_get_rowstride(src);
+	s_pix = gdk_pixbuf_get_pixels(src);
+
+	g_return_val_if_fail(mask != NULL, NULL);
+
+	m_width = gdk_pixbuf_get_width(mask);
+	m_height = gdk_pixbuf_get_height(mask);
+	m_has_alpha = gdk_pixbuf_get_has_alpha(mask);
+	m_rowstride = gdk_pixbuf_get_rowstride(mask);
+	m_pix = gdk_pixbuf_get_pixels(mask);
+
+	g_return_val_if_fail(m_width <= s_width, NULL);
+	g_return_val_if_fail(m_height <= s_height, NULL);
+
+	d_width = m_width;
+	d_height = m_height;
+	dest = gdk_pixbuf_new(GDK_COLORSPACE_RGB, TRUE, 8, d_width, d_height);
+
+	g_return_val_if_fail(dest != NULL, NULL);
+
+	d_rowstride = gdk_pixbuf_get_rowstride(dest);
+	d_pix = gdk_pixbuf_get_pixels(dest);
+
+	pix_width = (m_has_alpha ? 4 : 3);
+
+
+
+	for (i = 0; i < m_height; i++) {
+		sp = s_pix + (i * s_rowstride);
+		dp = d_pix + (i * d_rowstride);
+		mp = m_pix + (i * m_rowstride);
+
+		for (j = 0; j < m_width; j++) {
+			*(dp++) = *(sp++);	/* red */
+			*(dp++) = *(sp++);	/* green */
+			*(dp++) = *(sp++);	/* blue */
+
+			if (s_has_alpha)
+			{
+				alpha = *(sp++);	/* alpha */
+			}
+			else
+			{
+				alpha = 0xff;
+			}
+
+			pix = PIXEL(mp, pix_width, j);
+			grey = GIMP_RGB_TO_GREY(pix->r, pix->g, pix->b);
+
+			*(dp++) = sqrt(alpha * (255 - grey));	/* alpha */
+		}
+	}
+
+	return dest;
+}

ext/morandi_native/morandi_native.c

@@ -69,6 +69,8 @@ PixbufUtils_CLASS_gamma(VALUE self OPTIONAL_ATTR, VALUE __v_src OPTIONAL_ATTR, V
 static VALUE
 PixbufUtils_CLASS_tint(int __p_argc, VALUE *__p_argv, VALUE self);
 
+static VALUE
+PixbufUtils_CLASS_mask(VALUE self OPTIONAL_ATTR, VALUE __v_src OPTIONAL_ATTR, VALUE __v_mask OPTIONAL_ATTR);
 
 /* Inline C code */
 
@@ -89,6 +91,7 @@ extern void Init_morandi_c(void);
 
 #include "rotate.h"
 #include "gamma.h"
+#include "mask.h"
 #include "tint.h"
 #include "filter.h"
 
@@ -1081,6 +1084,7 @@ Init_morandi_native(void) {
     rb_define_singleton_method(mPixbufUtils, "rotate", PixbufUtils_CLASS_rotate, 2);
     rb_define_singleton_method(mPixbufUtils, "gamma", PixbufUtils_CLASS_gamma, 2);
     rb_define_singleton_method(mPixbufUtils, "tint", PixbufUtils_CLASS_tint, -1);
+    rb_define_singleton_method(mPixbufUtils, "mask", PixbufUtils_CLASS_mask, 2);