1 files changed, 102 insertions, 0 deletions
diff --git a/xps/xpsopacity.c b/xps/xpsopacity.c
new file mode 100644
index 00000000..bd845efb
--- /dev/null
+++ b/xps/xpsopacity.c
@@ -0,0 +1,102 @@
+/* Copyright (C) 2006-2010 Artifex Software, Inc.
+   All Rights Reserved.
+
+   This software is provided AS-IS with no warranty, either express or
+   implied.
+
+   This software is distributed under license and may not be copied, modified
+   or distributed except as expressly authorized under the terms of that
+   license.  Refer to licensing information at http://www.artifex.com/
+   or contact Artifex Software, Inc.,  7 Mt. Lassen  Drive - Suite A-134,
+   San Rafael, CA  94903, U.S.A., +1(415)492-9861, for further information.
+*/
+
+/* XPS interpreter - transparency support */
+
+#include "ghostxps.h"
+
+void
+xps_bounds_in_user_space(xps_context_t *ctx, gs_rect *ubox)
+{
+	gx_clip_path *clip_path;
+	gs_rect dbox;
+	int code;
+
+	code = gx_effective_clip_path(ctx->pgs, &clip_path);
+	if (code < 0)
+		gs_warn("gx_effective_clip_path failed");
+
+	dbox.p.x = fixed2float(clip_path->outer_box.p.x);
+	dbox.p.y = fixed2float(clip_path->outer_box.p.y);
+	dbox.q.x = fixed2float(clip_path->outer_box.q.x);
+	dbox.q.y = fixed2float(clip_path->outer_box.q.y);
+	gs_bbox_transform_inverse(&dbox, &ctm_only(ctx->pgs), ubox);
+}
+
+int
+xps_begin_opacity(xps_context_t *ctx, char *base_uri, xps_resource_t *dict,
+		char *opacity_att, xps_item_t *opacity_mask_tag)
+{
+	gs_transparency_group_params_t tgp;
+	gs_transparency_mask_params_t tmp;
+	gs_rect bbox;
+	float opacity;
+	int save;
+	int code;
+
+	if (!opacity_att && !opacity_mask_tag)
+		return 0;
+
+	opacity = 1.0;
+	if (opacity_att)
+		opacity = atof(opacity_att);
+	gs_setopacityalpha(ctx->pgs, opacity);
+
+	xps_bounds_in_user_space(ctx, &bbox);
+
+	if (opacity_mask_tag)
+	{
+		gs_trans_mask_params_init(&tmp, TRANSPARENCY_MASK_Luminosity);
+		gs_begin_transparency_mask(ctx->pgs, &tmp, &bbox, 0);
+
+		gs_gsave(ctx->pgs);
+
+		/* Need a path to fill/clip for the brush */
+		gs_moveto(ctx->pgs, bbox.p.x, bbox.p.y);
+		gs_lineto(ctx->pgs, bbox.p.x, bbox.q.y);
+		gs_lineto(ctx->pgs, bbox.q.x, bbox.q.y);
+		gs_lineto(ctx->pgs, bbox.q.x, bbox.p.y);
+		gs_closepath(ctx->pgs);
+
+		/* opacity-only mode: use alpha value as gray color to create luminosity mask */
+		save = ctx->opacity_only;
+		ctx->opacity_only = 1;
+
+		code = xps_parse_brush(ctx, base_uri, dict, opacity_mask_tag);
+		if (code)
+		{
+			gs_grestore(ctx->pgs);
+			gs_end_transparency_mask(ctx->pgs, TRANSPARENCY_CHANNEL_Opacity);
+			ctx->opacity_only = save;
+			return gs_rethrow(code, "cannot parse opacity mask brush");
+		}
+
+		gs_grestore(ctx->pgs);
+		gs_end_transparency_mask(ctx->pgs, TRANSPARENCY_CHANNEL_Opacity);
+		ctx->opacity_only = save;
+	}
+
+	gs_trans_group_params_init(&tgp);
+	gs_begin_transparency_group(ctx->pgs, &tgp, &bbox);
+
+	return 0;
+}
+
+void
+xps_end_opacity(xps_context_t *ctx, char *base_uri, xps_resource_t *dict,
+		char *opacity_att, xps_item_t *opacity_mask_tag)
+{
+	if (!opacity_att && !opacity_mask_tag)
+		return;
+	gs_end_transparency_group(ctx->pgs);
+}