xps: Use Opacity attribute for setting constant alpha.

4 files changed, 42 insertions, 4 deletions

diff --git a/xps/muxps.h b/xps/muxps.h
index 8150996f..f135b875 100644
--- a/xps/muxps.h
+++ b/xps/muxps.h
@@ -256,6 +256,10 @@ struct xps_context_s
 	 */
 	int fill_rule;
 
+	/* Opacity attribute stack */
+	float opacity[64];
+	int opacity_top;
+
 	/* Current path being accumulated */
 	fz_path *path;
 	fz_text *text; /* ... or text, for clipping brushes */
diff --git a/xps/xpscolor.c b/xps/xpscolor.c
index 1858c687..37dee5fe 100644
--- a/xps/xpscolor.c
+++ b/xps/xpscolor.c
@@ -10,7 +10,7 @@ xps_set_color(xps_context *ctx, fz_colorspace *colorspace, float *samples)
 	ctx->colorspace = colorspace;
 	for (i = 0; i < colorspace->n; i++)
 		ctx->color[i] = samples[i + 1];
-	ctx->alpha = samples[0];
+	ctx->alpha = samples[0] * ctx->opacity[ctx->opacity_top];
 }
 
 static int unhex(int chr)
diff --git a/xps/xpsopacity.c b/xps/xpsopacity.c
index 047e213d..51a356e3 100644
--- a/xps/xpsopacity.c
+++ b/xps/xpsopacity.c
@@ -36,12 +36,36 @@ xps_begin_opacity(xps_context *ctx, fz_matrix ctm, char *base_uri, xps_resource
 	if (opacity_att)
 		opacity = atof(opacity_att);
 
+	if (opacity_mask_tag && !strcmp(xps_tag(opacity_mask_tag), "SolidColorBrush"))
+	{
+		char *scb_opacity_att = xps_att(opacity_mask_tag, "Opacity");
+		char *scb_color_att = xps_att(opacity_mask_tag, "Color");
+		if (scb_opacity_att)
+			opacity = opacity * atof(scb_opacity_att);
+		if (scb_color_att)
+		{
+			fz_colorspace *colorspace;
+			float samples[32];
+			xps_parse_color(ctx, base_uri, scb_color_att, &colorspace, samples);
+			opacity = opacity * samples[0];
+		}
+		opacity_mask_tag = NULL;
+	}
+
 	xps_bounds_in_user_space(ctx, &bbox);
 
-	ctx->dev->beginmask(ctx->dev->user, bbox, 0, fz_devicegray, &opacity);
+	if (ctx->opacity_top + 1 < nelem(ctx->opacity))
+	{
+		ctx->opacity[ctx->opacity_top + 1] = ctx->opacity[ctx->opacity_top] * opacity;
+		ctx->opacity_top++;
+	}
+
 	if (opacity_mask_tag)
+	{
+		ctx->dev->beginmask(ctx->dev->user, bbox, 0, NULL, NULL);
 		xps_parse_brush(ctx, ctm, base_uri, dict, opacity_mask_tag);
-	ctx->dev->endmask(ctx->dev->user);
+		ctx->dev->endmask(ctx->dev->user);
+	}
 }
 
 void
@@ -51,5 +75,12 @@ xps_end_opacity(xps_context *ctx, char *base_uri, xps_resource *dict,
 	if (!opacity_att && !opacity_mask_tag)
 		return;
 
-	ctx->dev->popclip(ctx->dev->user);
+	if (ctx->opacity_top > 0)
+		ctx->opacity_top--;
+
+	if (opacity_mask_tag)
+	{
+		if (strcmp(xps_tag(opacity_mask_tag), "SolidColorBrush"))
+			ctx->dev->popclip(ctx->dev->user);
+	}
 }
diff --git a/xps/xpspage.c b/xps/xpspage.c
index 32439f19..39731ef2 100644
--- a/xps/xpspage.c
+++ b/xps/xpspage.c
@@ -101,6 +101,9 @@ xps_parse_fixed_page(xps_context *ctx, fz_matrix ctm, xps_page *page)
 
 	dict = NULL;
 
+	ctx->opacity_top = 0;
+	ctx->opacity[0] = 1;
+
 	for (node = xps_down(page->root); node; node = xps_next(node))
 	{
 		if (!strcmp(xps_tag(node), "FixedPage.Resources") && xps_down(node))