Clarify scissor argument to clip device functions.

The scissor argument is an optional (potentially NULL) rectangle
that can give hints to devices about the area that can be scissored.
This is used by the draw device and display list device to minimize
the size of temporary clip mask buffers.

The scissor rectangle, if used, must have been transformed by the
current transform matrix.

6 files changed, 51 insertions, 45 deletions

diff --git a/source/fitz/bbox-device.c b/source/fitz/bbox-device.c
index e7ef249c..4fd8e7f9 100644
--- a/source/fitz/bbox-device.c
+++ b/source/fitz/bbox-device.c
@@ -88,14 +88,14 @@ fz_bbox_fill_image_mask(fz_context *ctx, fz_device *dev, fz_image *image, const
 }
 
 static void
-fz_bbox_clip_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz_rect *rect, int even_odd, const fz_matrix *ctm)
+fz_bbox_clip_path(fz_context *ctx, fz_device *dev, const fz_path *path, int even_odd, const fz_matrix *ctm, const fz_rect *scissor)
 {
 	fz_rect r;
 	fz_bbox_add_rect(ctx, dev, fz_bound_path(ctx, path, NULL, ctm, &r), 1);
 }
 
 static void
-fz_bbox_clip_stroke_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz_rect *rect, const fz_stroke_state *stroke, const fz_matrix *ctm)
+fz_bbox_clip_stroke_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz_stroke_state *stroke, const fz_matrix *ctm, const fz_rect *scissor)
 {
 	fz_rect r;
 	fz_bbox_add_rect(ctx, dev, fz_bound_path(ctx, path, stroke, ctm, &r), 1);
@@ -116,7 +116,7 @@ fz_bbox_clip_stroke_text(fz_context *ctx, fz_device *dev, const fz_text *text, c
 }
 
 static void
-fz_bbox_clip_image_mask(fz_context *ctx, fz_device *dev, fz_image *image, const fz_rect *rect, const fz_matrix *ctm)
+fz_bbox_clip_image_mask(fz_context *ctx, fz_device *dev, fz_image *image, const fz_matrix *ctm, const fz_rect *scissor)
 {
 	fz_rect r = fz_unit_rect;
 	fz_bbox_add_rect(ctx, dev, fz_transform_rect(&r, ctm), 1);
diff --git a/source/fitz/device.c b/source/fitz/device.c
index 1926cc16..d9dffc5d 100644
--- a/source/fitz/device.c
+++ b/source/fitz/device.c
@@ -94,7 +94,7 @@ fz_stroke_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz_st
 }
 
 void
-fz_clip_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz_rect *rect, int even_odd, const fz_matrix *ctm)
+fz_clip_path(fz_context *ctx, fz_device *dev, const fz_path *path, int even_odd, const fz_matrix *ctm, const fz_rect *scissor)
 {
 	if (dev->error_depth)
 	{
@@ -106,17 +106,17 @@ fz_clip_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz_rect
 	{
 		if (dev->hints & FZ_MAINTAIN_CONTAINER_STACK)
 		{
-			if (rect == NULL)
+			if (scissor == NULL)
 			{
 				fz_rect bbox;
 				fz_bound_path(ctx, path, NULL, ctm, &bbox);
 				push_clip_stack(ctx, dev, &bbox, fz_device_container_stack_is_clip_path);
 			}
 			else
-				push_clip_stack(ctx, dev, rect, fz_device_container_stack_is_clip_path);
+				push_clip_stack(ctx, dev, scissor, fz_device_container_stack_is_clip_path);
 		}
 		if (dev->clip_path)
-			dev->clip_path(ctx, dev, path, rect, even_odd, ctm);
+			dev->clip_path(ctx, dev, path, even_odd, ctm, scissor);
 	}
 	fz_catch(ctx)
 	{
@@ -127,7 +127,7 @@ fz_clip_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz_rect
 }
 
 void
-fz_clip_stroke_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz_rect *rect, const fz_stroke_state *stroke, const fz_matrix *ctm)
+fz_clip_stroke_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz_stroke_state *stroke, const fz_matrix *ctm, const fz_rect *scissor)
 {
 	if (dev->error_depth)
 	{
@@ -139,17 +139,17 @@ fz_clip_stroke_path(fz_context *ctx, fz_device *dev, const fz_path *path, const
 	{
 		if (dev->hints & FZ_MAINTAIN_CONTAINER_STACK)
 		{
-			if (rect == NULL)
+			if (scissor == NULL)
 			{
 				fz_rect bbox;
 				fz_bound_path(ctx, path, stroke, ctm, &bbox);
 				push_clip_stack(ctx, dev, &bbox, fz_device_container_stack_is_clip_stroke_path);
 			}
 			else
-				push_clip_stack(ctx, dev, rect, fz_device_container_stack_is_clip_stroke_path);
+				push_clip_stack(ctx, dev, scissor, fz_device_container_stack_is_clip_stroke_path);
 		}
 		if (dev->clip_stroke_path)
-			dev->clip_stroke_path(ctx, dev, path, rect, stroke, ctm);
+			dev->clip_stroke_path(ctx, dev, path, stroke, ctm, scissor);
 	}
 	fz_catch(ctx)
 	{
@@ -289,7 +289,7 @@ fz_fill_image_mask(fz_context *ctx, fz_device *dev, fz_image *image, const fz_ma
 }
 
 void
-fz_clip_image_mask(fz_context *ctx, fz_device *dev, fz_image *image, const fz_rect *rect, const fz_matrix *ctm)
+fz_clip_image_mask(fz_context *ctx, fz_device *dev, fz_image *image, const fz_matrix *ctm, const fz_rect *scissor)
 {
 	if (dev->error_depth)
 	{
@@ -300,9 +300,18 @@ fz_clip_image_mask(fz_context *ctx, fz_device *dev, fz_image *image, const fz_re
 	fz_try(ctx)
 	{
 		if (dev->hints & FZ_MAINTAIN_CONTAINER_STACK)
-			push_clip_stack(ctx, dev, rect, fz_device_container_stack_is_clip_image_mask);
+		{
+			if (scissor == NULL)
+			{
+				fz_rect bbox = fz_unit_rect;
+				fz_transform_rect(&bbox, ctm);
+				push_clip_stack(ctx, dev, &bbox, fz_device_container_stack_is_clip_image_mask);
+			}
+			else
+				push_clip_stack(ctx, dev, scissor, fz_device_container_stack_is_clip_image_mask);
+		}
 		if (dev->clip_image_mask)
-			dev->clip_image_mask(ctx, dev, image, rect, ctm);
+			dev->clip_image_mask(ctx, dev, image, ctm, scissor);
 	}
 	fz_catch(ctx)
 	{
diff --git a/source/fitz/draw-device.c b/source/fitz/draw-device.c
index fead1b0a..978e81cc 100644
--- a/source/fitz/draw-device.c
+++ b/source/fitz/draw-device.c
@@ -382,7 +382,7 @@ fz_draw_stroke_path(fz_context *ctx, fz_device *devp, const fz_path *path, const
 }
 
 static void
-fz_draw_clip_path(fz_context *ctx, fz_device *devp, const fz_path *path, const fz_rect *rect, int even_odd, const fz_matrix *ctm)
+fz_draw_clip_path(fz_context *ctx, fz_device *devp, const fz_path *path, int even_odd, const fz_matrix *ctm, const fz_rect *scissor)
 {
 	fz_draw_device *dev = (fz_draw_device*)devp;
 	fz_gel *gel = dev->gel;
@@ -405,10 +405,10 @@ fz_draw_clip_path(fz_context *ctx, fz_device *devp, const fz_path *path, const f
 	model = state->dest->colorspace;
 
 	fz_intersect_irect(fz_bound_gel(ctx, gel, &bbox), &state->scissor);
-	if (rect)
+	if (scissor)
 	{
 		fz_irect bbox2;
-		fz_intersect_irect(&bbox, fz_irect_from_rect(&bbox2, rect));
+		fz_intersect_irect(&bbox, fz_irect_from_rect(&bbox2, scissor));
 	}
 
 	if (fz_is_empty_irect(&bbox) || fz_is_rect_gel(ctx, gel))
@@ -448,7 +448,7 @@ fz_draw_clip_path(fz_context *ctx, fz_device *devp, const fz_path *path, const f
 }
 
 static void
-fz_draw_clip_stroke_path(fz_context *ctx, fz_device *devp, const fz_path *path, const fz_rect *rect, const fz_stroke_state *stroke, const fz_matrix *ctm)
+fz_draw_clip_stroke_path(fz_context *ctx, fz_device *devp, const fz_path *path, const fz_stroke_state *stroke, const fz_matrix *ctm, const fz_rect *scissor)
 {
 	fz_draw_device *dev = (fz_draw_device*)devp;
 	fz_gel *gel = dev->gel;
@@ -477,10 +477,10 @@ fz_draw_clip_stroke_path(fz_context *ctx, fz_device *devp, const fz_path *path,
 	model = state->dest->colorspace;
 
 	fz_intersect_irect(fz_bound_gel(ctx, gel, &bbox), &state->scissor);
-	if (rect)
+	if (scissor)
 	{
 		fz_irect bbox2;
-		fz_intersect_irect(&bbox, fz_irect_from_rect(&bbox2, rect));
+		fz_intersect_irect(&bbox, fz_irect_from_rect(&bbox2, scissor));
 	}
 
 	fz_try(ctx)
@@ -1261,7 +1261,7 @@ fz_draw_fill_image_mask(fz_context *ctx, fz_device *devp, fz_image *image, const
 }
 
 static void
-fz_draw_clip_image_mask(fz_context *ctx, fz_device *devp, fz_image *image, const fz_rect *rect, const fz_matrix *ctm)
+fz_draw_clip_image_mask(fz_context *ctx, fz_device *devp, fz_image *image, const fz_matrix *ctm, const fz_rect *scissor)
 {
 	fz_draw_device *dev = (fz_draw_device*)devp;
 	fz_irect bbox;
@@ -1305,10 +1305,10 @@ fz_draw_clip_image_mask(fz_context *ctx, fz_device *devp, fz_image *image, const
 	urect = fz_unit_rect;
 	fz_irect_from_rect(&bbox, fz_transform_rect(&urect, &local_ctm));
 	fz_intersect_irect(&bbox, &state->scissor);
-	if (rect)
+	if (scissor)
 	{
 		fz_irect bbox2;
-		fz_intersect_irect(&bbox, fz_irect_from_rect(&bbox2, rect));
+		fz_intersect_irect(&bbox, fz_irect_from_rect(&bbox2, scissor));
 	}
 
 	dx = sqrtf(local_ctm.a * local_ctm.a + local_ctm.b * local_ctm.b);
diff --git a/source/fitz/list-device.c b/source/fitz/list-device.c
index c003c2a5..42485766 100644
--- a/source/fitz/list-device.c
+++ b/source/fitz/list-device.c
@@ -724,13 +724,13 @@ fz_list_stroke_path(fz_context *ctx, fz_device *dev, const fz_path *path, const
 }
 
 static void
-fz_list_clip_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz_rect *rect, int even_odd, const fz_matrix *ctm)
+fz_list_clip_path(fz_context *ctx, fz_device *dev, const fz_path *path, int even_odd, const fz_matrix *ctm, const fz_rect *scissor)
 {
 	fz_rect rect2;
 
 	fz_bound_path(ctx, path, NULL, ctm, &rect2);
-	if (rect)
-		fz_intersect_rect(&rect2, rect);
+	if (scissor)
+		fz_intersect_rect(&rect2, scissor);
 	fz_append_display_node(
 		ctx,
 		dev,
@@ -748,13 +748,13 @@ fz_list_clip_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz
 }
 
 static void
-fz_list_clip_stroke_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz_rect *rect, const fz_stroke_state *stroke, const fz_matrix *ctm)
+fz_list_clip_stroke_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz_stroke_state *stroke, const fz_matrix *ctm, const fz_rect *scissor)
 {
 	fz_rect rect2;
 
 	fz_bound_path(ctx, path, stroke, ctm, &rect2);
-	if (rect)
-		fz_intersect_rect(&rect2, rect);
+	if (scissor)
+		fz_intersect_rect(&rect2, scissor);
 	fz_append_display_node(
 		ctx,
 		dev,
@@ -1042,14 +1042,14 @@ fz_list_fill_image_mask(fz_context *ctx, fz_device *dev, fz_image *image, const
 }
 
 static void
-fz_list_clip_image_mask(fz_context *ctx, fz_device *dev, fz_image *image, const fz_rect *rect, const fz_matrix *ctm)
+fz_list_clip_image_mask(fz_context *ctx, fz_device *dev, fz_image *image, const fz_matrix *ctm, const fz_rect *scissor)
 {
 	fz_image *image2 = fz_keep_image(ctx, image);
 	fz_rect rect2 = fz_unit_rect;
 
 	fz_transform_rect(&rect2, ctm);
-	if (rect)
-		fz_intersect_rect(&rect2, rect);
+	if (scissor)
+		fz_intersect_rect(&rect2, scissor);
 	fz_try(ctx)
 	{
 		fz_append_display_node(
@@ -1671,10 +1671,10 @@ visible:
 				fz_stroke_path(ctx, dev, path, stroke, &trans_ctm, colorspace, color, alpha);
 				break;
 			case FZ_CMD_CLIP_PATH:
-				fz_clip_path(ctx, dev, path, &trans_rect, n.flags, &trans_ctm);
+				fz_clip_path(ctx, dev, path, n.flags, &trans_ctm, &trans_rect);
 				break;
 			case FZ_CMD_CLIP_STROKE_PATH:
-				fz_clip_stroke_path(ctx, dev, path, &trans_rect, stroke, &trans_ctm);
+				fz_clip_stroke_path(ctx, dev, path, stroke, &trans_ctm, &trans_rect);
 				break;
 			case FZ_CMD_FILL_TEXT:
 				fz_fill_text(ctx, dev, *(fz_text **)node, &trans_ctm, colorspace, color, alpha);
@@ -1705,7 +1705,7 @@ visible:
 				break;
 			case FZ_CMD_CLIP_IMAGE_MASK:
 				if ((dev->hints & FZ_IGNORE_IMAGE) == 0)
-					fz_clip_image_mask(ctx, dev, *(fz_image **)node, &trans_rect, &trans_ctm);
+					fz_clip_image_mask(ctx, dev, *(fz_image **)node, &trans_ctm, &trans_rect);
 				break;
 			case FZ_CMD_POP_CLIP:
 				fz_pop_clip(ctx, dev);
diff --git a/source/fitz/svg-device.c b/source/fitz/svg-device.c
index e98532f1..3295bf7e 100644
--- a/source/fitz/svg-device.c
+++ b/source/fitz/svg-device.c
@@ -517,7 +517,7 @@ svg_dev_stroke_path(fz_context *ctx, fz_device *dev, const fz_path *path, const
 }
 
 static void
-svg_dev_clip_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz_rect *rect, int even_odd, const fz_matrix *ctm)
+svg_dev_clip_path(fz_context *ctx, fz_device *dev, const fz_path *path, int even_odd, const fz_matrix *ctm, const fz_rect *scissor)
 {
 	svg_device *sdev = (svg_device*)dev;
 	fz_output *out;
@@ -537,7 +537,7 @@ svg_dev_clip_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz
 }
 
 static void
-svg_dev_clip_stroke_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz_rect *rect, const fz_stroke_state *stroke, const fz_matrix *ctm)
+svg_dev_clip_stroke_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz_stroke_state *stroke, const fz_matrix *ctm, const fz_rect *scissor)
 {
 	svg_device *sdev = (svg_device*)dev;
 
@@ -846,7 +846,7 @@ svg_dev_fill_image_mask(fz_context *ctx, fz_device *dev, fz_image *image, const
 }
 
 static void
-svg_dev_clip_image_mask(fz_context *ctx, fz_device *dev, fz_image *image, const fz_rect *rect, const fz_matrix *ctm)
+svg_dev_clip_image_mask(fz_context *ctx, fz_device *dev, fz_image *image, const fz_matrix *ctm, const fz_rect *scissor)
 {
 	svg_device *sdev = (svg_device*)dev;
 	fz_output *out;
diff --git a/source/fitz/trace-device.c b/source/fitz/trace-device.c
index d93906e0..4d1e5b9b 100644
--- a/source/fitz/trace-device.c
+++ b/source/fitz/trace-device.c
@@ -163,7 +163,7 @@ fz_trace_stroke_path(fz_context *ctx, fz_device *dev, const fz_path *path, const
 }
 
 static void
-fz_trace_clip_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz_rect *rect, int even_odd, const fz_matrix *ctm)
+fz_trace_clip_path(fz_context *ctx, fz_device *dev, const fz_path *path, int even_odd, const fz_matrix *ctm, const fz_rect *scissor)
 {
 	fz_output *out = ((fz_trace_device*)dev)->out;
 	fz_printf(ctx, out, "<clip_path");
@@ -172,16 +172,13 @@ fz_trace_clip_path(fz_context *ctx, fz_device *dev, const fz_path *path, const f
 	else
 		fz_printf(ctx, out, " winding=\"nonzero\"");
 	fz_trace_matrix(ctx, out, ctm);
-	if (rect)
-		fz_printf(ctx, out, " contentbbox=\"%g %g %g %g\">\n", rect->x0, rect->y0, rect->x1, rect->y1);
-	else
-		fz_printf(ctx, out, ">\n");
+	fz_printf(ctx, out, ">\n");
 	fz_trace_path(ctx, out, path);
 	fz_printf(ctx, out, "</clip_path>\n");
 }
 
 static void
-fz_trace_clip_stroke_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz_rect *rect, const fz_stroke_state *stroke, const fz_matrix *ctm)
+fz_trace_clip_stroke_path(fz_context *ctx, fz_device *dev, const fz_path *path, const fz_stroke_state *stroke, const fz_matrix *ctm, const fz_rect *scissor)
 {
 	fz_output *out = ((fz_trace_device*)dev)->out;
 	fz_printf(ctx, out, "<clip_stroke_path");
@@ -282,7 +279,7 @@ fz_trace_fill_image_mask(fz_context *ctx, fz_device *dev, fz_image *image, const
 }
 
 static void
-fz_trace_clip_image_mask(fz_context *ctx, fz_device *dev, fz_image *image, const fz_rect *rect, const fz_matrix *ctm)
+fz_trace_clip_image_mask(fz_context *ctx, fz_device *dev, fz_image *image, const fz_matrix *ctm, const fz_rect *scissor)
 {
 	fz_output *out = ((fz_trace_device*)dev)->out;
 	fz_printf(ctx, out, "<clip_image_mask");