Transfer function support.

Just for SMask transfer functions for now.
ArtifexSoftware · Jan 16, 2024 · c7581a1 · c7581a1
1 parent e05c18f
commit c7581a1
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Showing 16 changed files with 128 additions and 44 deletions.
diff --git a/include/mupdf/fitz/device.h b/include/mupdf/fitz/device.h
@@ -316,7 +316,7 @@ struct fz_device
 	void (*pop_clip)(fz_context *, fz_device *);
 
 	void (*begin_mask)(fz_context *, fz_device *, fz_rect area, int luminosity, fz_colorspace *, const float *bc, fz_color_params );
-	void (*end_mask)(fz_context *, fz_device *);
+	void (*end_mask)(fz_context *, fz_device *, fz_function *fn);
 	void (*begin_group)(fz_context *, fz_device *, fz_rect area, fz_colorspace *cs, int isolated, int knockout, int blendmode, float alpha);
 	void (*end_group)(fz_context *, fz_device *);
 
@@ -361,6 +361,7 @@ void fz_fill_image_mask(fz_context *ctx, fz_device *dev, fz_image *image, fz_mat
 void fz_clip_image_mask(fz_context *ctx, fz_device *dev, fz_image *image, fz_matrix ctm, fz_rect scissor);
 void fz_begin_mask(fz_context *ctx, fz_device *dev, fz_rect area, int luminosity, fz_colorspace *colorspace, const float *bc, fz_color_params color_params);
 void fz_end_mask(fz_context *ctx, fz_device *dev);
+void fz_end_mask_tr(fz_context *ctx, fz_device *dev, fz_function *fn);
 void fz_begin_group(fz_context *ctx, fz_device *dev, fz_rect area, fz_colorspace *cs, int isolated, int knockout, int blendmode, float alpha);
 void fz_end_group(fz_context *ctx, fz_device *dev);
 void fz_begin_tile(fz_context *ctx, fz_device *dev, fz_rect area, fz_rect view, float xstep, float ystep, fz_matrix ctm);

diff --git a/include/mupdf/pdf/interpret.h b/include/mupdf/pdf/interpret.h
@@ -68,7 +68,7 @@ struct pdf_processor
 	void (*op_gs_BM)(fz_context *ctx, pdf_processor *proc, const char *blendmode);
 	void (*op_gs_ca)(fz_context *ctx, pdf_processor *proc, float alpha);
 	void (*op_gs_CA)(fz_context *ctx, pdf_processor *proc, float alpha);
-	void (*op_gs_SMask)(fz_context *ctx, pdf_processor *proc, pdf_obj *smask, float *bc, int luminosity);
+	void (*op_gs_SMask)(fz_context *ctx, pdf_processor *proc, pdf_obj *smask, float *bc, int luminosity, pdf_obj *tr);
 	void (*op_gs_end)(fz_context *ctx, pdf_processor *proc);
 
 	/* special graphics state */

diff --git a/source/fitz/bbox-device.c b/source/fitz/bbox-device.c
@@ -152,7 +152,7 @@ fz_bbox_begin_mask(fz_context *ctx, fz_device *dev, fz_rect rect, int luminosity
 }
 
 static void
-fz_bbox_end_mask(fz_context *ctx, fz_device *dev)
+fz_bbox_end_mask(fz_context *ctx, fz_device *dev, fz_function *tr)
 {
 	fz_bbox_device *bdev = (fz_bbox_device*)dev;
 	assert(bdev->ignore > 0);

diff --git a/source/fitz/device.c b/source/fitz/device.c
@@ -416,14 +416,14 @@ fz_begin_mask(fz_context *ctx, fz_device *dev, fz_rect area, int luminosity, fz_
 }
 
 void
-fz_end_mask(fz_context *ctx, fz_device *dev)
+fz_end_mask_tr(fz_context *ctx, fz_device *dev, fz_function *fn)
 {
 	pop_push_clip_stack(ctx, dev, fz_device_container_stack_is_mask, fz_device_container_stack_is_clip);
 
 	if (dev->end_mask)
 	{
 		fz_try(ctx)
-			dev->end_mask(ctx, dev);
+			dev->end_mask(ctx, dev, fn);
 		fz_catch(ctx)
 		{
 			fz_disable_device(ctx, dev);
@@ -432,6 +432,12 @@ fz_end_mask(fz_context *ctx, fz_device *dev)
 	}
 }
 
+void
+fz_end_mask(fz_context *ctx, fz_device *dev)
+{
+	fz_end_mask_tr(ctx, dev, NULL);
+}
+
 void
 fz_begin_group(fz_context *ctx, fz_device *dev, fz_rect area, fz_colorspace *cs, int isolated, int knockout, int blendmode, float alpha)
 {

diff --git a/source/fitz/draw-device.c b/source/fitz/draw-device.c
@@ -2275,7 +2275,31 @@ fz_draw_begin_mask(fz_context *ctx, fz_device *devp, fz_rect area, int luminosit
 }
 
 static void
-fz_draw_end_mask(fz_context *ctx, fz_device *devp)
+apply_transform_function_to_pixmap(fz_context *ctx, fz_pixmap *pix, fz_function *tr)
+{
+	int w, h;
+	ptrdiff_t stride;
+	uint8_t *s;
+
+	assert(pix && pix->n == 1);
+
+	s = pix->samples;
+	stride = pix->stride - pix->w;
+	for (h = pix->h; h > 0; h--)
+	{
+		for (w = pix->w; w > 0; w--)
+		{
+			float f = *s / 255.0f;
+			float d;
+			fz_eval_function(ctx, tr, &f, 1, &d, 1);
+			*s++ = (uint8_t)fz_clampi(d*255.0f, 0, 255);
+		}
+		s += stride;
+	}
+}
+
+static void
+fz_draw_end_mask(fz_context *ctx, fz_device *devp, fz_function *tr)
 {
 	fz_draw_device *dev = (fz_draw_device*)devp;
 	fz_pixmap *temp, *dest;
@@ -2315,6 +2339,11 @@ fz_draw_end_mask(fz_context *ctx, fz_device *devp)
 		fz_dump_blend(ctx, "-> Clip ", temp);
 		printf("\n");
 #endif
+		if (tr)
+		{
+			/* Apply transfer function to state[1].mask */
+			apply_transform_function_to_pixmap(ctx, state[1].mask, tr);
+		}
 
 		/* create new dest scratch buffer */
 		bbox = fz_pixmap_bbox(ctx, temp);

diff --git a/source/fitz/list-device.c b/source/fitz/list-device.c
@@ -229,6 +229,7 @@ cmd_needs_alignment(fz_display_command cmd)
 		cmd == FZ_CMD_FILL_IMAGE ||
 		cmd == FZ_CMD_FILL_IMAGE_MASK ||
 		cmd == FZ_CMD_CLIP_IMAGE_MASK ||
+		cmd == FZ_CMD_END_MASK ||
 		cmd == FZ_CMD_DEFAULT_COLORSPACES);
 }
 
@@ -1153,22 +1154,30 @@ fz_list_begin_mask(fz_context *ctx, fz_device *dev, fz_rect rect, int luminosity
 }
 
 static void
-fz_list_end_mask(fz_context *ctx, fz_device *dev)
+fz_list_end_mask(fz_context *ctx, fz_device *dev, fz_function *tr)
 {
-	fz_append_display_node(
-		ctx,
-		dev,
-		FZ_CMD_END_MASK,
-		0, /* flags */
-		NULL, /* rect */
-		NULL, /* path */
-		NULL, /* color */
-		NULL, /* colorspace */
-		NULL, /* alpha */
-		NULL, /* ctm */
-		NULL, /* stroke */
-		NULL, /* private_data */
-		0); /* private_data_len */
+	fz_function *tr2 = fz_keep_function(ctx, tr);
+
+	fz_try(ctx)
+		fz_append_display_node(
+			ctx,
+			dev,
+			FZ_CMD_END_MASK,
+			0, /* flags */
+			NULL, /* rect */
+			NULL, /* path */
+			NULL, /* color */
+			NULL, /* colorspace */
+			NULL, /* alpha */
+			NULL, /* ctm */
+			NULL, /* stroke */
+			&tr2, /* private_data */
+			sizeof(tr2)); /* private_data_len */
+	fz_catch(ctx)
+	{
+		fz_drop_function(ctx, tr);
+		fz_rethrow(ctx);
+	}
 }
 
 static void
@@ -1636,6 +1645,10 @@ fz_drop_display_list_imp(fz_context *ctx, fz_storable *list_)
 			align_node_for_pointer(&node);
 			fz_drop_image(ctx, *(fz_image **)node);
 			break;
+		case FZ_CMD_END_MASK:
+			align_node_for_pointer(&node);
+			fz_drop_function(ctx, *(fz_function **)node);
+			break;
 		case FZ_CMD_DEFAULT_COLORSPACES:
 			align_node_for_pointer(&node);
 			fz_drop_default_colorspaces(ctx, *(fz_default_colorspaces **)node);
@@ -2001,7 +2014,8 @@ fz_run_display_list(fz_context *ctx, fz_display_list *list, fz_device *dev, fz_m
 				fz_begin_mask(ctx, dev, trans_rect, n.flags & 1, colorspace, color, color_params);
 				break;
 			case FZ_CMD_END_MASK:
-				fz_end_mask(ctx, dev);
+				align_node_for_pointer(&node);
+				fz_end_mask_tr(ctx, dev, *(fz_function **)node);
 				break;
 			case FZ_CMD_BEGIN_GROUP:
 				fz_begin_group(ctx, dev, trans_rect, colorspace, (n.flags & ISOLATED) != 0, (n.flags & KNOCKOUT) != 0, (n.flags>>2), alpha);

diff --git a/source/fitz/ocr-device.c b/source/fitz/ocr-device.c
@@ -286,12 +286,12 @@ fz_ocr_begin_mask(fz_context *ctx, fz_device *dev, fz_rect rect, int luminosity,
 }
 
 static void
-fz_ocr_end_mask(fz_context *ctx, fz_device *dev)
+fz_ocr_end_mask(fz_context *ctx, fz_device *dev, fz_function *tr)
 {
 	fz_ocr_device *ocr = (fz_ocr_device *)dev;
 
-	fz_end_mask(ctx, ocr->list_dev);
-	fz_end_mask(ctx, ocr->draw_dev);
+	fz_end_mask_tr(ctx, ocr->list_dev, tr);
+	fz_end_mask_tr(ctx, ocr->draw_dev, tr);
 }
 
 static void
@@ -852,11 +852,11 @@ rewrite_begin_mask(fz_context *ctx, fz_device *dev, fz_rect area, int luminosity
 }
 
 static void
-rewrite_end_mask(fz_context *ctx, fz_device *dev)
+rewrite_end_mask(fz_context *ctx, fz_device *dev, fz_function *tr)
 {
 	fz_rewrite_device *rewrite = (fz_rewrite_device *)dev;
 
-	fz_end_mask(ctx, rewrite->target);
+	fz_end_mask_tr(ctx, rewrite->target, tr);
 }
 
 static void

diff --git a/source/fitz/svg-device.c b/source/fitz/svg-device.c
@@ -1087,7 +1087,7 @@ svg_dev_begin_mask(fz_context *ctx, fz_device *dev, fz_rect bbox, int luminosity
 }
 
 static void
-svg_dev_end_mask(fz_context *ctx, fz_device *dev)
+svg_dev_end_mask(fz_context *ctx, fz_device *dev, fz_function *tr)
 {
 	svg_device *sdev = (svg_device*)dev;
 	fz_buffer *out = sdev->out;
@@ -1096,6 +1096,9 @@ svg_dev_end_mask(fz_context *ctx, fz_device *dev)
 	if (dev->container_len > 0)
 		mask = dev->container[dev->container_len-1].user;
 
+	if (tr)
+		fz_warn(ctx, "Ignoring Transfer Function");
+
 	fz_append_printf(ctx, out, "\"/>\n</mask>\n");
 	out = end_def(ctx, sdev, 0);
 	fz_append_printf(ctx, out, "<g mask=\"url(#mask_%d)\">\n", mask);

diff --git a/source/fitz/test-device.c b/source/fitz/test-device.c
@@ -467,12 +467,12 @@ fz_test_begin_mask(fz_context *ctx, fz_device *dev_, fz_rect rect, int luminosit
 }
 
 static void
-fz_test_end_mask(fz_context *ctx, fz_device *dev_)
+fz_test_end_mask(fz_context *ctx, fz_device *dev_, fz_function *tr)
 {
 	fz_test_device *dev = (fz_test_device*)dev_;
 
 	if (dev->passthrough)
-		fz_end_mask(ctx, dev->passthrough);
+		fz_end_mask_tr(ctx, dev->passthrough, tr);
 }
 
 static void

diff --git a/source/fitz/trace-device.c b/source/fitz/trace-device.c
@@ -488,13 +488,13 @@ fz_trace_begin_mask(fz_context *ctx, fz_device *dev_, fz_rect bbox, int luminosi
 }
 
 static void
-fz_trace_end_mask(fz_context *ctx, fz_device *dev_)
+fz_trace_end_mask(fz_context *ctx, fz_device *dev_, fz_function *tr)
 {
 	fz_trace_device *dev = (fz_trace_device*)dev_;
 	fz_output *out = dev->out;
 	dev->depth--;
 	fz_trace_indent(ctx, out, dev->depth);
-	fz_write_printf(ctx, out, "</clip_mask>\n");
+	fz_write_printf(ctx, out, "</clip_mask%s>\n", tr ? " (with TR)" : "");
 	dev->depth++;
 }
 

diff --git a/source/pdf/pdf-device.c b/source/pdf/pdf-device.c
@@ -1069,13 +1069,16 @@ pdf_dev_begin_mask(fz_context *ctx, fz_device *dev, fz_rect bbox, int luminosity
 }
 
 static void
-pdf_dev_end_mask(fz_context *ctx, fz_device *dev)
+pdf_dev_end_mask(fz_context *ctx, fz_device *dev, fz_function *tr)
 {
 	pdf_device *pdev = (pdf_device*)dev;
 	pdf_document *doc = pdev->doc;
 	gstate *gs = CURRENT_GSTATE(pdev);
 	pdf_obj *form_ref = (pdf_obj *)gs->on_pop_arg;
 
+	if (tr)
+		fz_warn(ctx, "Ignoring Transfer function");
+
 	/* Here we do part of the pop, but not all of it. */
 	pdf_dev_end_text(ctx, pdev);
 	fz_append_string(ctx, gs->buf, "Q\n");

diff --git a/source/pdf/pdf-interpret.c b/source/pdf/pdf-interpret.c
@@ -338,14 +338,14 @@ pdf_process_extgstate(fz_context *ctx, pdf_processor *proc, pdf_csi *csi, pdf_ob
 				luminosity = 0;
 
 			tr = pdf_dict_get(ctx, obj, PDF_NAME(TR));
-			if (tr && !pdf_name_eq(ctx, tr, PDF_NAME(Identity)))
-				fz_warn(ctx, "ignoring transfer function");
+			if (tr && pdf_name_eq(ctx, tr, PDF_NAME(Identity)))
+				tr = NULL;
 
-			proc->op_gs_SMask(ctx, proc, xobj, softmask_bc, luminosity);
+			proc->op_gs_SMask(ctx, proc, xobj, softmask_bc, luminosity, tr);
 		}
 		else if (pdf_is_name(ctx, obj) && pdf_name_eq(ctx, obj, PDF_NAME(None)))
 		{
-			proc->op_gs_SMask(ctx, proc, NULL, NULL, 0);
+			proc->op_gs_SMask(ctx, proc, NULL, NULL, 0, NULL);
 		}
 	}
 }

diff --git a/source/pdf/pdf-op-color.c b/source/pdf/pdf-op-color.c
@@ -584,12 +584,12 @@ pdf_color_gs_ca(fz_context *ctx, pdf_processor *proc, float alpha)
 }
 
 static void
-pdf_color_gs_SMask(fz_context *ctx, pdf_processor *proc, pdf_obj *smask, float *bc, int luminosity)
+pdf_color_gs_SMask(fz_context *ctx, pdf_processor *proc, pdf_obj *smask, float *bc, int luminosity, pdf_obj *tr)
 {
 	pdf_color_processor *p = (pdf_color_processor*)proc;
 
 	if (p->chain->op_gs_SMask)
-		p->chain->op_gs_SMask(ctx, p->chain, smask, bc, luminosity);
+		p->chain->op_gs_SMask(ctx, p->chain, smask, bc, luminosity, tr);
 }
 
 static void

diff --git a/source/pdf/pdf-op-filter.c b/source/pdf/pdf-op-filter.c
@@ -1186,15 +1186,15 @@ pdf_filter_gs_ca(fz_context *ctx, pdf_processor *proc, float alpha)
 }
 
 static void
-pdf_filter_gs_SMask(fz_context *ctx, pdf_processor *proc, pdf_obj *smask, float *bc, int luminosity)
+pdf_filter_gs_SMask(fz_context *ctx, pdf_processor *proc, pdf_obj *smask, float *bc, int luminosity, pdf_obj *tr)
 {
 	pdf_sanitize_processor *p = (pdf_sanitize_processor*)proc;
 
 	if (p->gstate->empty_clip_region)
 		return;
 
 	if (p->chain->op_gs_SMask)
-		p->chain->op_gs_SMask(ctx, p->chain, smask, bc, luminosity);
+		p->chain->op_gs_SMask(ctx, p->chain, smask, bc, luminosity, tr);
 }
 
 static void