Overprint support.

Introduce an fz_overprint bitmap (currently just a uint32_t,
but it'll grow to be an array of them if FZ_MAX_COLOR is
increased). Pointers to this are passed into all our
painting routines.

NULL means "Do what you've always done before, with no overprint".
non NULL, means that every set bit means "don't ever alter this
component".

We therefore set the overprint bitmap up according to the input
color/colorspace/colorparams before calling each routine.

1 files changed, 31 insertions, 11 deletions

diff --git a/source/fitz/draw-imp.h b/source/fitz/draw-imp.h
index 5c6fc7b8..8d1c3ef6 100644
--- a/source/fitz/draw-imp.h
+++ b/source/fitz/draw-imp.h
@@ -108,6 +108,24 @@ struct fz_aa_context_s
 	float min_line_width;
 };
 
+/* Overprint bitmap */
+
+typedef struct
+{
+	/* Bit i set -> never alter this color */
+	uint32_t mask[(FZ_MAX_COLORS+31)/32];
+} fz_overprint;
+
+static void inline fz_set_overprint(fz_overprint *op, int i)
+{
+	op->mask[i>>5] |= 1<<(i&31);
+}
+
+static int inline fz_overprint_component(const fz_overprint *op, int i)
+{
+	return ((op->mask[i>>5]>>(i & 31)) & 1) == 0;
+}
+
 /*
  * Scan converter
  */
@@ -121,7 +139,7 @@ typedef void (fz_rasterizer_insert_fn)(fz_context *ctx, fz_rasterizer *r, float
 typedef void (fz_rasterizer_insert_rect_fn)(fz_context *ctx, fz_rasterizer *r, float fx0, float fy0, float fx1, float fy1);
 typedef void (fz_rasterizer_gap_fn)(fz_context *ctx, fz_rasterizer *r);
 typedef fz_irect *(fz_rasterizer_bound_fn)(fz_context *ctx, const fz_rasterizer *r, fz_irect *bbox);
-typedef void (fz_rasterizer_fn)(fz_context *ctx, fz_rasterizer *r, int eofill, const fz_irect *clip, fz_pixmap *pix, unsigned char *colorbv);
+typedef void (fz_rasterizer_fn)(fz_context *ctx, fz_rasterizer *r, int eofill, const fz_irect *clip, fz_pixmap *pix, unsigned char *colorbv, fz_overprint *eop);
 typedef int (fz_rasterizer_is_rect_fn)(fz_context *ctx, fz_rasterizer *r);
 
 typedef struct
@@ -325,8 +343,10 @@ fz_rect *fz_scissor_rasterizer(fz_context *ctx, const fz_rasterizer *rast, fz_re
 	pix: The pixmap to fill into.
 
 	colorbv: The color components corresponding to the pixmap.
+
+	eop: effective overprint.
 */
-void fz_convert_rasterizer(fz_context *ctx, fz_rasterizer *r, int eofill, fz_pixmap *pix, unsigned char *colorbv);
+void fz_convert_rasterizer(fz_context *ctx, fz_rasterizer *r, int eofill, fz_pixmap *pix, unsigned char *colorbv, fz_overprint *eop);
 
 /*
 	fz_is_rect_rasterizer: Detect if the edges fed into a
@@ -411,17 +431,17 @@ fz_irect *fz_bound_path_accurate(fz_context *ctx, fz_irect *bbox, const fz_irect
  * Plotting functions.
  */
 
-typedef void (fz_solid_color_painter_t)(unsigned char * restrict dp, int n, int w, const unsigned char * restrict color, int da);
+typedef void (fz_solid_color_painter_t)(unsigned char * restrict dp, int n, int w, const unsigned char * restrict color, int da, const fz_overprint * restrict eop);
 
-typedef void (fz_span_painter_t)(unsigned char * restrict dp, int da, const unsigned char * restrict sp, int sa, int n, int w, int alpha);
-typedef void (fz_span_color_painter_t)(unsigned char * restrict dp, const unsigned char * restrict mp, int n, int w, const unsigned char * restrict color, int da);
+typedef void (fz_span_painter_t)(unsigned char * restrict dp, int da, const unsigned char * restrict sp, int sa, int n, int w, int alpha, const fz_overprint * restrict eop);
+typedef void (fz_span_color_painter_t)(unsigned char * restrict dp, const unsigned char * restrict mp, int n, int w, const unsigned char * restrict color, int da, const fz_overprint * restrict eop);
 
-fz_solid_color_painter_t *fz_get_solid_color_painter(int n, const unsigned char * restrict color, int da);
-fz_span_painter_t *fz_get_span_painter(int da, int sa, int n, int alpha);
-fz_span_color_painter_t *fz_get_span_color_painter(int n, int da, const unsigned char * restrict color);
+fz_solid_color_painter_t *fz_get_solid_color_painter(int n, const unsigned char * restrict color, int da, const fz_overprint * restrict eop);
+fz_span_painter_t *fz_get_span_painter(int da, int sa, int n, int alpha, const fz_overprint * restrict eop);
+fz_span_color_painter_t *fz_get_span_color_painter(int n, int da, const unsigned char * restrict color, const fz_overprint * restrict eop);
 
-void fz_paint_image(fz_pixmap * restrict dst, const fz_irect * restrict scissor, fz_pixmap * restrict shape, const fz_pixmap * restrict img, const fz_matrix * restrict ctm, int alpha, int lerp_allowed, int gridfit_as_tiled);
-void fz_paint_image_with_color(fz_pixmap * restrict dst, const fz_irect * restrict scissor, fz_pixmap *restrict shape, const fz_pixmap * restrict img, const fz_matrix * restrict ctm, const unsigned char * restrict colorbv, int lerp_allowed, int gridfit_as_tiled);
+void fz_paint_image(fz_pixmap * restrict dst, const fz_irect * restrict scissor, fz_pixmap * restrict shape, const fz_pixmap * restrict img, const fz_matrix * restrict ctm, int alpha, int lerp_allowed, int gridfit_as_tiled, const fz_overprint * restrict eop);
+void fz_paint_image_with_color(fz_pixmap * restrict dst, const fz_irect * restrict scissor, fz_pixmap *restrict shape, const fz_pixmap * restrict img, const fz_matrix * restrict ctm, const unsigned char * restrict colorbv, int lerp_allowed, int gridfit_as_tiled, const fz_overprint * restrict eop);
 
 void fz_paint_pixmap(fz_pixmap * restrict dst, const fz_pixmap * restrict src, int alpha);
 void fz_paint_pixmap_with_mask(fz_pixmap * restrict dst, const fz_pixmap * restrict src, const fz_pixmap * restrict msk);
@@ -429,6 +449,6 @@ void fz_paint_pixmap_with_bbox(fz_pixmap * restrict dst, const fz_pixmap * restr
 
 void fz_blend_pixmap(fz_context *ctx, fz_pixmap * restrict dst, fz_pixmap * restrict src, int alpha, int blendmode, int isolated, const fz_pixmap * restrict shape);
 
-void fz_paint_glyph(const unsigned char * restrict colorbv, fz_pixmap * restrict dst, unsigned char * restrict dp, const fz_glyph * restrict glyph, int w, int h, int skip_x, int skip_y);
+void fz_paint_glyph(const unsigned char * restrict colorbv, fz_pixmap * restrict dst, unsigned char * restrict dp, const fz_glyph * restrict glyph, int w, int h, int skip_x, int skip_y, const fz_overprint * restrict eop);
 
 #endif