Disable image interpolation with a hint.

Set the hint in mudraw when AA bits is set to 0.

4 files changed, 17 insertions, 15 deletions

diff --git a/source/fitz/draw-affine.c b/source/fitz/draw-affine.c
index 1a7e1c57..284ca8df 100644
--- a/source/fitz/draw-affine.c
+++ b/source/fitz/draw-affine.c
@@ -941,7 +941,7 @@ fz_gridfit_matrix(fz_matrix *m)
 /* Draw an image with an affine transform on destination */
 
 static void
-fz_paint_image_imp(fz_pixmap *dst, const fz_irect *scissor, fz_pixmap *shape, fz_pixmap *img, const fz_matrix *ctm, byte *color, int alpha)
+fz_paint_image_imp(fz_pixmap *dst, const fz_irect *scissor, fz_pixmap *shape, fz_pixmap *img, const fz_matrix *ctm, byte *color, int alpha, int lerp_allowed)
 {
 	byte *dp, *sp, *hp;
 	int u, v, fa, fb, fc, fd;
@@ -961,11 +961,11 @@ fz_paint_image_imp(fz_pixmap *dst, const fz_irect *scissor, fz_pixmap *shape, fz
 	dolerp = 0;
 	is_rectilinear = fz_is_rectilinear(&local_ctm);
 	if (!is_rectilinear)
-		dolerp = 1;
+		dolerp = lerp_allowed;
 	if (sqrtf(local_ctm.a * local_ctm.a + local_ctm.b * local_ctm.b) > img->w)
-		dolerp = 1;
+		dolerp = lerp_allowed;
 	if (sqrtf(local_ctm.c * local_ctm.c + local_ctm.d * local_ctm.d) > img->h)
-		dolerp = 1;
+		dolerp = lerp_allowed;
 
 	/* except when we shouldn't, at large magnifications */
 	if (!img->interpolate)
@@ -1084,15 +1084,15 @@ fz_paint_image_imp(fz_pixmap *dst, const fz_irect *scissor, fz_pixmap *shape, fz
 }
 
 void
-fz_paint_image_with_color(fz_pixmap *dst, const fz_irect *scissor, fz_pixmap *shape, fz_pixmap *img, const fz_matrix *ctm, byte *color)
+fz_paint_image_with_color(fz_pixmap *dst, const fz_irect *scissor, fz_pixmap *shape, fz_pixmap *img, const fz_matrix *ctm, byte *color, int lerp_allowed)
 {
 	assert(img->n == 1);
-	fz_paint_image_imp(dst, scissor, shape, img, ctm, color, 255);
+	fz_paint_image_imp(dst, scissor, shape, img, ctm, color, 255, lerp_allowed);
 }
 
 void
-fz_paint_image(fz_pixmap *dst, const fz_irect *scissor, fz_pixmap *shape, fz_pixmap *img, const fz_matrix *ctm, int alpha)
+fz_paint_image(fz_pixmap *dst, const fz_irect *scissor, fz_pixmap *shape, fz_pixmap *img, const fz_matrix *ctm, int alpha, int lerp_allowed)
 {
 	assert(dst->n == img->n || (dst->n == 4 && img->n == 2));
-	fz_paint_image_imp(dst, scissor, shape, img, ctm, NULL, alpha);
+	fz_paint_image_imp(dst, scissor, shape, img, ctm, NULL, alpha, lerp_allowed);
 }
diff --git a/source/fitz/draw-device.c b/source/fitz/draw-device.c
index bcd93edb..66c670ba 100644
--- a/source/fitz/draw-device.c
+++ b/source/fitz/draw-device.c
@@ -561,7 +561,7 @@ fz_draw_fill_text(fz_device *devp, fz_text *text, const fz_matrix *ctm,
 			else
 			{
 				fz_matrix mat = {pixmap->w, 0.0, 0.0, pixmap->h, x + pixmap->x, y + pixmap->y};
-				fz_paint_image(state->dest, &state->scissor, state->shape, pixmap, &mat, alpha * 255);
+				fz_paint_image(state->dest, &state->scissor, state->shape, pixmap, &mat, alpha * 255, !(devp->hints & FZ_DONT_INTERPOLATE_IMAGES));
 			}
 			fz_drop_glyph(dev->ctx, glyph);
 		}
@@ -1093,7 +1093,7 @@ fz_draw_fill_image(fz_device *devp, fz_image *image, const fz_matrix *ctm, float
 			pixmap = converted;
 		}
 
-		if (dx < pixmap->w && dy < pixmap->h)
+		if (dx < pixmap->w && dy < pixmap->h && !(devp->hints & FZ_DONT_INTERPOLATE_IMAGES))
 		{
 			int gridfit = alpha == 1.0f && !(dev->flags & FZ_DRAWDEV_FLAGS_TYPE3);
 			scaled = fz_transform_pixmap(dev, pixmap, &local_ctm, state->dest->x, state->dest->y, dx, dy, gridfit, &clip);
@@ -1126,7 +1126,7 @@ fz_draw_fill_image(fz_device *devp, fz_image *image, const fz_matrix *ctm, float
 			}
 		}
 
-		fz_paint_image(state->dest, &state->scissor, state->shape, pixmap, &local_ctm, alpha * 255);
+		fz_paint_image(state->dest, &state->scissor, state->shape, pixmap, &local_ctm, alpha * 255, !(devp->hints & FZ_DONT_INTERPOLATE_IMAGES));
 
 		if (state->blendmode & FZ_BLEND_KNOCKOUT)
 			fz_knockout_end(dev);
@@ -1198,7 +1198,7 @@ fz_draw_fill_image_mask(fz_device *devp, fz_image *image, const fz_matrix *ctm,
 			colorbv[i] = colorfv[i] * 255;
 		colorbv[i] = alpha * 255;
 
-		fz_paint_image_with_color(state->dest, &state->scissor, state->shape, pixmap, &local_ctm, colorbv);
+		fz_paint_image_with_color(state->dest, &state->scissor, state->shape, pixmap, &local_ctm, colorbv, !(devp->hints & FZ_DONT_INTERPOLATE_IMAGES));
 
 		if (scaled)
 			fz_drop_pixmap(dev->ctx, scaled);
@@ -1304,7 +1304,7 @@ fz_draw_clip_image_mask(fz_device *devp, fz_image *image, const fz_rect *rect, c
 			if (scaled)
 				pixmap = scaled;
 		}
-		fz_paint_image(mask, &bbox, state->shape, pixmap, &local_ctm, 255);
+		fz_paint_image(mask, &bbox, state->shape, pixmap, &local_ctm, 255, !(devp->hints & FZ_DONT_INTERPOLATE_IMAGES));
 	}
 	fz_always(ctx)
 	{
diff --git a/source/fitz/draw-imp.h b/source/fitz/draw-imp.h
index 82823519..9b9e50c0 100644
--- a/source/fitz/draw-imp.h
+++ b/source/fitz/draw-imp.h
@@ -34,8 +34,8 @@ void fz_paint_solid_color(unsigned char * restrict dp, int n, int w, unsigned ch
 void fz_paint_span(unsigned char * restrict dp, unsigned char * restrict sp, int n, int w, int alpha);
 void fz_paint_span_with_color(unsigned char * restrict dp, unsigned char * restrict mp, int n, int w, unsigned char *color);
 
-void fz_paint_image(fz_pixmap *dst, const fz_irect *scissor, fz_pixmap *shape, fz_pixmap *img, const fz_matrix *ctm, int alpha);
-void fz_paint_image_with_color(fz_pixmap *dst, const fz_irect *scissor, fz_pixmap *shape, fz_pixmap *img, const fz_matrix *ctm, unsigned char *colorbv);
+void fz_paint_image(fz_pixmap *dst, const fz_irect *scissor, fz_pixmap *shape, fz_pixmap *img, const fz_matrix *ctm, int alpha, int lerp_allowed);
+void fz_paint_image_with_color(fz_pixmap *dst, const fz_irect *scissor, fz_pixmap *shape, fz_pixmap *img, const fz_matrix *ctm, unsigned char *colorbv, int lerp_allowed);
 
 void fz_paint_pixmap(fz_pixmap *dst, fz_pixmap *src, int alpha);
 void fz_paint_pixmap_with_mask(fz_pixmap *dst, fz_pixmap *src, fz_pixmap *msk);
diff --git a/source/tools/mudraw.c b/source/tools/mudraw.c
index c95be5e3..27f32f99 100644
--- a/source/tools/mudraw.c
+++ b/source/tools/mudraw.c
@@ -700,6 +700,8 @@ static void drawpage(fz_context *ctx, fz_document *doc, int pagenum)
 					fz_clear_pixmap_with_value(ctx, pix, 255);
 
 				dev = fz_new_draw_device(ctx, pix);
+				if (alphabits == 0)
+					fz_enable_device_hints(dev, FZ_DONT_INTERPOLATE_IMAGES);
 				if (list)
 					fz_run_display_list(list, dev, &ctm, &tbounds, &cookie);
 				else