Add fz_new_png_from_pixmap

This accompanies the function formerly known as fz_image_as_png (now
renamed to fz_new_png_from_image).

3 files changed, 28 insertions, 10 deletions

diff --git a/source/fitz/pixmap.c b/source/fitz/pixmap.c
index 3c99d724..3f580c9e 100644
--- a/source/fitz/pixmap.c
+++ b/source/fitz/pixmap.c
@@ -804,24 +804,28 @@ fz_output_png_trailer(fz_output *out, fz_png_output_context *poc)
 	putchunk("IEND", block, 0, out);
 }
 
-
-fz_buffer *
-fz_image_as_png(fz_context *ctx, fz_image *image, int w, int h)
+/* We use an auxiliary function to do pixmap_as_png, as it can enable us to
+ * drop pix early in the case where we have to convert, potentially saving
+ * us having to have 2 copies of the pixmap and a buffer open at once. */
+static fz_buffer *
+png_from_pixmap(fz_context *ctx, fz_pixmap *pix, int drop)
 {
-	fz_pixmap *pix = fz_image_get_pixmap(ctx, image, image->w, image->h);
 	fz_buffer *buf = NULL;
 	fz_output *out;
+	fz_pixmap *pix2 = NULL;
 
 	fz_var(buf);
 	fz_var(out);
+	fz_var(pix2);
 
 	fz_try(ctx)
 	{
 		if (pix->colorspace && pix->colorspace != fz_device_gray(ctx) && pix->colorspace != fz_device_rgb(ctx))
 		{
-			fz_pixmap *pix2 = fz_new_pixmap(ctx, fz_device_rgb(ctx), pix->w, pix->h);
+			pix2 = fz_new_pixmap(ctx, fz_device_rgb(ctx), pix->w, pix->h);
 			fz_convert_pixmap(ctx, pix2, pix);
-			fz_drop_pixmap(ctx, pix);
+			if (drop)
+				fz_drop_pixmap(ctx, pix);
 			pix = pix2;
 		}
 		buf = fz_new_buffer(ctx, 1024);
@@ -830,8 +834,8 @@ fz_image_as_png(fz_context *ctx, fz_image *image, int w, int h)
 	}
 	fz_always(ctx)
 	{
+		fz_drop_pixmap(ctx, drop ? pix : pix2);
 		fz_close_output(out);
-		fz_drop_pixmap(ctx, pix);
 	}
 	fz_catch(ctx)
 	{
@@ -841,6 +845,20 @@ fz_image_as_png(fz_context *ctx, fz_image *image, int w, int h)
 	return buf;
 }
 
+fz_buffer *
+fz_new_png_from_image(fz_context *ctx, fz_image *image, int w, int h)
+{
+	fz_pixmap *pix = fz_image_get_pixmap(ctx, image, image->w, image->h);
+
+	return png_from_pixmap(ctx, pix, 1);
+}
+
+fz_buffer *
+fz_new_png_from_pixmap(fz_context *ctx, fz_pixmap *pix)
+{
+	return png_from_pixmap(ctx, pix, 0);
+}
+
 /*
  * Write pixmap to TGA file (with or without alpha channel)
  */
diff --git a/source/fitz/stext-output.c b/source/fitz/stext-output.c
index d3241131..6ed595fc 100644
--- a/source/fitz/stext-output.c
+++ b/source/fitz/stext-output.c
@@ -258,7 +258,7 @@ fz_print_text_page_html(fz_context *ctx, fz_output *out, fz_text_page *page)
 				break;
 			default:
 				{
-					fz_buffer *buf = fz_image_as_png(ctx, image->image, image->image->w, image->image->h);
+					fz_buffer *buf = fz_new_png_from_image(ctx, image->image, image->image->w, image->image->h);
 					fz_printf(out, "image/png;base64,");
 					send_data_base64(out, buf);
 					fz_drop_buffer(ctx, buf);
diff --git a/source/fitz/svg-device.c b/source/fitz/svg-device.c
index 11194abc..d76f14b3 100644
--- a/source/fitz/svg-device.c
+++ b/source/fitz/svg-device.c
@@ -700,7 +700,7 @@ svg_dev_fill_image(fz_device *dev, fz_image *image, const fz_matrix *ctm, float
 		break;
 	default:
 		{
-			fz_buffer *buf = fz_image_as_png(ctx, image, image->w, image->h);
+			fz_buffer *buf = fz_new_png_from_image(ctx, image, image->w, image->h);
 			fz_printf(out, "image/png;base64,");
 			send_data_base64(out, buf);
 			fz_drop_buffer(ctx, buf);
@@ -742,7 +742,7 @@ fz_colorspace *colorspace, float *color, float alpha)
 		break;
 	default:
 		{
-			fz_buffer *buf = fz_image_as_png(ctx, image, image->w, image->h);
+			fz_buffer *buf = fz_new_png_from_image(ctx, image, image->w, image->h);
 			fz_printf(out, "image/png;base64,");
 			send_data_base64(out, buf);
 			fz_drop_buffer(ctx, buf);