Regularize band writer interface.

We have various functions that, for different image formats,
write a header, then a band, then (sometimes) a trailer.

Push them all through a single interface.

This change also fixes potential problems caused by the trailer
writing being an implicit destructor, which can cause problems
in cleanup code if the trailer writing throws an error.

1 files changed, 19 insertions, 60 deletions

diff --git a/source/tools/mudraw.c b/source/tools/mudraw.c
index 1b5300d9..4708516a 100644
--- a/source/tools/mudraw.c
+++ b/source/tools/mudraw.c
@@ -760,17 +760,11 @@ static void dodrawpage(fz_context *ctx, fz_page *page, fz_display_list *list, in
 		fz_irect ibounds;
 		fz_pixmap *pix = NULL;
 		int w, h;
-		fz_png_output_context *poc = NULL;
-		fz_ps_output_context *psoc = NULL;
-		fz_mono_pcl_output_context *pmcoc = NULL;
-		fz_color_pcl_output_context *pccoc = NULL;
+		fz_band_writer *bander = NULL;
 		fz_bitmap *bit = NULL;
 
 		fz_var(pix);
-		fz_var(poc);
-		fz_var(psoc);
-		fz_var(pmcoc);
-		fz_var(pccoc);
+		fz_var(bander);
 		fz_var(bit);
 
 		fz_bound_page(ctx, page, &bounds);
@@ -878,24 +872,26 @@ static void dodrawpage(fz_context *ctx, fz_page *page, fz_display_list *list, in
 			if (output)
 			{
 				if (output_format == OUT_PGM || output_format == OUT_PPM || output_format == OUT_PNM)
-					fz_write_pnm_header(ctx, out, pix->w, totalheight, pix->n, pix->alpha);
+					bander = fz_new_pnm_band_writer(ctx, out);
 				else if (output_format == OUT_PAM)
-					fz_write_pam_header(ctx, out, pix->w, totalheight, pix->n, pix->alpha);
+					bander = fz_new_pam_band_writer(ctx, out);
 				else if (output_format == OUT_PNG)
-					poc = fz_write_png_header(ctx, out, pix->w, totalheight, pix->n, pix->alpha);
+					bander = fz_new_png_band_writer(ctx, out);
 				else if (output_format == OUT_PBM)
-					fz_write_pbm_header(ctx, out, pix->w, totalheight);
+					bander = fz_new_pbm_band_writer(ctx, out);
 				else if (output_format == OUT_PKM)
-					fz_write_pkm_header(ctx, out, pix->w, totalheight);
+					bander = fz_new_pkm_band_writer(ctx, out);
 				else if (output_format == OUT_PS)
-					psoc = fz_write_ps_header(ctx, out, pix->w, totalheight, pix->n, pix->xres, pix->yres, ++output_pagenum);
+					bander = fz_new_ps_band_writer(ctx, out);
 				else if (output_format == OUT_PCL)
 				{
 					if (out_cs == CS_MONO)
-						pmcoc = fz_write_mono_pcl_header(ctx, out, pix->w, totalheight, pix->xres, pix->yres, ++output_pagenum, NULL);
+						bander = fz_new_mono_pcl_band_writer(ctx, out, NULL);
 					else
-						pccoc = fz_write_color_pcl_header(ctx, out, pix->w, totalheight, pix->n, pix->xres, pix->yres, ++output_pagenum, NULL);
+						bander = fz_new_color_pcl_band_writer(ctx, out, NULL);
 				}
+				if (bander)
+					fz_write_header(ctx, bander, pix->w, totalheight, pix->n, pix->alpha, pix->xres, pix->yres, ++output_pagenum);
 			}
 
 			for (band = 0; band < bands; band++)
@@ -915,43 +911,14 @@ static void dodrawpage(fz_context *ctx, fz_page *page, fz_display_list *list, in
 
 				if (output)
 				{
-					if (output_format == OUT_PGM || output_format == OUT_PPM || output_format == OUT_PNM)
-						fz_write_pnm_band(ctx, out, pix->w, totalheight, pix->n, pix->alpha, pix->stride, band * bandheight, drawheight, pix->samples);
-					else if (output_format == OUT_PAM)
-						fz_write_pam_band(ctx, out, pix->w, totalheight, pix->n, pix->alpha, pix->stride, band * bandheight, drawheight, pix->samples);
-					else if (output_format == OUT_PNG)
-						fz_write_png_band(ctx, out, poc, pix->stride, band * bandheight, drawheight, pix->samples);
+					if (bander)
+						fz_write_band(ctx, bander, bit ? bit->stride : pix->stride, band * bandheight, drawheight, bit ? bit->samples : pix->samples);
 					else if (output_format == OUT_PWG)
 						fz_write_pixmap_as_pwg(ctx, out, pix, NULL);
-					else if (output_format == OUT_PCL)
-					{
-						if (out_cs == CS_MONO)
-						{
-							fz_write_mono_pcl_band(ctx, out, pmcoc, bit);
-							fz_drop_bitmap(ctx, bit);
-							bit = NULL;
-						}
-						else
-							fz_write_color_pcl_band(ctx, out, pccoc, pix->w, totalheight, pix->n, pix->stride, band * bandheight, drawheight, pix->samples);
-					}
-					else if (output_format == OUT_PS)
-						fz_write_ps_band(ctx, out, psoc, pix->w, totalheight, pix->n, pix->stride, band * bandheight, drawheight, pix->samples);
-					else if (output_format == OUT_PBM)
-					{
-						fz_write_pbm_band(ctx, out, bit);
-						fz_drop_bitmap(ctx, bit);
-						bit = NULL;
-					}
-					else if (output_format == OUT_PKM)
-					{
-						fz_write_pkm_band(ctx, out, bit);
-						fz_drop_bitmap(ctx, bit);
-						bit = NULL;
-					}
 					else if (output_format == OUT_TGA)
-					{
 						fz_write_pixmap_as_tga(ctx, out, pix);
-					}
+					fz_drop_bitmap(ctx, bit);
+					bit = NULL;
 				}
 
 				if (num_workers > 0 && band + num_workers < bands)
@@ -982,21 +949,13 @@ static void dodrawpage(fz_context *ctx, fz_page *page, fz_display_list *list, in
 			/* Any page level trailers go here */
 			if (output)
 			{
-				if (output_format == OUT_PNG)
-					fz_write_png_trailer(ctx, out, poc);
-				if (output_format == OUT_PS)
-					fz_write_ps_trailer(ctx, out, psoc);
-				if (output_format == OUT_PCL)
-				{
-					if (out_cs == CS_MONO)
-						fz_write_mono_pcl_trailer(ctx, out, pmcoc);
-					else
-						fz_write_color_pcl_trailer(ctx, out, pccoc);
-				}
+				if (bander)
+					fz_write_trailer(ctx, bander);
 			}
 		}
 		fz_always(ctx)
 		{
+			fz_drop_band_writer(ctx, bander);
 			fz_drop_bitmap(ctx, bit);
 			bit = NULL;
 			if (num_workers > 0)