Add generic pixmap document writer.

Allow mutool convert to output all image formats we can write.

Add sanity checks for pbm and pkm writers.

6 files changed, 155 insertions, 87 deletions

diff --git a/source/fitz/bitmap.c b/source/fitz/bitmap.c
index 9db6a1df..9780b1dd 100644
--- a/source/fitz/bitmap.c
+++ b/source/fitz/bitmap.c
@@ -326,21 +326,41 @@ pkm_write_header(fz_context *ctx, fz_band_writer *writer)
 void
 fz_write_bitmap_as_pbm(fz_context *ctx, fz_output *out, fz_bitmap *bitmap)
 {
-	fz_band_writer *writer = fz_new_pbm_band_writer(ctx, out);
+	fz_band_writer *writer;
 
-	fz_write_header(ctx, writer, bitmap->w, bitmap->h, 1, 0, 0, 0, 0);
-	fz_write_band(ctx, writer, bitmap->stride, bitmap->h, bitmap->samples);
-	fz_drop_band_writer(ctx, writer);
+	if (bitmap->n != 1)
+		fz_throw(ctx, FZ_ERROR_GENERIC, "bitmap must be monochrome to save as PBM");
+
+	writer = fz_new_pbm_band_writer(ctx, out);
+	fz_try(ctx)
+	{
+		fz_write_header(ctx, writer, bitmap->w, bitmap->h, 1, 0, 0, 0, 0);
+		fz_write_band(ctx, writer, bitmap->stride, bitmap->h, bitmap->samples);
+	}
+	fz_always(ctx)
+		fz_drop_band_writer(ctx, writer);
+	fz_catch(ctx)
+		fz_rethrow(ctx);
 }
 
 void
 fz_write_bitmap_as_pkm(fz_context *ctx, fz_output *out, fz_bitmap *bitmap)
 {
-	fz_band_writer *writer = fz_new_pkm_band_writer(ctx, out);
+	fz_band_writer *writer;
+
+	if (bitmap->n != 4)
+		fz_throw(ctx, FZ_ERROR_GENERIC, "bitmap must be CMYK to save as PKM");
 
-	fz_write_header(ctx, writer, bitmap->w, bitmap->h, 1, 0, 0, 0, 0);
-	fz_write_band(ctx, writer, bitmap->stride, bitmap->h, bitmap->samples);
-	fz_drop_band_writer(ctx, writer);
+	writer = fz_new_pkm_band_writer(ctx, out);
+	fz_try(ctx)
+	{
+		fz_write_header(ctx, writer, bitmap->w, bitmap->h, 4, 0, 0, 0, 0);
+		fz_write_band(ctx, writer, bitmap->stride, bitmap->h, bitmap->samples);
+	}
+	fz_always(ctx)
+		fz_drop_band_writer(ctx, writer);
+	fz_catch(ctx)
+		fz_rethrow(ctx);
 }
 
 static void
@@ -421,7 +441,7 @@ fz_band_writer *fz_new_pkm_band_writer(fz_context *ctx, fz_output *out)
 }
 
 void
-fz_save_bitmap_as_pbm(fz_context *ctx, fz_bitmap *bitmap, char *filename)
+fz_save_bitmap_as_pbm(fz_context *ctx, fz_bitmap *bitmap, const char *filename)
 {
 	fz_output *out = fz_new_output_with_path(ctx, filename, 0);
 	fz_try(ctx)
@@ -433,7 +453,7 @@ fz_save_bitmap_as_pbm(fz_context *ctx, fz_bitmap *bitmap, char *filename)
 }
 
 void
-fz_save_bitmap_as_pkm(fz_context *ctx, fz_bitmap *bitmap, char *filename)
+fz_save_bitmap_as_pkm(fz_context *ctx, fz_bitmap *bitmap, const char *filename)
 {
 	fz_output *out = fz_new_output_with_path(ctx, filename, 0);
 	fz_try(ctx)
@@ -444,6 +464,30 @@ fz_save_bitmap_as_pkm(fz_context *ctx, fz_bitmap *bitmap, char *filename)
 		fz_rethrow(ctx);
 }
 
+void
+fz_save_pixmap_as_pbm(fz_context *ctx, fz_pixmap *pixmap, const char *filename)
+{
+	fz_bitmap *bitmap = fz_new_bitmap_from_pixmap(ctx, pixmap, NULL);
+	fz_try(ctx)
+		fz_save_bitmap_as_pbm(ctx, bitmap, filename);
+	fz_always(ctx)
+		fz_drop_bitmap(ctx, bitmap);
+	fz_catch(ctx)
+		fz_rethrow(ctx);
+}
+
+void
+fz_save_pixmap_as_pkm(fz_context *ctx, fz_pixmap *pixmap, const char *filename)
+{
+	fz_bitmap *bitmap = fz_new_bitmap_from_pixmap(ctx, pixmap, NULL);
+	fz_try(ctx)
+		fz_save_bitmap_as_pkm(ctx, bitmap, filename);
+	fz_always(ctx)
+		fz_drop_bitmap(ctx, bitmap);
+	fz_catch(ctx)
+		fz_rethrow(ctx);
+}
+
 void fz_bitmap_details(fz_bitmap *bit, int *w, int *h, int *n, int *stride)
 {
 	if (!bit)
diff --git a/source/fitz/halftone.c b/source/fitz/halftone.c
index f0705790..58153fcf 100644
--- a/source/fitz/halftone.c
+++ b/source/fitz/halftone.c
@@ -528,7 +528,8 @@ fz_bitmap *fz_new_bitmap_from_pixmap_band(fz_context *ctx, fz_pixmap *pix, fz_ha
 	if (!pix)
 		return NULL;
 
-	assert(pix->alpha == 0);
+	if (pix->alpha != 0)
+		fz_throw(ctx, FZ_ERROR_GENERIC, "pixmap may not have alpha channel to convert to bitmap");
 
 	fz_var(ht_line);
 	fz_var(out);
@@ -544,7 +545,7 @@ fz_bitmap *fz_new_bitmap_from_pixmap_band(fz_context *ctx, fz_pixmap *pix, fz_ha
 		thresh = &do_threshold_4;
 		break;
 	default:
-		assert(!"Unsupported number of components");
+		fz_throw(ctx, FZ_ERROR_GENERIC, "pixmap must be grayscale or CMYK to convert to bitmap");
 		return NULL;
 	}
 
diff --git a/source/fitz/output-cbz.c b/source/fitz/output-cbz.c
index 43be16cb..7268a805 100644
--- a/source/fitz/output-cbz.c
+++ b/source/fitz/output-cbz.c
@@ -87,3 +87,82 @@ fz_new_cbz_writer(fz_context *ctx, const char *path, const char *options)
 
 	return (fz_document_writer*)wri;
 }
+
+/* generic image file output writer */
+
+typedef struct fz_pixmap_writer_s fz_pixmap_writer;
+
+struct fz_pixmap_writer_s
+{
+	fz_document_writer super;
+	fz_draw_options options;
+	fz_pixmap *pixmap;
+	void (*save)(fz_context *ctx, fz_pixmap *pix, const char *filename);
+	int count;
+	char *path;
+};
+
+static fz_device *
+pixmap_begin_page(fz_context *ctx, fz_document_writer *wri_, const fz_rect *mediabox)
+{
+	fz_pixmap_writer *wri = (fz_pixmap_writer*)wri_;
+	return fz_new_draw_device_with_options(ctx, &wri->options, mediabox, &wri->pixmap);
+}
+
+static void
+pixmap_end_page(fz_context *ctx, fz_document_writer *wri_, fz_device *dev)
+{
+	fz_pixmap_writer *wri = (fz_pixmap_writer*)wri_;
+	char path[PATH_MAX];
+
+	fz_close_device(ctx, dev);
+	fz_drop_device(ctx, dev);
+
+	wri->count += 1;
+
+	fz_format_output_path(ctx, path, sizeof path, wri->path, wri->count);
+	wri->save(ctx, wri->pixmap, path);
+	fz_drop_pixmap(ctx, wri->pixmap);
+	wri->pixmap = NULL;
+}
+
+static void
+pixmap_drop_writer(fz_context *ctx, fz_document_writer *wri_)
+{
+	fz_pixmap_writer *wri = (fz_pixmap_writer*)wri_;
+	fz_drop_pixmap(ctx, wri->pixmap);
+	fz_free(ctx, wri->path);
+}
+
+fz_document_writer *
+fz_new_pixmap_writer(fz_context *ctx, const char *path, const char *options,
+	const char *default_path, int n,
+	void (*save)(fz_context *ctx, fz_pixmap *pix, const char *filename))
+{
+	fz_pixmap_writer *wri;
+
+	wri = fz_malloc_struct(ctx, fz_pixmap_writer);
+	wri->super.begin_page = pixmap_begin_page;
+	wri->super.end_page = pixmap_end_page;
+	wri->super.drop_writer = pixmap_drop_writer;
+
+	fz_try(ctx)
+	{
+		fz_parse_draw_options(ctx, &wri->options, options);
+		wri->path = fz_strdup(ctx, path ? path : default_path);
+		wri->save = save;
+		switch (n)
+		{
+		case 1: wri->options.colorspace = fz_device_gray(ctx); break;
+		case 3: wri->options.colorspace = fz_device_rgb(ctx); break;
+		case 4: wri->options.colorspace = fz_device_cmyk(ctx); break;
+		}
+	}
+	fz_catch(ctx)
+	{
+		fz_free(ctx, wri);
+		fz_rethrow(ctx);
+	}
+
+	return (fz_document_writer*)wri;
+}
diff --git a/source/fitz/output-png.c b/source/fitz/output-png.c
index de5500c9..c8972b25 100644
--- a/source/fitz/output-png.c
+++ b/source/fitz/output-png.c
@@ -299,74 +299,3 @@ fz_new_buffer_from_pixmap_as_png(fz_context *ctx, fz_pixmap *pix)
 {
 	return png_from_pixmap(ctx, pix, 0);
 }
-
-/* PNG output writer */
-
-typedef struct fz_png_writer_s fz_png_writer;
-
-struct fz_png_writer_s
-{
-	fz_document_writer super;
-	fz_draw_options options;
-	fz_pixmap *pixmap;
-	int count;
-	char *path;
-};
-
-const char *fz_png_write_options_usage = "";
-
-static fz_device *
-png_begin_page(fz_context *ctx, fz_document_writer *wri_, const fz_rect *mediabox)
-{
-	fz_png_writer *wri = (fz_png_writer*)wri_;
-	return fz_new_draw_device_with_options(ctx, &wri->options, mediabox, &wri->pixmap);
-}
-
-static void
-png_end_page(fz_context *ctx, fz_document_writer *wri_, fz_device *dev)
-{
-	fz_png_writer *wri = (fz_png_writer*)wri_;
-	char path[PATH_MAX];
-
-	fz_close_device(ctx, dev);
-	fz_drop_device(ctx, dev);
-
-	wri->count += 1;
-
-	fz_format_output_path(ctx, path, sizeof path, wri->path, wri->count);
-	fz_save_pixmap_as_png(ctx, wri->pixmap, path);
-	fz_drop_pixmap(ctx, wri->pixmap);
-	wri->pixmap = NULL;
-}
-
-static void
-png_drop_writer(fz_context *ctx, fz_document_writer *wri_)
-{
-	fz_png_writer *wri = (fz_png_writer*)wri_;
-	fz_drop_pixmap(ctx, wri->pixmap);
-	fz_free(ctx, wri->path);
-}
-
-fz_document_writer *
-fz_new_png_writer(fz_context *ctx, const char *path, const char *options)
-{
-	fz_png_writer *wri;
-
-	wri = fz_malloc_struct(ctx, fz_png_writer);
-	wri->super.begin_page = png_begin_page;
-	wri->super.end_page = png_end_page;
-	wri->super.drop_writer = png_drop_writer;
-
-	fz_try(ctx)
-	{
-		fz_parse_draw_options(ctx, &wri->options, options);
-		wri->path = fz_strdup(ctx, path ? path : "out-%04d.png");
-	}
-	fz_catch(ctx)
-	{
-		fz_free(ctx, wri);
-		fz_rethrow(ctx);
-	}
-
-	return (fz_document_writer*)wri;
-}
diff --git a/source/fitz/output-pnm.c b/source/fitz/output-pnm.c
index dbc521b7..455a5358 100644
--- a/source/fitz/output-pnm.c
+++ b/source/fitz/output-pnm.c
@@ -129,7 +129,7 @@ fz_write_pixmap_as_pnm(fz_context *ctx, fz_output *out, fz_pixmap *pixmap)
 }
 
 void
-fz_save_pixmap_as_pnm(fz_context *ctx, fz_pixmap *pixmap, char *filename)
+fz_save_pixmap_as_pnm(fz_context *ctx, fz_pixmap *pixmap, const char *filename)
 {
 	fz_band_writer *writer = NULL;
 	fz_output *out = fz_new_output_with_path(ctx, filename, 0);
@@ -226,7 +226,7 @@ fz_write_pixmap_as_pam(fz_context *ctx, fz_output *out, fz_pixmap *pixmap)
 }
 
 void
-fz_save_pixmap_as_pam(fz_context *ctx, fz_pixmap *pixmap, char *filename)
+fz_save_pixmap_as_pam(fz_context *ctx, fz_pixmap *pixmap, const char *filename)
 {
 	fz_band_writer *writer = NULL;
 	fz_output *out = fz_new_output_with_path(ctx, filename, 0);
diff --git a/source/fitz/writer.c b/source/fitz/writer.c
index 6ef40ffb..3c53f633 100644
--- a/source/fitz/writer.c
+++ b/source/fitz/writer.c
@@ -65,11 +65,26 @@ fz_new_document_writer(fz_context *ctx, const char *path, const char *format, co
 	if (!fz_strcasecmp(format, "pdf"))
 		return fz_new_pdf_writer(ctx, path, options);
 #endif
-	if (!fz_strcasecmp(format, "png"))
-		return fz_new_png_writer(ctx, path, options);
 	if (!fz_strcasecmp(format, "svg"))
 		return fz_new_svg_writer(ctx, path, options);
 
+	if (!fz_strcasecmp(format, "png"))
+		return fz_new_pixmap_writer(ctx, path, options, "out-%04.png", 0, fz_save_pixmap_as_png);
+	if (!fz_strcasecmp(format, "tga"))
+		return fz_new_pixmap_writer(ctx, path, options, "out-%04.tga", 0, fz_save_pixmap_as_tga);
+	if (!fz_strcasecmp(format, "pam"))
+		return fz_new_pixmap_writer(ctx, path, options, "out-%04.pam", 0, fz_save_pixmap_as_pam);
+	if (!fz_strcasecmp(format, "pnm"))
+		return fz_new_pixmap_writer(ctx, path, options, "out-%04.pnm", 0, fz_save_pixmap_as_pnm);
+	if (!fz_strcasecmp(format, "pgm"))
+		return fz_new_pixmap_writer(ctx, path, options, "out-%04.pgm", 1, fz_save_pixmap_as_pnm);
+	if (!fz_strcasecmp(format, "ppm"))
+		return fz_new_pixmap_writer(ctx, path, options, "out-%04.ppm", 3, fz_save_pixmap_as_pnm);
+	if (!fz_strcasecmp(format, "pbm"))
+		return fz_new_pixmap_writer(ctx, path, options, "out-%04.pbm", 1, fz_save_pixmap_as_pbm);
+	if (!fz_strcasecmp(format, "pkm"))
+		return fz_new_pixmap_writer(ctx, path, options, "out-%04.pkm", 4, fz_save_pixmap_as_pkm);
+
 	fz_throw(ctx, FZ_ERROR_GENERIC, "unknown output document format: %s", format);
 }