Put RISC OS filetype content handlers in their own directory.

svn path=/trunk/netsurf/; revision=12336

7 files changed, 1611 insertions, 0 deletions

diff --git a/riscos/content-handlers/artworks.c b/riscos/content-handlers/artworks.c
new file mode 100644
index 000000000..a46a03010
--- /dev/null
+++ b/riscos/content-handlers/artworks.c
@@ -0,0 +1,485 @@
+/*
+ * Copyright 2005 Adrian Lees <adrianl@users.sourceforge.net>
+ *
+ * This file is part of NetSurf, http://www.netsurf-browser.org/
+ *
+ * NetSurf is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * NetSurf is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** \file
+ * Content for image/x-artworks (RISC OS implementation).
+ *
+ * Uses the ArtworksRenderer module
+ */
+
+#include "utils/config.h"
+#ifdef WITH_ARTWORKS
+
+#include <assert.h>
+#include <limits.h>
+#include <stdlib.h>
+#include "swis.h"
+#include "oslib/os.h"
+#include "oslib/wimp.h"
+#include "utils/config.h"
+#include "content/content_protected.h"
+#include "desktop/plotters.h"
+#include "riscos/content-handlers/artworks.h"
+#include "riscos/gui.h"
+#include "riscos/wimputils.h"
+#include "utils/log.h"
+#include "utils/messages.h"
+#include "utils/talloc.h"
+#include "utils/utils.h"
+
+#define AWRender_FileInitAddress 0x46080
+#define AWRender_RenderAddress   0x46081
+#define AWRender_DocBounds       0x46082
+#define AWRender_SendDefs        0x46083
+#define AWRender_ClaimVectors    0x46084
+#define AWRender_ReleaseVectors  0x46085
+#define AWRender_FindFirstFont   0x46086
+#define AWRender_FindNextFont    0x46087
+
+
+#define INITIAL_BLOCK_SIZE 0x1000
+
+typedef struct artworks_content {
+	struct content base;
+
+	int x0, y0, x1, y1;
+
+	void *render_routine;
+	void *render_workspace;
+
+	/* dynamically-resizable block required by
+	   ArtWorksRenderer rendering routine */
+
+	void *block;
+	size_t size;
+} artworks_content;
+
+struct awinfo_block {
+	int ditherx;
+	int dithery;
+	int clip_x0;
+	int clip_y0;
+	int clip_x1;
+	int clip_y1;
+	int print_lowx;
+	int print_lowy;
+	int print_handle;
+	int print_x1;
+	int print_y1;
+	int bgcolour;
+};
+
+
+/* Assembler routines for interfacing with the ArtworksRenderer module */
+
+extern os_error *awrender_init(const char **doc,
+		unsigned long *doc_size,
+		void *routine,
+		void *workspace);
+
+extern os_error *awrender_render(const char *doc,
+		const struct awinfo_block *info,
+		const os_trfm *trans,
+		const int *vdu_vars,
+		void **rsz_block,
+		size_t *rsz_size,
+		int wysiwyg_setting,
+		int output_dest,
+		size_t doc_size,
+		void *routine,
+		void *workspace);
+
+static nserror artworks_create(const content_handler *handler,
+		lwc_string *imime_type, const http_parameter *params,
+		llcache_handle *llcache, const char *fallback_charset,
+		bool quirks, struct content **c);
+static bool artworks_convert(struct content *c);
+static void artworks_destroy(struct content *c);
+static bool artworks_redraw(struct content *c, int x, int y,
+		int width, int height, const struct rect *clip,
+		float scale, colour background_colour,
+		bool repeat_x, bool repeat_y);
+static nserror artworks_clone(const struct content *old, struct content **newc);
+static content_type artworks_content_type(lwc_string *mime_type);
+
+static const content_handler artworks_content_handler = {
+	artworks_create,
+	NULL,
+	artworks_convert,
+	NULL,
+	artworks_destroy,
+	NULL,
+	NULL,
+	NULL,
+	artworks_redraw,
+	NULL,
+	NULL,
+	artworks_clone,
+	NULL,
+	artworks_content_type,
+	false
+};
+
+static const char *artworks_types[] = {
+	"image/x-artworks"
+};
+
+static lwc_string *artworks_mime_types[NOF_ELEMENTS(artworks_types)];
+
+nserror artworks_init(void)
+{
+	uint32_t i;
+	lwc_error lerror;
+	nserror error;
+
+	for (i = 0; i < NOF_ELEMENTS(artworks_mime_types); i++) {
+		lerror = lwc_intern_string(artworks_types[i],
+				strlen(artworks_types[i]),
+				&artworks_mime_types[i]);
+		if (lerror != lwc_error_ok) {
+			error = NSERROR_NOMEM;
+			goto error;
+		}
+
+		error = content_factory_register_handler(artworks_mime_types[i],
+				&artworks_content_handler);
+		if (error != NSERROR_OK)
+			goto error;
+	}
+
+	return NSERROR_OK;
+
+error:
+	artworks_fini();
+
+	return error;
+}
+
+void artworks_fini(void)
+{
+	uint32_t i;
+
+	for (i = 0; i < NOF_ELEMENTS(artworks_mime_types); i++) {
+		if (artworks_mime_types[i] != NULL)
+			lwc_string_unref(artworks_mime_types[i]);
+	}
+}
+
+nserror artworks_create(const content_handler *handler,
+		lwc_string *imime_type, const http_parameter *params,
+		llcache_handle *llcache, const char *fallback_charset,
+		bool quirks, struct content **c)
+{
+	artworks_content *aw;
+	nserror error;
+
+	aw = talloc_zero(0, artworks_content);
+	if (aw == NULL)
+		return NSERROR_NOMEM;
+
+	error = content__init(&aw->base, handler, imime_type, params,
+			llcache, fallback_charset, quirks);
+	if (error != NSERROR_OK) {
+		talloc_free(aw);
+		return error;
+	}
+
+	*c = (struct content *) aw;
+
+	return NSERROR_OK;
+}
+
+/**
+ * Convert a CONTENT_ARTWORKS for display.
+ *
+ * No conversion is necessary. We merely read the ArtWorks
+ * bounding box bottom-left.
+ */
+
+bool artworks_convert(struct content *c)
+{
+	artworks_content *aw = (artworks_content *) c;
+	union content_msg_data msg_data;
+	const char *source_data;
+	unsigned long source_size;
+	void *init_workspace;
+	void *init_routine;
+	os_error *error;
+	int used = -1;  /* slightly better with older OSLib versions */
+	char title[100];
+
+	/* check whether AWViewer has been seen and we can therefore
+		locate the ArtWorks rendering modules */
+	xos_read_var_val_size("Alias$LoadArtWorksModules", 0, os_VARTYPE_STRING,
+				&used, NULL, NULL);
+	if (used >= 0) {
+		LOG(("Alias$LoadArtWorksModules not defined"));
+		msg_data.error = messages_get("AWNotSeen");
+		content_broadcast(c, CONTENT_MSG_ERROR, msg_data);
+		return false;
+	}
+
+	/* load the modules, or do nothing if they're already loaded */
+	error = xos_cli("LoadArtWorksModules");
+	if (error) {
+		LOG(("xos_cli: 0x%x: %s",
+				error->errnum, error->errmess));
+		msg_data.error = error->errmess;
+		content_broadcast(c, CONTENT_MSG_ERROR, msg_data);
+		return false;
+	}
+
+	/* lookup the addresses of the init and render routines */
+	error = (os_error*)_swix(AWRender_FileInitAddress, _OUT(0) | _OUT(1),
+				&init_routine, &init_workspace);
+	if (error) {
+		LOG(("AWRender_FileInitAddress: 0x%x: %s",
+				error->errnum, error->errmess));
+		msg_data.error = error->errmess;
+		content_broadcast(c, CONTENT_MSG_ERROR, msg_data);
+		return false;
+	}
+
+	error = (os_error*)_swix(AWRender_RenderAddress, _OUT(0) | _OUT(1),
+				&aw->render_routine,
+				&aw->render_workspace);
+	if (error) {
+		LOG(("AWRender_RenderAddress: 0x%x: %s",
+				error->errnum, error->errmess));
+		msg_data.error = error->errmess;
+		content_broadcast(c, CONTENT_MSG_ERROR, msg_data);
+		return false;
+	}
+
+	source_data = content__get_source_data(c, &source_size);
+
+	/* initialise (convert file to new format if required) */
+	error = awrender_init(&source_data, &source_size,
+			init_routine, init_workspace);
+	if (error) {
+		LOG(("awrender_init: 0x%x : %s",
+			error->errnum, error->errmess));
+		msg_data.error = error->errmess;
+		content_broadcast(c, CONTENT_MSG_ERROR, msg_data);
+		return false;
+	}
+
+	error = (os_error*)_swix(AWRender_DocBounds, 
+			_IN(0) | _OUT(2) | _OUT(3) | _OUT(4) | _OUT(5),
+			source_data,
+			&aw->x0,
+			&aw->y0,
+			&aw->x1,
+			&aw->y1);
+
+	if (error) {
+		LOG(("AWRender_DocBounds: 0x%x: %s",
+			error->errnum, error->errmess));
+		msg_data.error = error->errmess;
+		content_broadcast(c, CONTENT_MSG_ERROR, msg_data);
+		return false;
+	}
+
+	LOG(("bounding box: %d,%d,%d,%d", aw->x0, aw->y0, aw->x1, aw->y1));
+
+	/* create the resizable workspace required by the
+		ArtWorksRenderer rendering routine */
+
+	aw->size = INITIAL_BLOCK_SIZE;
+	aw->block = malloc(INITIAL_BLOCK_SIZE);
+	if (!aw->block) {
+		LOG(("failed to create block for ArtworksRenderer"));
+		msg_data.error = messages_get("NoMemory");
+		content_broadcast(c, CONTENT_MSG_ERROR, msg_data);
+		return false;
+	}
+
+	c->width  = (aw->x1 - aw->x0) / 512;
+	c->height = (aw->y1 - aw->y0) / 512;
+
+	snprintf(title, sizeof(title), messages_get("ArtWorksTitle"), 
+			c->width, c->height, source_size);
+	content__set_title(c, title);
+	content_set_ready(c);
+	content_set_done(c);
+	/* Done: update status bar */
+	content_set_status(c, "");
+	return true;
+}
+
+
+/**
+ * Destroy a CONTENT_ARTWORKS and free all resources it owns.
+ */
+
+void artworks_destroy(struct content *c)
+{
+	artworks_content *aw = (artworks_content *) c;
+
+	free(aw->block);
+}
+
+
+/**
+ * Redraw a CONTENT_ARTWORKS.
+ */
+
+bool artworks_redraw(struct content *c, int x, int y,
+		int width, int height, const struct rect *clip,
+		float scale, colour background_colour,
+		bool repeat_x, bool repeat_y)
+{
+	static const ns_os_vdu_var_list vars = {
+		os_MODEVAR_XEIG_FACTOR,
+		{
+			os_MODEVAR_YEIG_FACTOR,
+			os_MODEVAR_LOG2_BPP,
+			os_VDUVAR_END_LIST
+		}
+	};
+	artworks_content *aw = (artworks_content *) c;
+	struct awinfo_block info;
+	const char *source_data;
+	unsigned long source_size;
+	os_error *error;
+	os_trfm matrix;
+	int vals[24];
+
+	int clip_x0 = clip->x0;
+	int clip_y0 = clip->y0;
+	int clip_x1 = clip->x1;
+	int clip_y1 = clip->y1;
+
+	if (plot.flush && !plot.flush())
+		return false;
+
+	/* pick up render addresses again in case they've changed
+	   (eg. newer AWRender module loaded since we first loaded this file) */
+	(void)_swix(AWRender_RenderAddress, _OUT(0) | _OUT(1),
+				&aw->render_routine,
+				&aw->render_workspace);
+
+	/* Scaled image. Transform units (65536*OS units) */
+	matrix.entries[0][0] = width * 65536 / c->width;
+	matrix.entries[0][1] = 0;
+	matrix.entries[1][0] = 0;
+	matrix.entries[1][1] = height * 65536 / c->height;
+	/* Draw units. (x,y) = bottom left */
+	matrix.entries[2][0] = ro_plot_origin_x * 256 + x * 512 -
+			aw->x0 * width / c->width;
+	matrix.entries[2][1] = ro_plot_origin_y * 256 - (y + height) * 512 -
+			aw->y0 * height / c->height;
+
+	info.ditherx = ro_plot_origin_x;
+	info.dithery = ro_plot_origin_y;
+
+	clip_x0 -= x;
+	clip_y0 -= y;
+	clip_x1 -= x;
+	clip_y1 -= y;
+
+	if (scale == 1.0) {
+		info.clip_x0 = (clip_x0 * 512) + aw->x0 - 511;
+		info.clip_y0 = ((c->height - clip_y1) * 512) + aw->y0 - 511;
+		info.clip_x1 = (clip_x1 * 512) + aw->x0 + 511;
+		info.clip_y1 = ((c->height - clip_y0) * 512) + aw->y0 + 511;
+	}
+	else {
+		info.clip_x0 = (clip_x0 * 512 / scale) + aw->x0 - 511;
+		info.clip_y0 = ((c->height - (clip_y1 / scale)) * 512) + aw->y0 - 511;
+		info.clip_x1 = (clip_x1 * 512 / scale) + aw->x0 + 511;
+		info.clip_y1 = ((c->height - (clip_y0 / scale)) * 512) + aw->y0 + 511;
+	}
+
+	info.print_lowx = 0;
+	info.print_lowy = 0;
+	info.print_handle = 0;
+	info.bgcolour = 0x20000000 | background_colour;
+
+	error = xos_read_vdu_variables(PTR_OS_VDU_VAR_LIST(&vars), vals);
+	if (error) {
+		LOG(("xos_read_vdu_variables: 0x%x: %s",
+			error->errnum, error->errmess));
+		return false;
+	}
+
+	error = xwimp_read_palette((os_palette*)&vals[3]);
+	if (error) {
+		LOG(("xwimp_read_palette: 0x%x: %s",
+			error->errnum, error->errmess));
+		return false;
+	}
+
+	source_data = content__get_source_data(c, &source_size);
+
+	error = awrender_render(source_data,
+			&info,
+			&matrix,
+			vals,
+			&aw->block,
+			&aw->size,
+			110,	/* fully anti-aliased */
+			0,
+			source_size,
+			aw->render_routine,
+			aw->render_workspace);
+
+	if (error) {
+		LOG(("awrender_render: 0x%x: %s",
+				error->errnum, error->errmess));
+		return false;
+	}
+
+	return true;
+}
+
+nserror artworks_clone(const struct content *old, struct content **newc)
+{
+	artworks_content *aw;
+	nserror error;
+
+	aw = talloc_zero(0, artworks_content);
+	if (aw == NULL)
+		return NSERROR_NOMEM;
+
+	error = content__clone(old, &aw->base);
+	if (error != NSERROR_OK) {
+		content_destroy(&aw->base);
+		return error;
+	}
+
+	/* Simply re-run convert */
+	if (old->status == CONTENT_STATUS_READY || 
+			old->status == CONTENT_STATUS_DONE) {
+		if (artworks_convert(&aw->base) == false) {
+			content_destroy(&aw->base);
+			return NSERROR_CLONE_FAILED;
+		}
+	}
+
+	*newc = (struct content *) aw;
+
+	return NSERROR_OK;
+}
+
+content_type artworks_content_type(lwc_string *mime_type)
+{
+	return CONTENT_IMAGE;
+}
+
+#endif
diff --git a/riscos/content-handlers/artworks.h b/riscos/content-handlers/artworks.h
new file mode 100644
index 000000000..4a339cc84
--- /dev/null
+++ b/riscos/content-handlers/artworks.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2005 Adrian Lees <adrianl@users.sourceforge.net>
+ *
+ * This file is part of NetSurf, http://www.netsurf-browser.org/
+ *
+ * NetSurf is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * NetSurf is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** \file
+ * Content for image/x-artworks (RISC OS interface).
+ */
+
+#ifndef _NETSURF_RISCOS_ARTWORKS_H_
+#define _NETSURF_RISCOS_ARTWORKS_H_
+
+#include "utils/config.h"
+#include "utils/errors.h"
+
+#ifdef WITH_ARTWORKS
+
+nserror artworks_init(void);
+void artworks_fini(void);
+
+#else
+
+#define artworks_init() NSERROR_OK
+#define artworks_fini() ((void) 0)
+
+#endif
+
+#endif
diff --git a/riscos/content-handlers/awrender.s b/riscos/content-handlers/awrender.s
new file mode 100644
index 000000000..5bcafe520
--- /dev/null
+++ b/riscos/content-handlers/awrender.s
@@ -0,0 +1,390 @@
+#if defined(__aof__)
+		AREA	|ARM$$code|,CODE,READONLY
+
+		IMPORT	messages_get
+		IMPORT	realloc
+		IMPORT	strcpy
+		IMPORT	|__rt_stkovf_split_big|
+
+		EXPORT	awrender_init
+		EXPORT	awrender_render
+
+
+aw_rsz_block	*	0
+aw_rsz_size	*	4
+aw_fixed_block	*	8
+aw_fixed_size	*	12
+aw_sl		*	16
+aw_fp		*	20
+sizeof_aw	*	24
+
+
+; os_error *awrender_init(byte **doc, size_t *doc_size, void *init_routine, void *init_workspace);
+
+awrender_init	MOV	ip,sp
+		STMFD	sp!,{a1,a2,v1,v2,fp,ip,lr,pc}
+		SUB	fp,ip,#4
+		SUB	ip,sp,#512
+		CMP	ip,sl
+		BLMI	|__rt_stkovf_split_big|
+
+		LDR	v2,=aw_temp
+		LDR	a1,[a1]
+		MOV	v1,a3
+		LDR	a3,[a2]
+		MOV	ip,a4
+		STR	a1,[v2,#aw_rsz_block]
+		STR	a3,[v2,#aw_rsz_size]
+		MOV	a2,#-1
+		STR	a2,[v2,#aw_fixed_block]
+		STR	a3,[v2,#aw_fixed_size]
+		STR	sl,[v2,#aw_sl]
+		STR	fp,[v2,#aw_fp]
+		ADR	a2,aw_callback
+		MOV	lr,pc
+		MOV	pc,v1
+		MOVVC	a1,#0
+
+		;return updated block ptr & size to caller
+
+		LDR	a2,[fp,#-28]
+		LDR	a3,[fp,#-24]
+		LDR	ip,[v2,#aw_rsz_block]
+		LDR	lr,[v2,#aw_rsz_size]
+		STR	ip,[a2]
+		STR	lr,[a3]
+
+		LDMEA	fp,{v1,v2,fp,sp,pc}
+
+
+; os_error *awrender_render(const char *doc,
+;		const struct awinfo_block *info,
+;		const os_trfm *trans,
+;		const int *vdu_vars,
+;		char **rsz_block,
+;		size_t *rsz_size,
+;		int wysiwyg_setting,
+;		int output_dest,
+;		size_t doc_size,
+;		void *routine,
+;		void *workspace);
+
+awrender_render	MOV	ip,sp
+		STMFD	sp!,{v1-v4,fp,ip,lr,pc}
+		SUB	fp,ip,#4
+		SUB	ip,sp,#512
+		CMP	ip,sl
+		BLMI	|__rt_stkovf_split_big|
+
+		LDR	R12,[fp,#20]
+		LDR	R14,=aw_temp
+		LDR	R5,[fp,#4]
+		LDR	R6,[fp,#12]
+		LDR	R4,[R5]				;resizable block
+		LDR	R7,[fp,#16]
+		STR	R4,[R14,#aw_rsz_block]
+		STR	R0,[R14,#aw_fixed_block]	;document ptr
+		STR	R12,[R14,#aw_fixed_size]	;document size
+		LDR	R12,[fp,#8]
+
+		STR	R5,[sp,#-4]!			;ptr to receive block
+		STR	R12,[sp,#-4]!			;ptr to receive size
+
+		LDR	R12,[R12]
+		ADR	R5,aw_callback
+		STR	R12,[R14,#aw_rsz_size]
+
+		STR	sl,[R14,#aw_sl]
+		STR	fp,[R14,#aw_fp]
+
+		LDR	R12,[fp,#28]
+		MOV	lr,pc
+		LDR	pc,[fp,#24]
+		MOVVC	a1,#0
+
+		;return updated block ptr & size to caller
+
+		LDR	R7,=aw_temp
+		LDR	R12,[sp],#4
+		LDR	R4,[sp],#4
+		LDR	R5,[R7,#aw_rsz_size]
+		LDR	R6,[R7,#aw_rsz_block]
+		STR	R5,[R12]
+		STR	R6,[R4]
+
+		LDMEA	fp,{v1-v4,fp,sp,pc}
+
+
+; Callback routine for block resizing
+; (passed to AWRender init and render routines)
+;
+; entry	R11 = reason code
+;		0 = CallBackReason_Memory
+;		3 = CallBackReason_Interface
+;			(0 => return capabilities)
+; exit	R0 => base of resizable block
+;	R1 =  size of resizable block
+;	R2 => base of fixed block (or -1 if no fixed block)
+;	R3 =  size of fixed block (or document in resizable block)
+;	VC if resize successful, VS and R0 => error otherwise
+
+aw_callback	TEQ	R11,#3
+		TEQEQ	R0,#0
+		MOVEQ	R0,#1<<10		;background colour supplied
+		TEQ	R11,#0
+		LDREQ	R11,=aw_temp
+		MOVNE	PC,R14
+
+		CMP	R0,#-1			;read block size?
+		LDRNE	R2,[R11,#aw_rsz_size]
+		MOVNE	R1,R0			;new block size
+		LDR	R0,[R11,#aw_rsz_block]
+		BEQ	aw_read
+
+		; Note: because ArtworksRenderer seems to call
+		;	this routine for every scanline rendered
+		;	we never call realloc unless we have to in
+		;	order to expand the block. Also it calls
+		;	us with a size request of 0 which we must
+		;	safely ignore otherwise rendering will stop.
+
+		CMP	R1,R2
+		BLS	aw_read
+
+		STMFD	R13!,{R1,R10-R12,R14}
+		LDR	sl,[R11,#aw_sl]
+		LDR	fp,[R11,#aw_fp]
+		BL	realloc
+		LDMFD	R13!,{R1,R10-R12,R14}
+
+		CMP	R0,#0			;did it work?
+		BEQ	aw_nomem
+
+		STR	R0,[R11]
+		STR	R1,[R11,#aw_rsz_size]
+
+aw_read		; return details of fixed block
+
+		LDR	R2,[R11,#aw_fixed_block]
+		LDR	R3,[R11,#aw_fixed_size]
+		SUBS	R11,R11,R11		;clear V
+		MOV	PC,R14
+
+aw_nomem	STMFD	R13!,{R10,R12,R14}
+		LDR	sl,[R11,#aw_sl]
+		LDR	fp,[R11,#aw_fp]
+		ADR	R0,tok_nomem
+		BL	messages_get
+		MOV	a2,a1
+		LDR	a1,=errblk + 4
+		BL	strcpy
+		SUB	R0,R0,#4		;error number already 0
+		MOV	R11,#0			;restore reason code
+		CMP	PC,#1<<31		;set V
+		LDMFD	R13!,{R10,R12,PC}
+
+tok_nomem	=	"NoMemory",0
+		ALIGN
+
+
+		AREA	|ARM$$zidata|,DATA,NOINIT
+
+aw_temp		%	sizeof_aw
+errblk		%	256
+
+		END
+
+#elif defined(__ELF__)
+
+		.text
+
+.set aw_rsz_block, 0
+.set aw_rsz_size, 4
+.set aw_fixed_block, 8
+.set aw_fixed_size, 12
+.set aw_sl, 16
+.set aw_fp, 20
+.set sizeof_aw, 24
+
+@ os_error *awrender_init(byte **doc, size_t *doc_size, void *init_routine, void *init_workspace);
+
+		.global awrender_init
+awrender_init:	MOV	ip,sp
+		STMFD	sp!,{a1,a2,v1,v2,fp,ip,lr,pc}
+		SUB	fp,ip,#4
+		SUB	ip,sp,#512
+		CMP	ip,sl
+		BLMI	__rt_stkovf_split_big
+
+		LDR	v2,=aw_temp
+		LDR	a1,[a1]
+		MOV	v1,a3
+		LDR	a3,[a2]
+		MOV	ip,a4
+		STR	a1,[v2,#aw_rsz_block]
+		STR	a3,[v2,#aw_rsz_size]
+		MOV	a2,#-1
+		STR	a2,[v2,#aw_fixed_block]
+		STR	a3,[v2,#aw_fixed_size]
+		STR	sl,[v2,#aw_sl]
+		STR	fp,[v2,#aw_fp]
+		ADR	a2,aw_callback
+		MOV	lr,pc
+		MOV	pc,v1
+		MOVVC	a1,#0
+
+		@ return updated block ptr & size to caller
+
+		LDR	a2,[fp,#-28]
+		LDR	a3,[fp,#-24]
+		LDR	ip,[v2,#aw_rsz_block]
+		LDR	lr,[v2,#aw_rsz_size]
+		STR	ip,[a2]
+		STR	lr,[a3]
+
+		LDMEA	fp,{v1,v2,fp,sp,pc}
+
+
+@ os_error *awrender_render(const char *doc,
+@		const struct awinfo_block *info,
+@		const os_trfm *trans,
+@		const int *vdu_vars,
+@		char **rsz_block,
+@		size_t *rsz_size,
+@		int wysiwyg_setting,
+@		int output_dest,
+@		size_t doc_size,
+@		void *routine,
+@		void *workspace);
+
+		.global	awrender_render
+awrender_render:	MOV	ip,sp
+		STMFD	sp!,{v1-v4,fp,ip,lr,pc}
+		SUB	fp,ip,#4
+		SUB	ip,sp,#512
+		CMP	ip,sl
+		BLMI	__rt_stkovf_split_big
+
+		LDR	R12,[fp,#20]
+		LDR	R14,=aw_temp
+		LDR	R5,[fp,#4]
+		LDR	R6,[fp,#12]
+		LDR	R4,[R5]				@ resizable block
+		LDR	R7,[fp,#16]
+		STR	R4,[R14,#aw_rsz_block]
+		STR	R0,[R14,#aw_fixed_block]	@ document ptr
+		STR	R12,[R14,#aw_fixed_size]	@ document size
+		LDR	R12,[fp,#8]
+
+		STR	R5,[sp,#-4]!			@ ptr to receive block
+		STR	R12,[sp,#-4]!			@ ptr to receive size
+
+		LDR	R12,[R12]
+		ADR	R5,aw_callback
+		STR	R12,[R14,#aw_rsz_size]
+
+		STR	sl,[R14,#aw_sl]
+		STR	fp,[R14,#aw_fp]
+
+		LDR	R12,[fp,#28]
+		MOV	lr,pc
+		LDR	pc,[fp,#24]
+		MOVVC	a1,#0
+
+		@ return updated block ptr & size to caller
+
+		LDR	R7,=aw_temp
+		LDR	R12,[sp],#4
+		LDR	R4,[sp],#4
+		LDR	R5,[R7,#aw_rsz_size]
+		LDR	R6,[R7,#aw_rsz_block]
+		STR	R5,[R12]
+		STR	R6,[R4]
+
+		LDMEA	fp,{v1-v4,fp,sp,pc}
+
+
+@ Callback routine for block resizing
+@ (passed to AWRender init and render routines)
+@
+@ entry	R11 = reason code
+@		0 = CallBackReason_Memory
+@		3 = CallBackReason_Interface
+@			(0 => return capabilities)
+@ exit	R0 => base of resizable block
+@	R1 =  size of resizable block
+@	R2 => base of fixed block (or -1 if no fixed block)
+@	R3 =  size of fixed block (or document in resizable block)
+@	VC if resize successful, VS and R0 => error otherwise
+
+aw_callback:	TEQ	R11,#3
+		TEQEQ	R0,#0
+		MOVEQ	R0,#1<<10		@ background colour supplied
+		TEQ	R11,#0
+		LDREQ	R11,=aw_temp
+		MOVNE	PC,R14
+
+		CMP	R0,#-1			@ read block size?
+		LDRNE	R2,[R11,#aw_rsz_size]
+		MOVNE	R1,R0			@ new block size
+		LDR	R0,[R11,#aw_rsz_block]
+		BEQ	aw_read
+
+		@ Note: because ArtworksRenderer seems to call
+		@	this routine for every scanline rendered
+		@	we never call realloc unless we have to in
+		@	order to expand the block. Also it calls
+		@	us with a size request of 0 which we must
+		@	safely ignore otherwise rendering will stop.
+
+		CMP	R1,R2
+		BLS	aw_read
+
+		STMFD	R13!,{R1,R10-R12,R14}
+		LDR	sl,[R11,#aw_sl]
+		LDR	fp,[R11,#aw_fp]
+		BL	realloc
+		LDMFD	R13!,{R1,R10-R12,R14}
+
+		CMP	R0,#0			@ did it work?
+		BEQ	aw_nomem
+
+		STR	R0,[R11]
+		STR	R1,[R11,#aw_rsz_size]
+
+aw_read:	@ return details of fixed block
+
+		LDR	R2,[R11,#aw_fixed_block]
+		LDR	R3,[R11,#aw_fixed_size]
+		SUBS	R11,R11,R11		@ clear V
+		MOV	PC,R14
+
+aw_nomem:	STMFD	R13!,{R10,R12,R14}
+		LDR	sl,[R11,#aw_sl]
+		LDR	fp,[R11,#aw_fp]
+		ADR	R0,tok_nomem
+		BL	messages_get
+		MOV	a2,a1
+		LDR	a1,=errblk + 4
+		BL	strcpy
+		SUB	R0,R0,#4		@ error number already 0
+		MOV	R11,#0			@ restore reason code
+		CMP	PC,#1<<31		@ set V
+		LDMFD	R13!,{R10,R12,PC}
+
+tok_nomem:	.asciz	"NoMemory"
+		.align
+
+		.bss
+
+aw_temp:	.space	sizeof_aw
+		.type	aw_temp, %object
+		.size	aw_temp, . - aw_temp
+
+errblk:		.space	256
+		.type	errblk, %object
+		.size	errblk, . - errblk
+
+		.end
+#endif
+
diff --git a/riscos/content-handlers/draw.c b/riscos/content-handlers/draw.c
new file mode 100644
index 000000000..ccb9353cd
--- /dev/null
+++ b/riscos/content-handlers/draw.c
@@ -0,0 +1,300 @@
+/*
+ * Copyright 2003 John M Bell <jmb202@ecs.soton.ac.uk>
+ *
+ * This file is part of NetSurf, http://www.netsurf-browser.org/
+ *
+ * NetSurf is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * NetSurf is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** \file
+ * Content for image/x-drawfile (RISC OS implementation).
+ *
+ * The DrawFile module is used to plot the DrawFile.
+ */
+
+#include "utils/config.h"
+#ifdef WITH_DRAW
+
+#include <string.h>
+#include <stdlib.h>
+#include "oslib/drawfile.h"
+#include "utils/config.h"
+#include "content/content_protected.h"
+#include "desktop/plotters.h"
+#include "riscos/content-handlers/draw.h"
+#include "riscos/gui.h"
+#include "utils/log.h"
+#include "utils/messages.h"
+#include "utils/talloc.h"
+#include "utils/utils.h"
+
+typedef struct draw_content {
+	struct content base;
+
+	int x0, y0;
+} draw_content;
+
+static nserror draw_create(const content_handler *handler,
+		lwc_string *imime_type, const http_parameter *params,
+		llcache_handle *llcache, const char *fallback_charset,
+		bool quirks, struct content **c);
+static bool draw_convert(struct content *c);
+static void draw_destroy(struct content *c);
+static bool draw_redraw(struct content *c, int x, int y,
+		int width, int height, const struct rect *clip,
+		float scale, colour background_colour,
+		bool repeat_x, bool repeat_y);
+static nserror draw_clone(const struct content *old, struct content **newc);
+static content_type draw_content_type(lwc_string *mime_type);
+
+static const content_handler draw_content_handler = {
+	draw_create,
+	NULL,
+	draw_convert,
+	NULL,
+	draw_destroy,
+	NULL,
+	NULL,
+	NULL,
+	draw_redraw,
+	NULL,
+	NULL,
+	draw_clone,
+	NULL,
+	draw_content_type,
+	false
+};
+
+static const char *draw_types[] = {
+	"application/drawfile",
+	"application/x-drawfile",
+	"image/drawfile",
+	"image/x-drawfile"
+};
+
+static lwc_string *draw_mime_types[NOF_ELEMENTS(draw_types)];
+
+nserror draw_init(void)
+{
+	uint32_t i;
+	lwc_error lerror;
+	nserror error;
+
+	for (i = 0; i < NOF_ELEMENTS(draw_mime_types); i++) {
+		lerror = lwc_intern_string(draw_types[i],
+				strlen(draw_types[i]),
+				&draw_mime_types[i]);
+		if (lerror != lwc_error_ok) {
+			error = NSERROR_NOMEM;
+			goto error;
+		}
+
+		error = content_factory_register_handler(draw_mime_types[i],
+				&draw_content_handler);
+		if (error != NSERROR_OK)
+			goto error;
+	}
+
+	return NSERROR_OK;
+
+error:
+	draw_fini();
+
+	return error;
+}
+
+void draw_fini(void)
+{
+	uint32_t i;
+
+	for (i = 0; i < NOF_ELEMENTS(draw_mime_types); i++) {
+		if (draw_mime_types[i] != NULL)
+			lwc_string_unref(draw_mime_types[i]);
+	}
+}
+
+nserror draw_create(const content_handler *handler,
+		lwc_string *imime_type, const http_parameter *params,
+		llcache_handle *llcache, const char *fallback_charset,
+		bool quirks, struct content **c)
+{
+	draw_content *draw;
+	nserror error;
+
+	draw = talloc_zero(0, draw_content);
+	if (draw == NULL)
+		return NSERROR_NOMEM;
+
+	error = content__init(&draw->base, handler, imime_type, params,
+			llcache, fallback_charset, quirks);
+	if (error != NSERROR_OK) {
+		talloc_free(draw);
+		return error;
+	}
+
+	*c = (struct content *) draw;
+
+	return NSERROR_OK;
+}
+
+/**
+ * Convert a CONTENT_DRAW for display.
+ *
+ * No conversion is necessary. We merely read the DrawFile dimensions and
+ * bounding box bottom-left.
+ */
+
+bool draw_convert(struct content *c)
+{
+	draw_content *draw = (draw_content *) c;
+	union content_msg_data msg_data;
+	const char *source_data;
+	unsigned long source_size;
+	const void *data;
+	os_box bbox;
+	os_error *error;
+	char title[100];
+
+	source_data = content__get_source_data(c, &source_size);
+	data = source_data;
+
+	/* BBox contents in Draw units (256*OS unit) */
+	error = xdrawfile_bbox(0, (drawfile_diagram *) data,
+			(int) source_size, 0, &bbox);
+	if (error) {
+		LOG(("xdrawfile_bbox: 0x%x: %s",
+				error->errnum, error->errmess));
+		msg_data.error = error->errmess;
+		content_broadcast(c, CONTENT_MSG_ERROR, msg_data);
+		return false;
+	}
+
+	if (bbox.x1 > bbox.x0 && bbox.y1 > bbox.y0) {
+		/* c->width & c->height stored as (OS units/2)
+		   => divide by 512 to convert from draw units */
+		c->width = ((bbox.x1 - bbox.x0) / 512);
+		c->height = ((bbox.y1 - bbox.y0) / 512);
+	}
+	else
+		/* invalid/undefined bounding box */
+		c->height = c->width = 0;
+
+	draw->x0 = bbox.x0;
+	draw->y0 = bbox.y0;
+	snprintf(title, sizeof(title), messages_get("DrawTitle"), c->width,
+			c->height, source_size);
+	content__set_title(c, title);
+
+	content_set_ready(c);
+	content_set_done(c);
+	/* Done: update status bar */
+	content_set_status(c, "");
+	return true;
+}
+
+
+/**
+ * Destroy a CONTENT_DRAW and free all resources it owns.
+ */
+
+void draw_destroy(struct content *c)
+{
+}
+
+
+/**
+ * Redraw a CONTENT_DRAW.
+ */
+
+bool draw_redraw(struct content *c, int x, int y,
+		int width, int height, const struct rect *clip,
+		float scale, colour background_colour,
+		bool repeat_x, bool repeat_y)
+{
+	draw_content *draw = (draw_content *) c;
+	os_trfm matrix;
+	const char *source_data;
+	unsigned long source_size;
+	const void *data;
+	os_error *error;
+
+	if (plot.flush && !plot.flush())
+		return false;
+
+	if (!c->width || !c->height)
+		return false;
+
+	source_data = content__get_source_data(c, &source_size);
+	data = source_data;
+
+	/* Scaled image. Transform units (65536*OS units) */
+	matrix.entries[0][0] = width * 65536 / c->width;
+	matrix.entries[0][1] = 0;
+	matrix.entries[1][0] = 0;
+	matrix.entries[1][1] = height * 65536 / c->height;
+	/* Draw units. (x,y) = bottom left */
+	matrix.entries[2][0] = ro_plot_origin_x * 256 + x * 512 -
+			draw->x0 * width / c->width;
+	matrix.entries[2][1] = ro_plot_origin_y * 256 - (y + height) * 512 -
+			draw->y0 * height / c->height;
+
+	error = xdrawfile_render(0, (drawfile_diagram *) data,
+			(int) source_size, &matrix, 0, 0);
+	if (error) {
+		LOG(("xdrawfile_render: 0x%x: %s",
+				error->errnum, error->errmess));
+		return false;
+	}
+
+	return true;
+}
+
+/**
+ * Clone a CONTENT_DRAW
+ */
+
+nserror draw_clone(const struct content *old, struct content **newc)
+{
+	draw_content *draw;
+	nserror error;
+
+	draw = talloc_zero(0, draw_content);
+	if (draw == NULL)
+		return NSERROR_NOMEM;
+
+	error = content__clone(old, &draw->base);
+	if (error != NSERROR_OK) {
+		content_destroy(&draw->base);
+		return error;
+	}
+
+	/* Simply rerun convert */
+	if (old->status == CONTENT_STATUS_READY ||
+			old->status == CONTENT_STATUS_DONE) {
+		if (draw_convert(&draw->base) == false) {
+			content_destroy(&draw->base);
+			return NSERROR_CLONE_FAILED;
+		}
+	}
+
+	*newc = (struct content *) draw;
+
+	return NSERROR_OK;
+}
+
+content_type draw_content_type(lwc_string *mime_type)
+{
+	return CONTENT_IMAGE;
+}
+
+#endif
diff --git a/riscos/content-handlers/draw.h b/riscos/content-handlers/draw.h
new file mode 100644
index 000000000..a0843202a
--- /dev/null
+++ b/riscos/content-handlers/draw.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2003 John M Bell <jmb202@ecs.soton.ac.uk>
+ *
+ * This file is part of NetSurf, http://www.netsurf-browser.org/
+ *
+ * NetSurf is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * NetSurf is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** \file
+ * Content for image/x-drawfile (RISC OS interface).
+ */
+
+#ifndef _NETSURF_RISCOS_DRAW_H_
+#define _NETSURF_RISCOS_DRAW_H_
+
+#include "utils/config.h"
+#include "utils/errors.h"
+
+#ifdef WITH_DRAW
+
+nserror draw_init(void);
+void draw_fini(void);
+
+#else
+
+#define draw_init() NSERROR_OK
+#define draw_fini() ((void) 0)
+
+#endif /* WITH_DRAW */
+
+#endif
diff --git a/riscos/content-handlers/sprite.c b/riscos/content-handlers/sprite.c
new file mode 100644
index 000000000..de65faca6
--- /dev/null
+++ b/riscos/content-handlers/sprite.c
@@ -0,0 +1,311 @@
+/*
+ * Copyright 2003 John M Bell <jmb202@ecs.soton.ac.uk>
+ *
+ * This file is part of NetSurf, http://www.netsurf-browser.org/
+ *
+ * NetSurf is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * NetSurf is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** \file
+ * Content for image/x-riscos-sprite (RISC OS implementation).
+ *
+ * No conversion is necessary: we can render RISC OS sprites directly under
+ * RISC OS.
+ */
+
+#include <string.h>
+#include <stdlib.h>
+#include "oslib/osspriteop.h"
+#include "utils/config.h"
+#include "content/content_protected.h"
+#include "desktop/plotters.h"
+#include "riscos/gui.h"
+#include "riscos/image.h"
+#include "riscos/content-handlers/sprite.h"
+#include "utils/config.h"
+#include "utils/log.h"
+#include "utils/messages.h"
+#include "utils/talloc.h"
+#include "utils/utils.h"
+
+#ifdef WITH_SPRITE
+
+typedef struct sprite_content {
+	struct content base;
+
+	void *data;
+} sprite_content;
+
+static nserror sprite_create(const content_handler *handler,
+		lwc_string *imime_type, const http_parameter *params,
+		llcache_handle *llcache, const char *fallback_charset,
+		bool quirks, struct content **c);
+static bool sprite_convert(struct content *c);
+static void sprite_destroy(struct content *c);
+static bool sprite_redraw(struct content *c, int x, int y,
+		int width, int height, const struct rect *clip,
+		float scale, colour background_colour,
+		bool repeat_x, bool repeat_y);
+static nserror sprite_clone(const struct content *old, struct content **newc);
+static content_type sprite_content_type(lwc_string *mime_type);
+
+static const content_handler sprite_content_handler = {
+	sprite_create,
+	NULL,
+	sprite_convert,
+	NULL,
+	sprite_destroy,
+	NULL,
+	NULL,
+	NULL,
+	sprite_redraw,
+	NULL,
+	NULL,
+	sprite_clone,
+	NULL,
+	sprite_content_type,
+	false
+};
+
+static const char *sprite_types[] = {
+	"image/x-riscos-sprite"
+};
+
+static lwc_string *sprite_mime_types[NOF_ELEMENTS(sprite_types)];
+
+nserror sprite_init(void)
+{
+	uint32_t i;
+	lwc_error lerror;
+	nserror error;
+
+	for (i = 0; i < NOF_ELEMENTS(sprite_mime_types); i++) {
+		lerror = lwc_intern_string(sprite_types[i],
+				strlen(sprite_types[i]),
+				&sprite_mime_types[i]);
+		if (lerror != lwc_error_ok) {
+			error = NSERROR_NOMEM;
+			goto error;
+		}
+
+		error = content_factory_register_handler(sprite_mime_types[i],
+				&sprite_content_handler);
+		if (error != NSERROR_OK)
+			goto error;
+	}
+
+	return NSERROR_OK;
+
+error:
+	sprite_fini();
+
+	return error;
+}
+
+void sprite_fini(void)
+{
+	uint32_t i;
+
+	for (i = 0; i < NOF_ELEMENTS(sprite_mime_types); i++) {
+		if (sprite_mime_types[i] != NULL)
+			lwc_string_unref(sprite_mime_types[i]);
+	}
+}
+
+nserror sprite_create(const content_handler *handler,
+		lwc_string *imime_type, const http_parameter *params,
+		llcache_handle *llcache, const char *fallback_charset,
+		bool quirks, struct content **c)
+{
+	sprite_content *sprite;
+	nserror error;
+
+	sprite = talloc_zero(0, sprite_content);
+	if (sprite == NULL)
+		return NSERROR_NOMEM;
+
+	error = content__init(&sprite->base, handler, imime_type, params,
+			llcache, fallback_charset, quirks);
+	if (error != NSERROR_OK) {
+		talloc_free(sprite);
+		return error;
+	}
+
+	*c = (struct content *) sprite;
+
+	return NSERROR_OK;
+}
+
+/**
+ * Convert a CONTENT_SPRITE for display.
+ *
+ * No conversion is necessary. We merely read the sprite dimensions.
+ */
+
+bool sprite_convert(struct content *c)
+{
+	sprite_content *sprite = (sprite_content *) c;
+	os_error *error;
+	int w, h;
+	union content_msg_data msg_data;
+	const char *source_data;
+	unsigned long source_size;
+	const void *sprite_data;
+	char title[100];
+
+	source_data = content__get_source_data(c, &source_size);
+
+	sprite_data = source_data - 4;
+	osspriteop_area *area = (osspriteop_area*) sprite_data;
+	sprite->data = area;
+
+	/* check for bad data */
+	if ((int)source_size + 4 != area->used) {
+		msg_data.error = messages_get("BadSprite");
+		content_broadcast(c, CONTENT_MSG_ERROR, msg_data);
+		return false;
+	}
+
+	error = xosspriteop_read_sprite_info(osspriteop_PTR,
+			(osspriteop_area *)0x100,
+			(osspriteop_id) ((char *) area + area->first),
+			&w, &h, NULL, NULL);
+	if (error) {
+		LOG(("xosspriteop_read_sprite_info: 0x%x: %s",
+				error->errnum, error->errmess));
+		msg_data.error = error->errmess;
+		content_broadcast(c, CONTENT_MSG_ERROR, msg_data);
+		return false;
+	}
+
+	c->width = w;
+	c->height = h;
+	snprintf(title, sizeof(title), messages_get("SpriteTitle"), c->width,
+				c->height, source_size);
+	content__set_title(c, title);
+	content_set_ready(c);
+	content_set_done(c);
+	/* Done: update status bar */
+	content_set_status(c, "");
+	return true;
+}
+
+
+/**
+ * Destroy a CONTENT_SPRITE and free all resources it owns.
+ */
+
+void sprite_destroy(struct content *c)
+{
+	/* do not free c->data.sprite.data at it is simply a pointer to
+	 * 4 bytes beforec->source_data. */
+}
+
+
+/**
+ * Redraw a CONTENT_SPRITE.
+ */
+
+bool sprite_redraw(struct content *c, int x, int y,
+		int width, int height, const struct rect *clip,
+		float scale, colour background_colour,
+		bool repeat_x, bool repeat_y)
+{
+	sprite_content *sprite = (sprite_content *) c;
+
+	if (plot.flush && !plot.flush())
+		return false;
+
+	return image_redraw(sprite->data,
+			ro_plot_origin_x + x * 2,
+			ro_plot_origin_y - y * 2,
+			width, height,
+			c->width,
+			c->height,
+			background_colour,
+			false, false, false,
+			IMAGE_PLOT_OS);
+}
+
+nserror sprite_clone(const struct content *old, struct content **newc)
+{
+	sprite_content *sprite;
+	nserror error;
+
+	sprite = talloc_zero(0, sprite_content);
+	if (sprite == NULL)
+		return NSERROR_NOMEM;
+
+	error = content__clone(old, &sprite->base);
+	if (error != NSERROR_OK) {
+		content_destroy(&sprite->base);
+		return error;
+	}
+
+	/* Simply rerun convert */
+	if (old->status == CONTENT_STATUS_READY ||
+			old->status == CONTENT_STATUS_DONE) {
+		if (sprite_convert(&sprite->base) == false) {
+			content_destroy(&sprite->base);
+			return NSERROR_CLONE_FAILED;
+		}
+	}
+
+	*newc = (struct content *) sprite;
+
+	return NSERROR_OK;
+}
+
+content_type sprite_content_type(lwc_string *mime_type)
+{
+	return CONTENT_IMAGE;
+}
+
+#endif
+
+
+/**
+ * Returns the bit depth of a sprite
+ *
+ * \param   s   sprite
+ * \return  depth in bpp
+ */
+
+byte sprite_bpp(const osspriteop_header *s)
+{
+	/* bit 31 indicates the presence of a full alpha channel 
+	 * rather than a binary mask */
+	int type = ((unsigned)s->mode >> osspriteop_TYPE_SHIFT) & 15;
+	byte bpp = 0;
+
+	switch (type) {
+		case osspriteop_TYPE_OLD:
+		{
+			bits psr;
+			int val;
+			if (!xos_read_mode_variable(s->mode, 
+					os_MODEVAR_LOG2_BPP, &val, &psr) &&
+					!(psr & _C))
+				bpp = 1 << val;
+		}
+		break;
+		case osspriteop_TYPE1BPP:  bpp = 1; break;
+		case osspriteop_TYPE2BPP:  bpp = 2; break;
+		case osspriteop_TYPE4BPP:  bpp = 4; break;
+		case osspriteop_TYPE8BPP:  bpp = 8; break;
+		case osspriteop_TYPE16BPP: bpp = 16; break;
+		case osspriteop_TYPE32BPP: bpp = 32; break;
+		case osspriteop_TYPE_CMYK: bpp = 32; break;
+	}
+	return bpp;
+}
diff --git a/riscos/content-handlers/sprite.h b/riscos/content-handlers/sprite.h
new file mode 100644
index 000000000..79e02f44b
--- /dev/null
+++ b/riscos/content-handlers/sprite.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright 2003 John M Bell <jmb202@ecs.soton.ac.uk>
+ *
+ * This file is part of NetSurf, http://www.netsurf-browser.org/
+ *
+ * NetSurf is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * NetSurf is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** \file
+ * Content for image/x-riscos-sprite (RISC OS interface).
+ */
+
+#ifndef _NETSURF_RISCOS_SPRITE_H_
+#define _NETSURF_RISCOS_SPRITE_H_
+
+#include "utils/config.h"
+#include "utils/errors.h"
+
+#ifdef WITH_SPRITE
+
+nserror sprite_init(void);
+void sprite_fini(void);
+
+#else
+
+#define sprite_init() NSERROR_OK
+#define sprite_fini() ((void) 0)
+
+#endif
+
+byte sprite_bpp(const osspriteop_header *s);
+
+#endif