1 files changed, 42 insertions, 18 deletions

diff --git a/riscos/draw.c b/riscos/draw.c
index 3a1642ff1..f172de8b5 100644
--- a/riscos/draw.c
+++ b/riscos/draw.c
@@ -5,73 +5,96 @@
  * Copyright 2003 John M Bell <jmb202@ecs.soton.ac.uk>
  */
 
-#include <assert.h>
+/** \file
+ * Content for image/x-drawfile (RISC OS implementation).
+ *
+ * The DrawFile module is used to plot the DrawFile.
+ */
+
 #include <string.h>
 #include <stdlib.h>
+#include "oslib/drawfile.h"
 #include "netsurf/utils/config.h"
 #include "netsurf/content/content.h"
 #include "netsurf/riscos/draw.h"
+#include "netsurf/riscos/gui.h"
 #include "netsurf/utils/utils.h"
 #include "netsurf/utils/messages.h"
 #include "netsurf/utils/log.h"
-#include "oslib/drawfile.h"
 
 #ifdef WITH_DRAW
 
+
+/**
+ * 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, int width, int height)
 {
 	union content_msg_data msg_data;
 	os_box bbox;
 	os_error *error;
 
-        /* BBox contents in Draw units (256*OS unit) */
+	/* BBox contents in Draw units (256*OS unit) */
 	error = xdrawfile_bbox(0, (drawfile_diagram*)(c->source_data),
 			(int) c->source_size, 0, &bbox);
-        if (error) {
-                LOG(("xdrawfile_bbox: 0x%x: %s",
-                		error->errnum, error->errmess));
+	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;
-        }
+		return false;
+	}
 
-        /* c->width & c->height stored as (OS units/2)
-           => divide by 512 to convert from draw units */
+	/* 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);
-	c->data.draw.x0 = bbox.x0 / 2;
-	c->data.draw.y0 = bbox.y0 / 2;
+	c->data.draw.x0 = bbox.x0;
+	c->data.draw.y0 = bbox.y0;
 	c->title = malloc(100);
 	if (c->title)
 		snprintf(c->title, 100, messages_get("DrawTitle"), c->width,
-	                                c->height, c->source_size);
+				c->height, c->source_size);
 	c->status = CONTENT_STATUS_DONE;
 	return true;
 }
 
 
+/**
+ * Destroy a CONTENT_DRAW and free all resources it owns.
+ */
+
 void draw_destroy(struct content *c)
 {
 	free(c->title);
 }
 
 
+/**
+ * Redraw a CONTENT_DRAW.
+ */
+
 bool draw_redraw(struct content *c, int x, int y,
 		int width, int height,
 		int clip_x0, int clip_y0, int clip_x1, int clip_y1,
-		float scale, unsigned long background_colour)
+		float scale, colour background_colour)
 {
 	os_error *error;
 	os_trfm matrix;
 
 	/* Scaled image. Transform units (65536*OS units) */
-	matrix.entries[0][0] = ((width*65536) / (c->width*2));
+	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*2));
+	matrix.entries[1][1] = height * 65536 / c->height;
 	/* Draw units. (x,y) = bottom left */
-	matrix.entries[2][0] = x * 256 - c->data.draw.x0 * width / c->width;
-	matrix.entries[2][1] = (y - height) * 256 -
+	matrix.entries[2][0] = ro_plot_origin_x * 256 + x * 512 -
+			c->data.draw.x0 * width / c->width;
+	matrix.entries[2][1] = ro_plot_origin_y * 256 - (y + height) * 512 -
 			c->data.draw.y0 * height / c->height;
 
 	error = xdrawfile_render(0, (drawfile_diagram*)(c->source_data),
@@ -84,4 +107,5 @@ bool draw_redraw(struct content *c, int x, int y,
 
 	return true;
 }
+
 #endif