# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1541873168 -3600
# Node ID 849db491104b644b2cafb1ddd090c48ad3df5967
# Parent  56b5497336325b89da4405aac3affc5ac2240a48
Moved sprite operations to the image module.

diff -r 56b549733632 -r 849db491104b examples/vga/main.c
--- a/examples/vga/main.c	Sat Nov 10 18:53:06 2018 +0100
+++ b/examples/vga/main.c	Sat Nov 10 19:06:08 2018 +0100
@@ -114,47 +114,6 @@
 
 
 
-/* Copy to the store from the display, then blit the image. */
-
-static void plot_sprite(sprite_t *s, int x, int y, int key)
-{
-    int frame = display_config.frame;
-    position_t *p = image_get_stored_position(s->regions, frame);
-
-    /* Copy to the stored region. */
-
-    display_copy(&display_config, image_get_stored_region(s->regions, frame),
-                 s->image->width, s->image->height / s->yscale, 1,
-                 x, y, -1, 0);
-
-    /* Plot to the screen. */
-
-    display_copy(&display_config, s->image->image,
-                 s->image->width, s->image->height, s->yscale,
-                 x, y, key, 1);
-
-    /* Record the stored background details. */
-
-    p->x = x;
-    p->y = y;
-
-    if (frame >= s->regions->stored)
-        s->regions->stored = frame + 1;
-}
-
-/* Copy to the display from the store, restoring the original background. */
-
-static void unplot_sprite(sprite_t *s)
-{
-    int frame = display_config.frame;
-    position_t *p = image_get_stored_position(s->regions, frame);
-
-    if (s->regions->stored > frame)
-        display_copy(&display_config, image_get_stored_region(s->regions, frame),
-                     s->image->width, s->image->height / s->yscale, 1,
-                     p->x, p->y, -1, 1);
-}
-
 /* Plot the revealed region at the edge of the screen after scrolling. */
 
 static void plot_screen_edge(viewport_t *v, int xorigin, int yorigin,
@@ -232,7 +191,7 @@
 {
     /* Stores of background details, replotted when moving the sprite. */
 
-    Sprite(s, &sprite, FRAME_COUNT, SOURCE_YSTEP);
+    Sprite(s, &sprite, &display_config, SOURCE_YSTEP);
 
     /* Sprite position. */
 
@@ -264,7 +223,7 @@
         {
             for (x = 0; x < display_config.line_length - s.image->width; x++)
             {
-                plot_sprite(&s, x, y, 0x8c);
+                image_plot_sprite(&s, x, y, 0x8c);
 
                 /* Update the display with the frame details. */
 
@@ -277,7 +236,7 @@
 
                 /* Prepare the frame for updates. */
 
-                unplot_sprite(&s);
+                image_unplot_sprite(&s);
 
                 /* Scroll in the indicated direction. */
 
diff -r 56b549733632 -r 849db491104b include/image.h
--- a/include/image.h	Sat Nov 10 18:53:06 2018 +0100
+++ b/include/image.h	Sat Nov 10 19:06:08 2018 +0100
@@ -86,13 +86,17 @@
 
     int yscale;
 
+    /* The display associated with the sprite. */
+
+    display_config_t *cfg;
+
 } sprite_t;
 
 
 
 /* Initialise stored regions, allocating memory and a structure to access it.
 
-   Stored_Regions(<name>, int, int)
+   Stored_Regions(<name>, int frames, int size)
 */
 
 #define Stored_Regions(NAME, FRAMES, SIZE)          \
@@ -115,15 +119,22 @@
 /* Initialise a sprite object using an existing image, creating stored regions
    for the animation of the sprite.
 
-   Sprite(<name>, image_t *, int, int)
+   Sprite(<name>, image_t *image, display_config_t *cfg, int yscale)
 */
 
-#define Sprite(NAME, IMAGE, FRAMES, YSCALE)                         \
-    Stored_Regions(__##NAME##_regions, FRAMES,                      \
+#define Sprite(NAME, IMAGE, CFG, YSCALE)                            \
+    Stored_Regions(__##NAME##_regions, (CFG)->frames,               \
                    (IMAGE)->width * (IMAGE)->height * (YSCALE));    \
     sprite_t NAME = {                                               \
         .image=IMAGE,                                               \
         .regions=&(__##NAME##_regions),                             \
-        .yscale=YSCALE};
+        .yscale=YSCALE,                                             \
+        .cfg=CFG};
+
+/* Plotting operations. */
+
+void image_plot_sprite(sprite_t *s, int x, int y, int key);
+
+void image_unplot_sprite(sprite_t *s);
 
 #endif /* __IMAGE_H__ */
diff -r 56b549733632 -r 849db491104b lib/image.c
--- a/lib/image.c	Sat Nov 10 18:53:06 2018 +0100
+++ b/lib/image.c	Sat Nov 10 19:06:08 2018 +0100
@@ -17,6 +17,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "display.h"
 #include "image.h"
 
 
@@ -34,3 +35,49 @@
 {
     return r->image + r->size * frame;
 }
+
+
+
+/* Copy a region from the screen to the store, then blit the image. */
+
+void image_plot_sprite(sprite_t *s, int x, int y, int key)
+{
+    int frame = s->cfg->frame;
+    position_t *p = image_get_stored_position(s->regions, frame);
+
+    /* Copy to the stored region. */
+
+    display_copy(s->cfg, image_get_stored_region(s->regions, frame),
+                 s->image->width, s->image->height / s->yscale, 1,
+                 x, y, -1, 0);
+
+    /* Plot to the screen. */
+
+    display_copy(s->cfg, s->image->image,
+                 s->image->width, s->image->height, s->yscale,
+                 x, y, key, 1);
+
+    /* Record the stored background details. */
+
+    p->x = x;
+    p->y = y;
+
+    if (frame >= s->regions->stored)
+        s->regions->stored = frame + 1;
+}
+
+/* Copy a region from the store to the screen, restoring the original
+   background. */
+
+void image_unplot_sprite(sprite_t *s)
+{
+    int frame = s->cfg->frame;
+    position_t *p = image_get_stored_position(s->regions, frame);
+
+    /* Only unplot the sprite if a region was stored for the frame. */
+
+    if (s->regions->stored > frame)
+        display_copy(s->cfg, image_get_stored_region(s->regions, frame),
+                     s->image->width, s->image->height / s->yscale, 1,
+                     p->x, p->y, -1, 1);
+}