Static sprites now collide relative to the viewport.

docs/changelog.txt

@@ -5,8 +5,9 @@ are a lot of changes, including a large number of crash fixes.
 Brief summaries of each section:
 
 General: worlds are decrypted in memory now, MegaZeux 1.x worlds
-are now supported, you can have more custom sound effects, and
-the 1/8th random movement chance of dragons has been readded.
+are now supported, you can have more custom sound effects, the
+1/8th random movement chance of dragons has been readded, and
+static sprites now collide at their apparent position.
 
 Robotic: new label PLAYERDIED, new counter KEY_PRESSEDn, new
 counter DATE_WEEKDAY, new counter SPRn_OFFONEXIT, new viewport
@@ -74,6 +75,10 @@ GENERAL
   could cause it to rarely return a number outside of the
   expected range. This unfortunately breaks compatibility for
   the RANDOM_SEED# counter.
++ Static sprites now collide as if they are at the position on
+  the board where they are currently being drawn i.e. relative
+  to the viewport instead of at their actual X/Y position. This
+  behavior has also been added to the IF SPRITE AT # # command.
 + Optimized ccheck 3 sprite collision performance by generating
   visibility masks for characters directly instead of using an
   intermediate render and skipping pixel checks for blank chars.

src/run_robot.c

@@ -2313,7 +2313,8 @@ void run_robot(context *ctx, int id, int x, int y)
 
             for(i = check_color; i < MAX_SPRITES; i++)
             {
-              if(sprite_at_xy(mzx_world->sprite_list[i], check_x, check_y))
+              if(sprite_at_xy(mzx_world, mzx_world->sprite_list[i],
+               check_x, check_y))
                 break;
             }
             if(i == MAX_SPRITES)
@@ -2331,7 +2332,7 @@ void run_robot(context *ctx, int id, int x, int y)
           {
             if((unsigned int)check_param < 256)
             {
-              ret = sprite_at_xy(mzx_world->sprite_list[check_param],
+              ret = sprite_at_xy(mzx_world, mzx_world->sprite_list[check_param],
                check_x, check_y);
             }
           }

src/sprite.c

@@ -872,7 +872,7 @@ static inline struct rect board_rectangle(struct rect r)
   );
 }
 
-boolean sprite_at_xy(struct sprite *spr, int x, int y)
+boolean sprite_at_xy(struct world *mzx_world, struct sprite *spr, int x, int y)
 {
   struct rect sprite_rect;
   struct rect pos_rect;
@@ -884,6 +884,15 @@ boolean sprite_at_xy(struct sprite *spr, int x, int y)
   sprite_rect = sprite_rectangle(spr);
   pos_rect = rectangle(x * CHAR_W, y * CHAR_H, CHAR_W, CHAR_H);
 
+  // Static sprite collision occurs at its apparent position from 2.93 onward.
+  if((spr->flags & SPRITE_STATIC) && mzx_world->version >= V293)
+  {
+    int screen_x, screen_y;
+    calculate_xytop(mzx_world, &screen_x, &screen_y);
+    sprite_rect.x += screen_x * CHAR_W;
+    sprite_rect.y += screen_y * CHAR_H;
+  }
+
   if(rectangle_overlap(sprite_rect, pos_rect))
     return true;
   return false;
@@ -1126,6 +1135,8 @@ int sprite_colliding_xy(struct world *mzx_world, struct sprite *spr,
   struct board *cur_board = mzx_world->current_board;
   char *level_id = cur_board->level_id;
   int board_width = cur_board->board_width;
+  int screen_x = 0;
+  int screen_y = 0;
   int bx, by;
   int sprite_idx;
   int cx, cy;
@@ -1139,6 +1150,14 @@ int sprite_colliding_xy(struct world *mzx_world, struct sprite *spr,
   if(mzx_world->version < V290)
     return sprite_colliding_xy_old(mzx_world, spr, x, y);
 
+  // Adjust static sprites to match their apparent positions onscreen.
+  if(mzx_world->version >= V293)
+  {
+    calculate_xytop(mzx_world, &screen_x, &screen_y);
+    screen_x *= CHAR_W;
+    screen_y *= CHAR_H;
+  }
+
   board_rect = rectangle(
     0,
     0,
@@ -1168,6 +1187,11 @@ int sprite_colliding_xy(struct world *mzx_world, struct sprite *spr,
 
   sprite_rect = sprite_rectangle(&collision_sprite);
   col_rect = collision_rectangle(&collision_sprite);
+  if(spr->flags & SPRITE_STATIC)
+  {
+    sprite_rect.x += screen_x;
+    sprite_rect.y += screen_y;
+  }
   col_rect.x += sprite_rect.x;
   col_rect.y += sprite_rect.y;
 
@@ -1231,6 +1255,11 @@ int sprite_colliding_xy(struct world *mzx_world, struct sprite *spr,
 
     target_spr_rect = sprite_rectangle(target_spr);
     target_col_rect = collision_rectangle(target_spr);
+    if(target_spr->flags & SPRITE_STATIC)
+    {
+      target_spr_rect.x += screen_x;
+      target_spr_rect.y += screen_y;
+    }
     //debug("sprite #%d a: %d %d %d %d\n",
     // target_rect.x, target_rect.y, target_rect.w, target_rect.h);
     target_col_rect.x += target_spr_rect.x;

src/sprite.h

@@ -65,7 +65,7 @@ enum
 void plot_sprite(struct world *mzx_world, struct sprite *cur_sprite, int color,
  int x, int y);
 void draw_sprites(struct world *mzx_world);
-boolean sprite_at_xy(struct sprite *cur_sprite, int x, int y);
+boolean sprite_at_xy(struct world *mzx_world, struct sprite *cur_sprite, int x, int y);
 int sprite_colliding_xy(struct world *mzx_world, struct sprite *check_sprite,
  int x, int y);
 

testworlds/2.65/004 Static Sprite Collision.txt

@@ -0,0 +1,3 @@
+Title: Static Sprite Collision (2.65)
+Author: Alice Rowan
+Desc: Pre-2.90 static sprites display relative to the screen but do not collide relative to the screen. This world tests the original collision function from before unbound sprites.