add dynamically-colored buff effect (seen on healing potions)

CMakeLists.txt

@@ -90,6 +90,7 @@ set(ASSETS
   assets-cg/items/sword1.aseprite
   assets-cg/items/sword2.aseprite
   assets-cg/items/armor1.aseprite
+  assets-cg/items/buff.aseprite
   # Player animations
   assets-cg/player/player_up.aseprite
   assets-cg/player/player_right.aseprite

assets-cg/items/fxconv-metadata.txt

@@ -3,3 +3,6 @@
   name_regex: (.*)\.aseprite frames_item_\1
   next: Item=Item
   profile: p4
+
+buff.aseprite:
+  section: .data

src/anim.c

@@ -82,6 +82,7 @@ ANIM1(item_stick2);
 ANIM1(item_sword1);
 ANIM1(item_sword2);
 ANIM1(item_armor1);
+ANIM1(item_buff);
 
 /* Animation functions. */
 

src/anim.h

@@ -126,6 +126,7 @@ extern anim_t anims_item_stick2;
 extern anim_t anims_item_sword1;
 extern anim_t anims_item_sword2;
 extern anim_t anims_item_armor1;
+extern anim_t anims_item_buff;
 
 /* Expand definitions for enemies */
 

src/comp/particle.c

@@ -1,6 +1,7 @@
 #include "comp/entity.h"
 #include "comp/physical.h"
 #include "comp/particle.h"
+#include "anim.h"
 #include "geometry.h"
 #include "util.h"
 
@@ -17,9 +18,10 @@ entity_t *particle_make_damage(entity_t *target, int damage, int color)
 
     p->type = PARTICLE_DAMAGE;
     p->plane = CEILING;
+    p->bound_to_entity = false;
     p->x = target_p->x;
-    p->y = target_p->y - fix(0.5);
-    p->z = 0;
+    p->y = target_p->y;
+    p->z = fix(0.5);
     p->age = 0;
 
     p->DAMAGE.damage = damage;
@@ -37,6 +39,7 @@ entity_t *particle_make_dash(entity_t *target)
 
     p->type = PARTICLE_DASH;
     p->plane = HORIZONTAL;
+    p->bound_to_entity = false;
     p->x = target_p->x;
     p->y = target_p->y;
     p->z = 0;
@@ -45,6 +48,23 @@ entity_t *particle_make_dash(entity_t *target)
     return e;
 }
 
+entity_t *particle_make_buff(entity_t *target, int color)
+{
+    entity_t *e = entity_make(particle);
+    particle_t *p = getcomp(e, particle);
+
+    p->type = PARTICLE_BUFF;
+    p->plane = CEILING;
+    p->bound_to_entity = true;
+    p->bound_entity = target;
+    p->z = fix(0.5);
+    p->age = 0;
+
+    p->BUFF.color = color;
+
+    return e;
+}
+
 static bool damage_update(particle_t *p, GUNUSED fixed_t dt)
 {
     return p->age >= 300;
@@ -75,6 +95,50 @@ static void dash_render(int x, int y, particle_t const *p)
     }
 }
 
+static bool buff_update(particle_t *p, GUNUSED fixed_t dt)
+{
+    int total_ms = 0;
+    anim_frame_t const *frame = anims_item_buff.start[0];
+    while(frame) {
+        total_ms += frame->duration;
+        frame = frame->next;
+    }
+
+    return p->age >= total_ms;
+}
+
+static void buff_render(int x, int y, particle_t const *p)
+{
+    int ms = p->age;
+    anim_frame_t const *frame = anims_item_buff.start[0];
+    while(frame && ms > frame->duration) {
+        ms -= frame->duration;
+        frame = frame->next;
+    }
+    if(!frame)
+        return;
+
+    /* Find black and white in the palette */
+    int black_index = -1;
+    int white_index = -1;
+    for(int i = 0; i < frame->sheet->color_count; i++) {
+        if(black_index == -1 && frame->sheet->palette[i] == 0x0000)
+            black_index = i;
+        if(white_index == -1 && frame->sheet->palette[i] == 0xffff)
+            white_index = i;
+    }
+
+    /* Render while swapping black for p->BUFF.color */
+    frame->sheet->palette[black_index] = p->BUFF.color;
+    frame->sheet->palette[white_index] = ~((~p->BUFF.color & 0xf7de) >> 1);
+
+    dsubimage_p4(x - frame->cx, y - frame->cy, frame->sheet,
+        frame->x, frame->y, frame->w, frame->h, DIMAGE_NONE);
+
+    frame->sheet->palette[black_index] = 0x0000;
+    frame->sheet->palette[white_index] = 0xffff;
+}
+
 //---
 // Generic functions
 //---
@@ -87,6 +151,8 @@ bool particle_update(particle_t *p, fixed_t dt)
         return damage_update(p, dt);
     if(p->type == PARTICLE_DASH)
         return dash_update(p, dt);
+    if(p->type == PARTICLE_BUFF)
+        return buff_update(p, dt);
 
     return true;
 }
@@ -97,4 +163,6 @@ void particle_render(int x, int y, particle_t const *p)
         return damage_render(x, y, p);
     if(p->type == PARTICLE_DASH)
         return dash_render(x, y, p);
+    if(p->type == PARTICLE_BUFF)
+        return buff_render(x, y, p);
 }

src/comp/particle.h

@@ -17,6 +17,7 @@ enum {
     PARTICLE_DAMAGE,
     PARTICLE_DASH,
     PARTICLE_HPBAR,
+    PARTICLE_BUFF,
 };
 
 typedef struct
@@ -25,10 +26,18 @@ typedef struct
     uint8_t type;
     /* Plane of rendering */
     uint8_t plane;
+    /* Whether the particle's position is bound to an entity, or absolute */
+    bool bound_to_entity;
+
     /* Location on screen and in the air */
-    fixed_t x, y, z;
-    /* Age and lifetime */
-    fixed_t age;
+    union {
+        struct { fixed_t x, y; };
+        entity_t *bound_entity;
+    };
+    fixed_t z;
+    /* Age (milliseconds) */
+    int age;
+
     /* 8 bytes of data */
     union {
         /* Generic particles or with a lot of extra data */
@@ -39,6 +48,8 @@ typedef struct
 
         /* PARTICLE_HPBAR: Pointer to entity */
         struct { entity_t *entity; } HPBAR;
+        /* PARTICLE_BUFF: Buff animation */
+        struct { uint16_t color; } BUFF;
     };
 
 } particle_t;
@@ -49,6 +60,9 @@ entity_t *particle_make_damage(entity_t *target, int damage, int color);
 /* Make a dashing particle at the specified target's position */
 entity_t *particle_make_dash(entity_t *target);
 
+/* Make a buff particle of the specified color bound to the specified target */
+entity_t *particle_make_buff(entity_t *target, int color);
+
 /* Update time and layout for a particle (type-generic). */
 bool particle_update(particle_t *p, fixed_t dt);
 

src/game.c

@@ -414,6 +414,14 @@ void game_remove_dead_entities(game_t *g)
         }
     }
 
+    /* Remove particles bound to dead fighters */
+    for(int i = 0; i < g->entity_count; i++) {
+        entity_t *e = g->entities[i];
+        particle_t *p = getcomp(e, particle);
+        if(p && p->bound_to_entity && p->bound_entity->deleted)
+            entity_mark_to_delete(e);
+    }
+
     int i = 0;
     while(i < g->entity_count) {
         if(g->entities[i]->deleted)

src/item.c

@@ -65,6 +65,25 @@ char const *item_name(int item)
     return "???";
 }
 
+int item_buff_color(int item)
+{
+    if(item == ITEM_LIFE)
+        return C_RGB(31, 0, 31);
+    else if(item == ITEM_POTION_ATK)
+        return C_RGB(31, 16, 16);
+    else if(item == ITEM_POTION_COOLDOWN)
+        return C_BLUE;
+    else if(item == ITEM_POTION_DEF)
+        return C_RGB(0, 15, 31);
+    else if(item == ITEM_POTION_FRZ)
+        return 0x5555;
+    else if(item == ITEM_POTION_HP)
+        return C_RGB(0, 31, 0);
+    else if(item == ITEM_POTION_SPD)
+        return C_RGB(31, 31, 0);
+    return -1;
+}
+
 char const *item_description(int item)
 {
     if(item == ITEM_LIFE)

src/item.h

@@ -33,6 +33,9 @@ anim_t const *item_anim(int item);
 /* Item name (fancy huh?). */
 char const *item_name(int item);
 
+/* Buff effect color (-1 for no buff). */
+int item_buff_color(int item);
+
 /* Item description, can be multi-line. NULL if none specified. */
 char const *item_description(int item);
 

src/main.c

@@ -494,6 +494,12 @@ static int menu_select_play_repeat(void)
                 }
                 else if(item >= 0 && item_use(item, player)) {
                     player_data.inventory[game.menu_cursor] = -1;
+
+                    int color = item_buff_color(item);
+                    if(color > 0) {
+                        entity_t *part = particle_make_buff(player, color);
+                        game_add_entity(&game, part);
+                    }
                 }
             }
         }

src/render.c

@@ -182,6 +182,15 @@ void render_map_layer(map_t const *map, camera_t const *c, int ss_x, int ss_y,
 static int depth_measure(entity_t const *e, int direction)
 {
     particle_t *p = getcomp(e, particle);
+    if(p) {
+        if(p->plane != direction)
+            return -1;
+        if(!p->bound_to_entity)
+            return p->y;
+
+        physical_t *bound_p = getcomp(p->bound_entity, physical);
+        return bound_p ? bound_p->y : -1;
+    }
     if(p) {
         return (p->plane != direction) ? -1 : p->y;
     }
@@ -253,9 +262,15 @@ static void render_entities(game_t const *g, camera_t const *camera,
         visible_t *v = getcomp(e, visible);
         particle_t *pt = getcomp(e, particle);
 
-        vec2 xy;
-        fixed_t z;
-        if(pt) {
+        vec2 xy = { 0, 0 };
+        fixed_t z = 0;
+        if(pt && pt->bound_to_entity) {
+            physical_t *bound_p = getcomp(pt->bound_entity, physical);
+            if(bound_p)
+                xy = (vec2) { bound_p->x, bound_p->y };
+            z = pt->z;
+        }
+        else if(pt) {
             xy = (vec2) { pt->x, pt->y };
             z = pt->z;
         }
@@ -292,7 +307,7 @@ static void render_entities(game_t const *g, camera_t const *camera,
 
         /* Show particle */
         if(pt) {
-            particle_render(scr.x, scr.y, pt);
+            particle_render(scr.x, elevated_y, pt);
         }
     }