Health meter. Take damage from flies, gain life from food.

Makefile

@@ -25,7 +25,8 @@ SRC = main.asm \
       food.asm \
       explode.asm \
       points.asm \
-      random.asm
+      random.asm \
+      health.asm
 
 OBJ = $(patsubst %.asm,.b/%.o,$(SRC)) .b/trig.o
 

fly.asm

@@ -18,6 +18,7 @@ COLLISION_SWATTER_FLY_V_HITBOX = 10
 
 .importzp player_screen, player_h, player_owns_swatter
 .importzp player_injury, player_iframe, player_gravity, player_gravity_low
+.importzp player_health_delta
 .importzp camera_h, camera_screen
 .importzp spawn_count
 .importzp draw_h, draw_v, draw_screen
@@ -228,6 +229,7 @@ DidCollide:
   mov player_iframe, #100
   mov player_gravity, #$fe
   mov player_gravity_low, #$00
+  dec player_health_delta
   jmp Return
 Next:
 .endscope

food.asm

@@ -15,6 +15,7 @@
 .include ".b/pictures.h.asm"
 
 .importzp camera_h, camera_screen
+.importzp player_health_delta
 .importzp have_spawned_food
 .importzp draw_screen
 .importzp values
@@ -28,6 +29,10 @@ FOOD_KIND_APPLE = 0
 FOOD_KIND_STEAK = 1
 
 
+LIFE_GAIN_APPLE = 2
+LIFE_GAIN_STEAK = 5
+
+
 .segment "CODE"
 
 
@@ -114,10 +119,16 @@ DidCollide:
   beq PointsApple
   bne PointsSteak
 PointsApple:
+  lda #LIFE_GAIN_APPLE
   ldy #POINTS_APPLE
-  skip2
+  jmp Okay
 PointsSteak:
+  lda #LIFE_GAIN_STEAK
   ldy #POINTS_STEAK
+Okay:
+  clc
+  adc player_health_delta
+  sta player_health_delta
   jsr PointsGainAndCreate
   jsr ObjectFree
   jmp Return

health.asm

@@ -0,0 +1,75 @@
+.export HealthSetMax
+.export HealthApplyDelta
+
+.include "include.branch-macros.asm"
+.include "include.mov-macros.asm"
+.include "render_action.h.asm"
+
+.importzp player_health, player_health_delta
+
+HEALTH_FILL_TILE  = $af
+HEALTH_EMPTY_TILE = $b0
+
+HEALTH_MAX = 5
+
+HEALTH_METER_PPU_HIGH = $20
+HEALTH_METER_PPU_LOW  = $64
+
+
+.segment "CODE"
+
+.proc HealthSetMax
+  mov player_health, #HEALTH_MAX
+  mov player_health_delta, #0
+  jmp RenderHealthMeter
+.endproc
+
+
+.proc HealthApplyDelta
+  lda player_health_delta
+  clc
+  adc player_health
+  bmi Negative
+  cmp #HEALTH_MAX
+  blt Okay
+Max:
+  lda #HEALTH_MAX
+  bne Okay
+Negative:
+  lda #0
+Okay:
+  sta player_health
+  mov player_health_delta, #0
+  jsr RenderHealthMeter
+  lda player_health
+  beq Failure
+Success:
+  sec
+  rts
+Failure:
+  clc
+  rts
+.endproc
+
+
+.proc RenderHealthMeter
+  lda #5
+  jsr AllocateRenderAction
+  mov {render_action_addr_high,y}, #HEALTH_METER_PPU_HIGH
+  mov {render_action_addr_low,y}, #HEALTH_METER_PPU_LOW
+  ldx #0
+Loop:
+  cpx player_health
+  blt FillOne
+EmptyOne:
+  mov {render_action_data,y}, #HEALTH_EMPTY_TILE
+  bne Increment
+FillOne:
+  mov {render_action_data,y}, #HEALTH_FILL_TILE
+Increment:
+  iny
+  inx
+  cpx #HEALTH_MAX
+  blt Loop
+  rts
+.endproc

health.h.asm

@@ -0,0 +1,2 @@
+.import HealthSetMax
+.import HealthApplyDelta

hud_display.asm

@@ -14,6 +14,7 @@ SPRITE_0_TILE = $2b
 .importzp ppu_ctrl_current, bg_x_scroll, bg_nt_select
 
 .segment "CODE"
+
 .proc HudSplitAssign
   mov $200, #19
   mov $201, #SPRITE_0_TILE

main.asm

@@ -14,6 +14,7 @@
 .include "fly.h.asm"
 .include "food.h.asm"
 .include "random.h.asm"
+.include "health.h.asm"
 
 .importzp bg_x_scroll, bg_y_scroll, main_yield, ppu_ctrl_current, debug_mode
 .import palette, graphics0, graphics1
@@ -71,6 +72,7 @@ Wait1:
 
   jsr HudDataFill
   jsr LevelDataFillEntireScreen
+  jsr HealthSetMax
 
   jsr RandomSeedInit
   jsr PlayerInit
@@ -132,6 +134,9 @@ GameplayLoop:
   DebugModeSetTint red
   jsr FlashEarnedCombo
 
+  DebugModeSetTint green
+  jsr HealthApplyDelta
+
   DebugModeSetTint 0
   jsr MaybeDebugToggle
 

vars.asm

@@ -25,6 +25,8 @@ player_owns_swatter: .byte 0
 player_state: .byte 0
 player_collision_idx: .byte 0
 player_animate: .byte 0
+player_health: .byte 0
+player_health_delta: .byte 0
 player_injury: .byte 0
 player_iframe: .byte 0
 camera_h: .byte 0
@@ -72,7 +74,8 @@ have_spawned_food: .byte 0
 .exportzp player_v, player_h, player_h_low, player_screen, player_dir
 .exportzp player_gravity, player_gravity_low, player_render_v, player_render_h
 .exportzp player_owns_swatter, player_state, player_collision_idx
-.exportzp player_animate, player_injury, player_iframe
+.exportzp player_animate, player_health, player_health_delta
+.exportzp player_injury, player_iframe
 .exportzp camera_h, camera_screen
 .exportzp values, pointer
 .exportzp NMI_SCROLL_target, NMI_SCROLL_strip_id, NMI_SCROLL_action