metasprite test

.gitignore

 build
 *.gb
+.cache
+compile_commands.json
+bear.cfg
+tmp

Makefile

 BIN := duality.gb
 SRC_DIR := src
 BUILD_DIR := build
+DATA_DIR := data
 
 SRCS := $(wildcard $(SRC_DIR)/*.c)
 OBJS := $(SRCS:%.c=$(BUILD_DIR)/%.o)
 
+ASSETS := $(wildcard $(DATA_DIR)/*.png)
+SPRITES := $(ASSETS:%.png=$(BUILD_DIR)/%.c)
+OBJS += $(SPRITES:%.c=%.o)
+
 LCC := $(GBDK_HOME)/bin/lcc
+PNGA := $(GBDK_HOME)/bin/png2asset
 GB_EMU := gearboy
 
-LCCFLAGS := -Wa-l -Wl-m -Wm"-yn Duality"
+LCCFLAGS := -Wa-l -Wl-m -Wm"-yn Duality" -I$(BUILD_DIR)/$(DATA_DIR)
 EMUFLAGS := $(BIN)
 
-GBDK_DEBUG = ON
-ifdef GBDK_DEBUG
+ifndef GBDK_RELEASE
 	LCCFLAGS += -debug -Wa-j -Wa-y -Wa-s -Wl-j -Wl-y -Wl-u -Wm-yS
 	EMUFLAGS += $(BUILD_DIR)/$(BIN:.gb=.sym)
+	BUILD_TYPE = Debug
+else
+	BUILD_TYPE = Release
 endif
 
-.PHONY: all run $(BIN) clean
+$(info BUILD_TYPE is $(BUILD_TYPE))
+
+.PHONY: all run $(BIN) clean compile_commands.json
 
 all: $(BIN)
 
+compile_commands.json:
+	@echo "Cleaning old build"
+	@make clean
+	@echo "Preparing bear.cfg"
+	@echo '{"compilation":{"compilers_to_recognize":[{"executable":"$(GBDK_HOME)/bin/sdcc","flags_to_add":[""],"flags_to_remove":[""]}]}}' > bear.cfg
+	@echo "Running full build within bear"
+	@bear --config bear.cfg -- make -j4
+	@rm -rf bear.cfg
+
 run: $(BIN)
 	@echo Emulating $<
 	@$(GB_EMU) $(EMUFLAGS)
 
+.PRECIOUS: $(BUILD_DIR)/$(DATA_DIR)/%.c $(BUILD_DIR)/$(DATA_DIR)/%.h
+$(BUILD_DIR)/$(DATA_DIR)/%.c $(BUILD_DIR)/$(DATA_DIR)/%.h: $(DATA_DIR)/%.png
+	@mkdir -p $(@D)
+	$(if $(findstring _map,$<),           \
+		@echo "Converting map $<" &&  \
+		$(PNGA) $< -o $@ -spr8x8 -map \
+	,                                     \
+		@echo "Converting tile $<" && \
+		$(PNGA) $< -o $@ -spr8x8      \
+	)
+
 $(BUILD_DIR)/%.o: %.c
 	@mkdir -p $(@D)
 	@echo Compiling $<
 	@$(LCC) $(LCCFLAGS) -c -o $@ $<
 
+$(BUILD_DIR)/%.o: $(BUILD_DIR)/%.c
+	@mkdir -p $(@D)
+	@echo Compiling $<
+	@$(LCC) $(LCCFLAGS) -c -o $@ $<
+
 $(BUILD_DIR)/%.o: %.s
 	@mkdir -p $(@D)
 	@echo Assembling $<
 
 $(BUILD_DIR)/$(BIN): $(OBJS)
 	@echo Linking $@
-	@$(LCC) $(LCCFLAGS) -o $@ $<
+	@$(LCC) $(LCCFLAGS) -o $@ $(OBJS)
 
 $(BIN): $(BUILD_DIR)/$(BIN)
 	@cp $< $@

README.md

 ## Getting Started
 
 You need the [GBDK-2020](https://gbdk.org/docs/api/docs_getting_started.html) to build the ROM and [Gearboy](https://github.com/drhelius/Gearboy) to emulate it comfortably.
-Then just build and run it.
+Then just build a debug version and run it in the emulator, with debug symbols already loaded.
 
     make run
 
+For the release build, simply add `GBDK_RELEASE=1` to your make invocation after running `make clean`.
+
 ## License
 
 To-Do

src/galaxy.c

-/*
- * C version of the 'space' assembly demo.
- *
- * Little demo illustrating how to use the graphical possibilities
- *  of the GB (background, window and animated sprite)
- * I have used fixed-point values for both the position and
- *  speed of objects to get smooth movements
- * 
- * OBJ data             : 0x8000 -> 0x8FFF (unsigned)
- * Window data          : 0x8800 -> 0x97FF (unsigned)
- * Background data      : 0x8800 -> 0x97FF (signed)
- * 
- * Tiled 0xFC -> 0xFF are standard tiles (all black -> all white)
- * 
- * Keys:
- * Arrow keys           : Change the speed (and direction) of the sprite
- * Arrow keys + A       : Change the speed (and direction) of the window
- * Arrow keys + B       : Change the speed (and direction) of the background
- * START                : Open/close the door
- * SELECT               : Basic fading effect
- * 
- * Note that the window is kept in the lower right part of the screen
- * since it can't be made transparent
- */
-
-#include <gb/gb.h>
-#include <stdint.h>
-
-const unsigned char std_data[] = {
-
-  /* Basic tiles (0xFC to 0xFF) */
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,
-  0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,
-  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
-};
-
-const unsigned char earth_data[] = {
-
-  /* Tile 0x00 */
-  0x07,0x07,0x18,0x1F,0x32,0x2D,0x71,0x4E,0x70,0x4F,0xF8,0x87,0xF8,0x87,0xF8,0x87,
-  0xFC,0x83,0xFE,0x81,0x7F,0x40,0x7F,0x40,0x3F,0x20,0x1F,0x18,0x07,0x07,0x00,0x00,
-  0xC0,0xC0,0xF0,0x30,0x78,0x88,0x3C,0xC4,0x5C,0xA4,0x9E,0x62,0x3E,0xC2,0x3E,0xC2,
-  0x5E,0xA2,0x7E,0x82,0x0C,0xF4,0x0C,0xF4,0x98,0x68,0xB0,0x70,0xC0,0xC0,0x00,0x00,
-  0x07,0x07,0x1F,0x18,0x2F,0x30,0x4F,0x70,0x6F,0x50,0x9F,0xE0,0x9F,0xE0,0xBF,0xC0,
-  0xFF,0x80,0xB7,0xC8,0x63,0x5C,0x43,0x7C,0x3F,0x20,0x1F,0x18,0x07,0x07,0x00,0x00,
-  0xC0,0xC0,0xB0,0x70,0x18,0xE8,0x0C,0xF4,0x0C,0xF4,0x82,0x7E,0x82,0x7E,0x86,0x7A,
-  0xC6,0x3A,0xE6,0x1A,0xF4,0x0C,0xFC,0x04,0xF8,0x08,0xF0,0x30,0xC0,0xC0,0x00,0x00,
-
-  /* Tile 0x08 */
-  0x07,0x07,0x1E,0x19,0x20,0x3F,0x40,0x7F,0x42,0x7D,0x81,0xFE,0x81,0xFE,0x83,0xFC,
-  0xD7,0xA8,0xBB,0xC4,0x6E,0x51,0x7C,0x43,0x3F,0x20,0x1F,0x18,0x07,0x07,0x00,0x00,
-  0xC0,0xC0,0x70,0xB0,0xE8,0x18,0xF4,0x0C,0xF4,0x0C,0xFE,0x02,0xFE,0x02,0xFE,0x02,
-  0xFE,0x02,0x7E,0x82,0x3C,0xC4,0x3C,0xC4,0xF8,0x08,0xF0,0x30,0xC0,0xC0,0x00,0x00,
-  0x07,0x07,0x1B,0x1C,0x20,0x3F,0x40,0x7F,0x40,0x7F,0xE0,0x9F,0x90,0xEF,0x89,0xF6,
-  0x8D,0xF2,0x9F,0xE0,0x5E,0x61,0x6F,0x50,0x3F,0x20,0x1F,0x18,0x07,0x07,0x00,0x00,
-  0xC0,0xC0,0xB0,0x70,0x28,0xD8,0x04,0xFC,0x2C,0xD4,0x1E,0xE2,0x1E,0xE2,0x3E,0xC2,
-  0x7E,0x82,0xB6,0x4A,0xE4,0x1C,0xC4,0x3C,0xF8,0x08,0xF0,0x30,0xC0,0xC0,0x00,0x00,
-
-  /* Tile 0x10 */
-  0x07,0x07,0x18,0x1F,0x20,0x3F,0x40,0x7F,0x40,0x7F,0xEE,0x91,0xF1,0x8E,0xE0,0x9F,
-  0xE0,0x9F,0xF1,0x8E,0x71,0x4E,0x72,0x4D,0x3F,0x20,0x1F,0x18,0x07,0x07,0x00,0x00,
-  0xC0,0xC0,0xF0,0x30,0x08,0xF8,0x04,0xFC,0x04,0xFC,0x02,0xFE,0x02,0xFE,0x92,0x6E,
-  0xD6,0x2A,0xFE,0x02,0xEC,0x14,0xFC,0x04,0xF8,0x08,0xF0,0x30,0xC0,0xC0,0x00,0x00,
-  0x07,0x07,0x1D,0x1A,0x36,0x29,0x5C,0x63,0x6C,0x53,0xCE,0xB1,0x9F,0xE0,0x9E,0xE1,
-  0xAE,0xD1,0xBF,0xC0,0x47,0x78,0x47,0x78,0x2F,0x30,0x1F,0x18,0x07,0x07,0x00,0x00,
-  0xC0,0xC0,0x70,0xB0,0x08,0xF8,0x04,0xFC,0x04,0xFC,0xE2,0x1E,0x32,0xCE,0x0E,0xF2,
-  0x0E,0xF2,0x1E,0xE2,0x1C,0xE4,0x2C,0xD4,0xF8,0x08,0xF0,0x30,0xC0,0xC0,0x00,0x00,
-
-  /* Tile 0x18 */
-  0x07,0x07,0x1E,0x19,0x33,0x2C,0x49,0x76,0x42,0x7D,0xC4,0xBB,0xC1,0xBE,0xC1,0xBE,
-  0xE2,0x9D,0xF3,0x8C,0x78,0x47,0x78,0x47,0x3C,0x23,0x1C,0x1B,0x07,0x07,0x00,0x00,
-  0xC0,0xC0,0x70,0xB0,0x68,0x98,0xC4,0x3C,0xC4,0x3C,0xEE,0x12,0xF2,0x0E,0xE2,0x1E,
-  0xE2,0x1E,0xF2,0x0E,0x7C,0x84,0x7C,0x84,0xF8,0x08,0xF0,0x30,0xC0,0xC0,0x00,0x00
-};
-
-const unsigned char frame_data[] = {
-
-  /* Tile 0x00 */
-  0xFF,0x00,0x80,0x7F,0x80,0x7F,0x80,0x7F,0x80,0x7F,0x80,0x7F,0x80,0x7F,0x80,0x7F,
-  0xFF,0x00,0x01,0xFE,0x03,0xFC,0x07,0xF8,0x0F,0xF0,0x1F,0xE0,0x3F,0xC0,0x7F,0x80,
-  0xFF,0x00,0xFE,0x01,0xFC,0x03,0xF8,0x07,0xF0,0x0F,0xE0,0x1F,0xC0,0x3F,0x80,0x7F,
-  0xFF,0x00,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,
-  0xFF,0x00,0xFF,0x01,0xFD,0x03,0xF9,0x07,0xF1,0x0F,0xE1,0x1F,0xC1,0x3F,0x81,0x7F,
-  0x80,0x7F,0x81,0x7E,0x83,0x7C,0x87,0x78,0x8F,0x70,0x9F,0x60,0xBF,0x40,0xFF,0x00,
-  0xFF,0x70,0xFF,0x98,0xEF,0xB8,0xCF,0xF8,0xFF,0x70,0xFF,0x00,0xFF,0x00,0xFF,0x01,
-  0xFF,0x00,0xFE,0x01,0xFC,0x03,0xF8,0x07,0xF0,0x0F,0xE0,0x1F,0xC0,0x3F,0xFF,0xFF,
-
-  /* Tile 0x08 */
-  0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0xFF,0xFF,
-  0x00,0xFF,0x01,0xFE,0x03,0xFC,0x07,0xF8,0x0F,0xF0,0x1F,0xE0,0x3F,0xC0,0xFF,0xFF,
-  0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0xFF,
-  0xFF,0x0E,0xFF,0x13,0xFD,0x17,0xF9,0x1F,0xFE,0x0F,0xE0,0x1F,0xC0,0x3F,0x80,0xFF,
-  0x01,0xFF,0x01,0xFF,0x01,0xFF,0x01,0xFF,0x01,0xFF,0x01,0xFF,0x01,0xFF,0x01,0xFF,
-  0xFF,0x01,0xFF,0x01,0xFD,0x03,0xF9,0x07,0xF1,0x0F,0xE1,0x1F,0xC1,0x3F,0x81,0x7F,
-  0x80,0x7F,0x80,0x7F,0x80,0x7F,0x80,0x7F,0x80,0x7F,0x80,0x7F,0x80,0x7F,0x80,0x7F,
-  0x01,0xFF,0x01,0xFF,0x03,0xFD,0x07,0xF9,0x0F,0xF1,0x1F,0xE1,0x3F,0xC1,0x7F,0x81,
-
-  /* Tile 0x10 */
-  0xFF,0x01,0xFF,0x01,0xFF,0x01,0xFF,0x01,0xFF,0x01,0xFF,0x01,0xFF,0x01,0xFF,0x01,
-  0x01,0xFF,0x01,0xFE,0x03,0xFC,0x77,0xF8,0xFF,0x98,0xEF,0xB8,0xCF,0xF8,0x7F,0xF0,
-  0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x0E,0xFF,0x13,0xFD,0x17,0xF9,0x1F,0xFF,0x0E,
-  0x80,0x7F,0x81,0x7E,0x83,0x7C,0x87,0x78,0x8F,0x70,0x9F,0x60,0xBF,0x40,0xFF,0x7F,
-  0x01,0xFF,0x01,0xFF,0x01,0xFF,0x01,0xFF,0x01,0xFF,0x01,0xFF,0x01,0xFF,0xFF,0xFF,
-
-  /* Door1 */
-
-  /* Tile 0x15 */
-  0xFF,0x00,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0xFF,0xFF,0xFF,0x00,0x00,0xFF,
-  0x00,0xFF,0x00,0xFF,0x00,0xFF,0xFF,0xFF,0xFF,0x00,0x00,0xFF,0x00,0xFF,0x00,0xFF,
-  0x00,0xFF,0xFF,0xFF,0xFF,0x00,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0xFF,0xFF,
-
-  /* Door2 */
-
-  /* Tile 0x18 */
-  0x00,0xFF,0x00,0xFF,0x00,0xFF,0xFF,0xFF,0xFF,0x00,0x00,0xFF,0x00,0xFF,0x00,0xFF,
-  0x00,0xFF,0xFF,0xFF,0xFF,0x00,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0xFF,0xFF,
-  0xFF,0x00,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0xFF,0xFF,0xFF,0x00,0x00,0xFF,
-  0xFF,0x00,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-
-  /* Door3 */
-
-  /* Tile 0x1C */
-  0x00,0xFF,0xFF,0xFF,0xFF,0x00,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0xFF,0xFF,
-  0xFF,0x00,0x00,0xFF,0x00,0xFF,0x00,0xFF,0x00,0xFF,0xFF,0xFF,0xFF,0x00,0x00,0xFF,
-  0x00,0xFF,0x00,0xFF,0x00,0xFF,0xFF,0xFF,0xFF,0x00,0x00,0xFF,0x00,0xFF,0x00,0xFF,
-  0x00,0xFF,0x00,0xFF,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-
-  /* Door4 */
-
-  /* Tile 0x20 */
-  0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF
-};
-
-const unsigned char bkg_data[] = {
-
-  /* Tile 0x00 */
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xEF,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xDF,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFB,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xF7,0xF7,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xDF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x7F,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xF7,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xDF,0xFF,0xEF,0xFF,0xFF,0xF7,0xFF,0xFB,0xFF,0xFD,0xFF,0xFE,0xFE,0xFF,
-
-  /* Tile 0x08 */
-  0xFF,0xFF,0xFF,0xFF,0xF7,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x7D,0xFE,0x7C,0x39,
-  0xFF,0xFF,0xF7,0xFF,0xEF,0xFF,0xFF,0xDF,0xFF,0xBF,0xFF,0x7F,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xDF,0xFF,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFE,0xFF,0xFF,0xFE,0xFF,0xFD,
-  0xBB,0x01,0xC7,0x83,0xC7,0x83,0xC7,0x83,0xBB,0x01,0x7C,0x39,0x7D,0xFE,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFD,0xFF,0xFF,0xFF,0xFF,0xFF,0x7F,
-  0xFF,0xFF,0xFF,0xFF,0xFD,0xFF,0xFF,0xFE,0xFF,0xFF,0xFF,0x7F,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFD,0xFF,0xFF,0xFB,0xAF,0x77,0x27,0x8F,0xDF,0x8F,0x27,0x8F,
-
-  /* Tile 0x10 */
-  0xFF,0xFF,0xFF,0xFE,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFB,0xFF,0xF7,0xEF,0xFF,0xDF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x7F,0xFF,0xFF,0xFB,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xBF,0xFF,0xDF,0xEF,0xFF,0xF7,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFD,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFE,0xFD,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-  0xAF,0x77,0xFF,0xFB,0xFD,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFD,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFB,0xFF,
-
-  /* Tile 0x18 */
-  0xFF,0xFF,0xFF,0xFF,0xFE,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x7F,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xF7,0xFF,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFB,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFE,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFE,0xFF,0x7D,0xFE,0x7C,0x39,
-  0xFF,0xFF,0xF7,0xFF,0xEF,0xFF,0xFF,0xDF,0xFF,0xBF,0xFF,0x7F,0x7F,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xBF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFD,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xEF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x7F,0xFD,
-
-  /* Tile 0x20 */
-  0xFF,0xFF,0xDF,0xFF,0xEF,0xFF,0xFF,0xF7,0xFF,0xFB,0xFE,0xFD,0xFD,0xFE,0xFE,0xFF,
-  0xAB,0x11,0xC7,0x83,0x83,0xC7,0xC7,0x83,0xAB,0x11,0x7C,0x39,0x7D,0xFE,0xFE,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFB,0xDF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x7F,0xFF,0xFF,0x7F,
-  0xFB,0xFF,0xFF,0xFD,0xFE,0xFE,0xFE,0xFF,0xFE,0xFE,0xFF,0xFD,0xFB,0xFF,0xFF,0xFF,
-  0xEF,0xFF,0xFF,0xDF,0x3F,0xBF,0x3F,0x7F,0x3F,0xBF,0xFF,0xDF,0xEF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xEF,0xFB,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFE,0xFF,0xFD,0xFE,0xFE,0xFD,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFB,0xFF,0xFF,
-
-  /* Tile 0x28 */
-  0xF7,0xFF,0xFB,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xBF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFE,0xFE,0xFF,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFD,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
-  0xFF,0xFF,0xFF,0xFF,0x7F,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF
-};
-
-/*
- * Image size: 0x40 x 0x40
- * Number of tiles (total - unique): 0x40 - 0x2D
- */
-
-const unsigned char bkg_tiles[] = {
-  0x00,0x01,0x02,0x03,0xFC,0xFC,0x04,0xFC,
-  0xFC,0x05,0x06,0xFC,0x07,0x08,0x09,0x0A,
-  0xFC,0xFC,0xFC,0x02,0x0B,0x0C,0x0D,0xFC,
-  0x0E,0x0F,0x10,0xFC,0x11,0x12,0x13,0x14,
-  0x15,0x16,0x17,0xFC,0x18,0x19,0x1A,0xFC,
-  0x1B,0x1C,0x1D,0xFC,0xFC,0x1E,0x1F,0x20,
-  0x21,0x22,0xFC,0x23,0x24,0x25,0xFC,0x26,
-  0x27,0x13,0x28,0x29,0x2A,0x2B,0x2C,0x11
-};
-
-/*
- * Image size: 0x10 x 0x70
- * Number of tiles (total - unique): 0x1C - 0x1C
- */
-
-const unsigned char earth_tiles[] = {
-  0x00,0x02,
-  0x04,0x06,
-  0x08,0x0A,
-  0x0C,0x0E,
-  0x10,0x12,
-  0x14,0x16,
-  0x18,0x1A
-};
-
-/*
- * Image size: 0x80 x 0x50
- * Number of tiles (total - unique): 0xA0 - 0x15
- */
-
-const unsigned char frame_tiles[] = {
-  0x80,0x81,0xFD,0x82,0x83,0x81,0xFD,0x82,0x83,0x81,0xFD,0x82,0x83,0x81,0xFD,0x84,
-  0x85,0x86,0x87,0x88,0x89,0x8A,0x87,0x88,0x89,0x8A,0x87,0x88,0x89,0x8A,0x8B,0x8C,
-  0xFD,0x8D,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x8E,0x8F,
-  0x82,0x8C,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x85,0x90,
-  0x8E,0x8F,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFD,0x8D,
-  0x85,0x90,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x82,0x8C,
-  0xFD,0x8D,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x8E,0x8F,
-  0x82,0x8C,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x85,0x90,
-  0x8E,0x91,0xFD,0x82,0x83,0x81,0xFD,0x82,0x83,0x81,0xFD,0x82,0x83,0x81,0x92,0x8D,
-  0x93,0x8A,0x87,0x88,0x89,0x8A,0x87,0x88,0x89,0x8A,0x87,0x88,0x89,0x8A,0x87,0x94
-};
-
-/*
- * Image size: 0x60 x 0x30
- * Number of tiles (total - unique): 0x48 - 0x03
- */
-
-const unsigned char door1_tiles[] = {
-  0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,
-  0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,
-  0x97,0x97,0x97,0x97,0x97,0x97,0x97,0x97,0x97,0x97,0x97,0x97,
-  0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,
-  0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,
-  0x97,0x97,0x97,0x97,0x97,0x97,0x97,0x97,0x97,0x97,0x97,0x97,
-
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC
-};
-
-/*
- * Image size: 0x60 x 0x30
- * Number of tiles (total - unique): 0x48 - 0x04
- */
-
-const unsigned char door2_tiles[] = {
-  0x98,0x98,0x98,0x98,0x98,0x98,0x98,0x98,0x98,0x98,0x98,0x98,
-  0x99,0x99,0x99,0x99,0x99,0x99,0x99,0x99,0x99,0x99,0x99,0x99,
-  0x9A,0x9A,0x9A,0x9A,0x9A,0x9A,0x9A,0x9A,0x9A,0x9A,0x9A,0x9A,
-  0x98,0x98,0x98,0x98,0x98,0x98,0x98,0x98,0x98,0x98,0x98,0x98,
-  0x99,0x99,0x99,0x99,0x99,0x99,0x99,0x99,0x99,0x99,0x99,0x99,
-  0x9B,0x9B,0x9B,0x9B,0x9B,0x9B,0x9B,0x9B,0x9B,0x9B,0x9B,0x9B,
-
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,
-};
-
-/*
- * Image size: 0x60 x 0x30
- * Number of tiles (total - unique): 0x48 - 0x04
- */
-
-const unsigned char door3_tiles[] = {
-  0x9C,0x9C,0x9C,0x9C,0x9C,0x9C,0x9C,0x9C,0x9C,0x9C,0x9C,0x9C,
-  0x9D,0x9D,0x9D,0x9D,0x9D,0x9D,0x9D,0x9D,0x9D,0x9D,0x9D,0x9D,
-  0x9E,0x9E,0x9E,0x9E,0x9E,0x9E,0x9E,0x9E,0x9E,0x9E,0x9E,0x9E,
-  0x9C,0x9C,0x9C,0x9C,0x9C,0x9C,0x9C,0x9C,0x9C,0x9C,0x9C,0x9C,
-  0x9D,0x9D,0x9D,0x9D,0x9D,0x9D,0x9D,0x9D,0x9D,0x9D,0x9D,0x9D,
-  0x9F,0x9F,0x9F,0x9F,0x9F,0x9F,0x9F,0x9F,0x9F,0x9F,0x9F,0x9F,
-
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC
-};
-
-/*
- * Image size: 0x60 x 0x30
- * Number of tiles (total - unique): 0x48 - 0x01
- */
-
-const unsigned char door4_tiles[] = {
-  0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,
-  0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,
-  0x97,0x97,0x97,0x97,0x97,0x97,0x97,0x97,0x97,0x97,0x97,0x97,
-  0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,0x95,
-  0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,0x96,
-  0xA0,0xA0,0xA0,0xA0,0xA0,0xA0,0xA0,0xA0,0xA0,0xA0,0xA0,0xA0,
-
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,
-  0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC,0xFC
-};
-
-/* Should really be const, but sdcc doesnt yet support it. */
-const unsigned char * const film[] = {
-  &door1_tiles[0x0C*0],
-  &door2_tiles[0x0C*0],
-  &door3_tiles[0x0C*0],
-  &door4_tiles[0x0C*0],
-  &door1_tiles[0x0C*1],
-  &door2_tiles[0x0C*1],
-  &door3_tiles[0x0C*1],
-  &door4_tiles[0x0C*1],
-  &door1_tiles[0x0C*2],
-  &door2_tiles[0x0C*2],
-  &door3_tiles[0x0C*2],
-  &door4_tiles[0x0C*2],
-  &door1_tiles[0x0C*3],
-  &door2_tiles[0x0C*3],
-  &door3_tiles[0x0C*3],
-  &door4_tiles[0x0C*3],
-  &door1_tiles[0x0C*4],
-  &door2_tiles[0x0C*4],
-  &door3_tiles[0x0C*4],
-  &door4_tiles[0x0C*4],
-  &door1_tiles[0x0C*5],
-  &door2_tiles[0x0C*5],
-  &door3_tiles[0x0C*5],
-  &door4_tiles[0x0C*5],
-  &door1_tiles[0x0C*6]
-};
-
-#define NBDFRAMES 0x18                  /* Nb frames for the door */
-#define NBSFRAMES 0x07                  /* Nb frames for the sprite */
-#define WINSZX    0x80                  /* Size of the picture in the window */
-#define WINSZY    0x50
-#define MINWINX   (MAXWNDPOSX-WINSZX+1) /* Bounds of the window origin */
-#define MINWINY   (MAXWNDPOSY-WINSZY+1)
-#define MAXWINX   MAXWNDPOSX
-#define MAXWINY   MAXWNDPOSY
-#define FADESTEP  0x10                  /* Nb steps for the fading effect */
-#define STARTFADE (0x06*FADESTEP)       /* Initial value for the fading effect */
-
-#define CLOSED  0x00
-#define OPENING 0x01
-#define OPENED  0x02
-#define CLOSING 0x03
-
-static uint8_t time = 0;  /* Global "time" value (counter) */
-uint8_t doorstate = 0;    /* State of the door (OPENED, CLOSED...) */
-uint8_t doorpos = 0;      /* Current position in the door animation */
-static uint8_t color = 0; /* Current color for fading effect */
-uint8_t sframe = 0;       /* Current frame of the sprite */
-fixed bposx, bposy; /* Background position (fixed point) */
-fixed bspx, bspy;   /* Background speed (fixed point) */
-fixed wposx, wposy; /* Window position (fixed point) */
-fixed wspx, wspy;   /* Window speed (fixed point) */
-fixed sposx, sposy; /* Sprite position (fixed point) */
-fixed sspx, sspy;   /* Sprite speed (fixed point) */
-
-void fade(void);
-void scroll(void);
-void door(void);
-void animate_sprite(void);
-void tile_sprite(void);
-void place_sprite(void);
-
-/* Fade the screen (off and on) */
-void fade(void)
-{
-  if(color == 0)
-    return;
-  switch(color)
-    {
-    case STARTFADE:
-    case STARTFADE-4*FADESTEP:
-      BGP_REG = 0xF9U;
-      break;
-    case STARTFADE-FADESTEP:
-    case STARTFADE-3*FADESTEP:
-      BGP_REG = 0xFEU;
-      break;
-    case STARTFADE-2*FADESTEP:
-      BGP_REG = 0xFFU;
-      break;
-    case STARTFADE-5*FADESTEP:
-      BGP_REG = 0xE4U;
-      break;
-    }
-  color--;
-}
-
-/* Scroll the background, the window and the sprite */
-void scroll(void)
-{
-  /* Update background */
-  bposx.w += bspx.w;
-  bposy.w += bspy.w;
-  SCX_REG = bposx.b.h;
-  SCY_REG = bposy.b.h;
-
-  /* Update window */
-  wposx.w += wspx.w ;
-  wposy.w += wspy.w ;
-  /* X position */
-  if(wposx.b.h >= MAXWINX) {
-    wposx.b.h = MAXWINX;
-    /* Invert speed */
-    wspx.w = -(int16_t)wspx.w;
-  } else if(wposx.b.h <= MINWINX) {
-    wposx.b.h = MINWINX;
-    /* Invert speed */
-    wspx.w = -(int16_t)wspx.w;
-  }
-  WX_REG = wposx.b.h;
-  /* Y position */
-  if(wposy.b.h >= MAXWINY) {
-    wposy.b.h = MAXWINY;
-    /* Invert speed */
-    wspy.w = -(int16_t)wspy.w;
-  } else if(wposy.b.h <= MINWINY) {
-    wposy.b.h = MINWINY;
-    /* Invert speed */
-    wspy.w = -(int16_t)wspy.w;
-  }
-  WY_REG = wposy.b.h;
-
-  /* Update sprite */
-  sposx.w += sspx.w;
-  sposy.w += sspy.w;
-  place_sprite();
-}
-
-/* Open and close the door */
-void door(void)
-{
-  if(doorstate == OPENING) {
-    doorpos++;
-    /* Draw the door in the window */
-    set_win_tiles(2, 2, 12, 6, (unsigned char*)film[doorpos]);
-    if(doorpos == NBDFRAMES)
-      doorstate = OPENED;
-  } else if(doorstate == CLOSING) {
-    doorpos--;
-    /* Draw the door in the window */
-    set_win_tiles(2, 2, 12, 6, (unsigned char*)film[doorpos]);
-    if(doorpos == 0)
-      doorstate = CLOSED;
-  }
-}
-
-/* Animate sprite */
-void animate_sprite(void)
-{
-  if((time&0x07) == 0) {
-    sframe++;
-    if(sframe == NBSFRAMES)
-      sframe = 0;
-    tile_sprite();
-  }
-}
-
-/* Set sprite tiles */
-void tile_sprite(void)
-{
-  uint8_t s;
-
-  s = sframe<<1;
-  set_sprite_tile(0, earth_tiles[s]);
-  set_sprite_tile(1, earth_tiles[s+1]);
-}
-
-/* Place sprite */
-void place_sprite(void)
-{
-  move_sprite(0, sposx.b.h, sposy.b.h);
-  move_sprite(1, sposx.b.h+8, sposy.b.h);
-}
-
-void main(void)
-{
-  uint8_t i, j;
-
-  disable_interrupts();
-  DISPLAY_OFF;
-  LCDC_REG = LCDCF_OFF | LCDCF_WIN9C00 | LCDCF_WINON | LCDCF_BG8800 | LCDCF_BG9800 | LCDCF_OBJ16 | LCDCF_OBJON | LCDCF_BGON;
-  /*
-   * LCD        = Off
-   * WindowBank = 0x9C00
-   * Window     = On
-   * BG Chr     = 0x8800
-   * BG Bank    = 0x9800
-   * OBJ        = 8x16
-   * OBJ        = On
-   * BG         = On
-   */
-
-  doorstate = CLOSED;
-
-  /* Set palettes */
-  BGP_REG = OBP0_REG = OBP1_REG = 0xE4U;
-
-  /* Initialize the background */
-  set_bkg_data(0xFC, 0x04, std_data);
-  set_bkg_data(0x00, 0x2D, bkg_data);
-  /*
-   * Draw the background
-   *
-   * Width  = 0x100 = 0x20 * 8
-   * Height = 0x100 = 0x20 * 8
-   */
-  for(i = 0; i < 32; i+=8)
-    for(j = 0; j < 32; j+=8)
-      set_bkg_tiles(i, j, 8, 8, bkg_tiles);
-  bposx.w = 0;
-  SCX_REG = 0;
-  bposy.w = 0;
-  SCY_REG = 0;
-  bspx.w = 0xFF00;
-  bspy.w = 0x0080;
-
-  /* Initialize the window */
-  set_win_data(0x80, 0x21, frame_data);
-  /*
-   * Draw the frame in the window
-   *
-   * Width  = 0x80 = 0x10 * 8
-   * Height = 0x50 = 0x0A * 8
-   */
-  set_win_tiles(0, 0, 16, 10, frame_tiles);
-  /*
-   * Draw the door in the window
-   *
-   * Width  = 0x60 = 0x20 * 12
-   * Height = 0x30 = 0x20 * 6
-   */
-  set_win_tiles(2, 2, 12, 6, door1_tiles);
-  wposx.b.h = MAXWNDPOSX;
-  wposx.b.l = 0;
-  WX_REG = MAXWNDPOSX;
-  wposy.b.h = MAXWNDPOSY;
-  wposy.b.l = 0;
-  WY_REG = MAXWNDPOSY;
-  wspx.w = 0xFF80;
-  wspy.w = 0xFFC0;
-
-  /* Initialize the sprite */
-  set_sprite_data(0x00, 0x1C, earth_data);
-  set_sprite_prop(0, 0x00);
-  set_sprite_prop(1, 0x00);
-  sframe = 0;
-  sposx.w  = 0x1000;
-  sposy.w  = 0x1000;
-  sspx.w  = 0x0040;
-  sspy.w  = 0x0040;
-  tile_sprite();
-  place_sprite();
-
-  DISPLAY_ON;
-  enable_interrupts();
-
-  while(1) {
-    /* Skip four VBLs (slow down animation) */
-    for(i = 0; i < 4; i++)
-      vsync();
-    time++;
-    fade();
-    door();
-    scroll();
-    animate_sprite();
-    i = joypad();
-    if(i & J_B) {
-      if(i & J_UP)
-	bspy.w -= 0x0010;
-      if(i & J_DOWN)
-	bspy.w += 0x0010;
-      if(i & J_LEFT)
-	bspx.w -= 0x0010;
-      if(i & J_RIGHT)
-	bspx.w += 0x0010;
-    } else if(i & J_A) {
-      if(i & J_UP)
-	wspy.w -= 0x0010;
-      if(i & J_DOWN)
-	wspy.w += 0x0010;
-      if(i & J_LEFT)
-	wspx.w -= 0x0010;
-      if(i & J_RIGHT)
-	wspx.w += 0x0010;
-    } else {
-      if(i & J_SELECT)
-	color = STARTFADE;
-      if(i & J_START)
-	if(doorstate == CLOSED) {
-	  doorstate = OPENING;
-	  doorpos = 0;
-	} else if(doorstate == OPENED) {
-	  doorstate = CLOSING;
-	  doorpos = NBDFRAMES;
-	}
-      if(i & J_UP)
-	sspy.w -= 0x0010;
-      if(i & J_DOWN)
-	sspy.w += 0x0010;
-      if(i & J_LEFT)
-	sspx.w -= 0x0010;
-      if(i & J_RIGHT)
-	sspx.w += 0x0010;
-    }
-  }
-}

src/main.c

+#include <gbdk/platform.h>
+#include <gbdk/metasprites.h>
+
+#include "rockshp.h"
+
+#define TILE_WIDTH          8
+#define TILE_HEIGHT         8
+#define NUM_BYTES_PER_TILE  16
+
+#define ACC_X 1
+#define ACC_Y 2
+
+// The metasprite will be built starting with hardware sprite zero (the first)
+#define SPR_NUM_START 0
+
+// Metasprite tiles are loaded into VRAM starting at tile number 0
+#define TILE_NUM_START 0
+
+int16_t PosX, PosY;
+int16_t SpdX, SpdY;
+uint8_t PosF;
+uint8_t idx, rot;
+
+size_t num_tiles;
+uint8_t flipped_data[NUM_BYTES_PER_TILE];
+
+uint8_t joyp = 0, old_joyp = 0;
+
+#define KEY_INPUT (old_joyp = joyp, joyp = joypad())
+#define KEY_DOWN(KEY) (joyp & (KEY))
+#define KEY_PRESSED(KEY) ((joyp ^ old_joyp) & joyp & (KEY))
+
+// Table for fast reversing of bits in a byte - used for flipping in X
+const uint8_t reverse_bits[256] = {
+    0x00,0x80,0x40,0xC0,0x20,0xA0,0x60,0xE0,0x10,0x90,0x50,0xD0,0x30,0xB0,0x70,0xF0,
+    0x08,0x88,0x48,0xC8,0x28,0xA8,0x68,0xE8,0x18,0x98,0x58,0xD8,0x38,0xB8,0x78,0xF8,
+    0x04,0x84,0x44,0xC4,0x24,0xA4,0x64,0xE4,0x14,0x94,0x54,0xD4,0x34,0xB4,0x74,0xF4,
+    0x0C,0x8C,0x4C,0xCC,0x2C,0xAC,0x6C,0xEC,0x1C,0x9C,0x5C,0xDC,0x3C,0xBC,0x7C,0xFC,
+    0x02,0x82,0x42,0xC2,0x22,0xA2,0x62,0xE2,0x12,0x92,0x52,0xD2,0x32,0xB2,0x72,0xF2,
+    0x0A,0x8A,0x4A,0xCA,0x2A,0xAA,0x6A,0xEA,0x1A,0x9A,0x5A,0xDA,0x3A,0xBA,0x7A,0xFA,
+    0x06,0x86,0x46,0xC6,0x26,0xA6,0x66,0xE6,0x16,0x96,0x56,0xD6,0x36,0xB6,0x76,0xF6,
+    0x0E,0x8E,0x4E,0xCE,0x2E,0xAE,0x6E,0xEE,0x1E,0x9E,0x5E,0xDE,0x3E,0xBE,0x7E,0xFE,
+    0x01,0x81,0x41,0xC1,0x21,0xA1,0x61,0xE1,0x11,0x91,0x51,0xD1,0x31,0xB1,0x71,0xF1,
+    0x09,0x89,0x49,0xC9,0x29,0xA9,0x69,0xE9,0x19,0x99,0x59,0xD9,0x39,0xB9,0x79,0xF9,
+    0x05,0x85,0x45,0xC5,0x25,0xA5,0x65,0xE5,0x15,0x95,0x55,0xD5,0x35,0xB5,0x75,0xF5,
+    0x0D,0x8D,0x4D,0xCD,0x2D,0xAD,0x6D,0xED,0x1D,0x9D,0x5D,0xDD,0x3D,0xBD,0x7D,0xFD,
+    0x03,0x83,0x43,0xC3,0x23,0xA3,0x63,0xE3,0x13,0x93,0x53,0xD3,0x33,0xB3,0x73,0xF3,
+    0x0B,0x8B,0x4B,0xCB,0x2B,0xAB,0x6B,0xEB,0x1B,0x9B,0x5B,0xDB,0x3B,0xBB,0x7B,0xFB,
+    0x07,0x87,0x47,0xC7,0x27,0xA7,0x67,0xE7,0x17,0x97,0x57,0xD7,0x37,0xB7,0x77,0xF7,
+    0x0F,0x8F,0x4F,0xCF,0x2F,0xAF,0x6F,0xEF,0x1F,0x9F,0x5F,0xDF,0x3F,0xBF,0x7F,0xFF
+};
+
+void set_tile(uint8_t tile_idx, uint8_t* data, uint8_t flip_x, uint8_t flip_y)
+{
+    size_t i;
+    for(i = 0; i < TILE_HEIGHT; i++)
+    {
+        size_t y = flip_y ? (TILE_HEIGHT-1-i) : i;
+        flipped_data[2*i] = flip_x ? reverse_bits[data[2*y]] : data[2*y];
+        flipped_data[2*i+1] = flip_x ? reverse_bits[data[2*y+1]] : data[2*y+1];
+    }
+    set_sprite_data(tile_idx, 1, flipped_data);
+}
+
+uint8_t get_tile_offset(uint8_t flipx, uint8_t flipy)
+{
+    flipx; flipy; // suppress compiler warnings
+    uint8_t offset = 0;
+    #if !HARDWARE_SPRITE_CAN_FLIP_Y
+    offset += flipy ? num_tiles : 0;
+    #endif
+    #if !HARDWARE_SPRITE_CAN_FLIP_X
+    offset <<= 1;
+    offset += flipx ? num_tiles : 0;
+    #endif
+    return offset;
+}
+
+void main(void) {
+    DISPLAY_OFF;
+
+    set_default_palette();
+
+    size_t i;
+    num_tiles = sizeof(rockshp_tiles) >> 4;
+    for(i = 0; i < num_tiles; i++)
+    {
+        set_tile(i + get_tile_offset(0, 0), rockshp_tiles + (i << 4), 0, 0);
+    }
+
+    // Show bkg and sprites
+    SHOW_BKG; SHOW_SPRITES;
+
+    // Check what size hardware sprite the metasprite is using (from sprite.h)
+    #if sprite_TILE_H == 16
+    SPRITES_8x16;
+    #else
+    SPRITES_8x8;
+    #endif
+    DISPLAY_ON;
+
+    // Set initial position to the center of the screen, zero out speed
+    PosX = (DEVICE_SCREEN_PX_WIDTH / 2) << 4;
+    PosY = (DEVICE_SCREEN_PX_HEIGHT / 2) << 4;
+    SpdX = SpdY = 0;
+
+    idx = 0; rot = 0;
+
+    while(1) {
+        KEY_INPUT;
+
+        PosF = 0;
+        // Game object
+        if (KEY_DOWN(J_UP)) {
+            SpdY -= 2;
+            if (SpdY < -32) SpdY = -32;
+            PosF |= ACC_Y;
+        } else if (KEY_DOWN(J_DOWN)) {
+            SpdY += 2;
+            if (SpdY > 32) SpdY = 32;
+            PosF |= ACC_Y;
+        }
+
+        if (KEY_DOWN(J_LEFT)) {
+            SpdX -= 2;
+            if (SpdX < -32) SpdX = -32;
+            PosF |= ACC_X;
+        } else if (KEY_DOWN(J_RIGHT)) {
+            SpdX += 2;
+            if (SpdX > 32) SpdX = 32;
+            PosF |= ACC_X;
+        }
+
+        // Press B button to cycle through metasprite animations
+        if (KEY_PRESSED(J_B)) {
+            idx++; if (idx >= (sizeof(rockshp_metasprites) >> 1)) idx = 0;
+        }
+
+        // Press A button to cycle metasprite through Normal/Flip-Y/Flip-XY/Flip-X and sub-pals
+        if (KEY_PRESSED(J_A)) {
+            rot++; rot &= 0xF;
+        }
+
+        PosX += SpdX, PosY += SpdY;
+
+        uint8_t hiwater = SPR_NUM_START;
+
+        // NOTE: In a real game it would be better to only call the move_metasprite..()
+        //       functions if something changed (such as movement or rotation). That
+        //       reduces CPU usage on frames that don't need updates.
+        //
+        // In this example they are called every frame to simplify the example code
+
+        // If not hidden the move and apply rotation to the metasprite
+        uint8_t subpal = rot >> 2;
+        switch (rot & 0x3) {
+            case 1:
+                hiwater += move_metasprite_flipy( rockshp_metasprites[idx],
+                                                  TILE_NUM_START + get_tile_offset(0, 1),
+                                                  subpal,
+                                                  hiwater,
+                                                  DEVICE_SPRITE_PX_OFFSET_X + (PosX >> 4),
+                                                  DEVICE_SPRITE_PX_OFFSET_Y + (PosY >> 4));
+                break;
+            case 2:
+                hiwater += move_metasprite_flipxy(rockshp_metasprites[idx],
+                                                  TILE_NUM_START + get_tile_offset(1, 1),
+                                                  subpal,
+                                                  hiwater,
+                                                  DEVICE_SPRITE_PX_OFFSET_X + (PosX >> 4),
+                                                  DEVICE_SPRITE_PX_OFFSET_Y + (PosY >> 4));
+                break;
+            case 3:
+                hiwater += move_metasprite_flipx( rockshp_metasprites[idx],
+                                                  TILE_NUM_START + get_tile_offset(1, 0),
+                                                  subpal,
+                                                  hiwater,
+                                                  DEVICE_SPRITE_PX_OFFSET_X + (PosX >> 4),
+                                                  DEVICE_SPRITE_PX_OFFSET_Y + (PosY >> 4));
+                break;
+            default:
+                hiwater += move_metasprite_ex(    rockshp_metasprites[idx],
+                                                  TILE_NUM_START + get_tile_offset(0, 0),
+                                                  subpal,
+                                                  hiwater,
+                                                  DEVICE_SPRITE_PX_OFFSET_X + (PosX >> 4),
+                                                  DEVICE_SPRITE_PX_OFFSET_Y + (PosY >> 4));
+                break;
+        }
+
+        // Hide rest of the hardware sprites, because amount of sprites differ between animation frames.
+        hide_sprites_range(hiwater, MAX_HARDWARE_SPRITES);
+
+        // Y Axis: update velocity (reduce speed) if no U/D button pressed
+        if (!(PosF & ACC_Y)) {
+            if (SpdY != 0) {
+                if (SpdY > 0) SpdY--;
+                else SpdY ++;
+            }
+        }
+
+        // X Axis: update velocity (reduce speed) if no L/R button pressed
+        if (!(PosF & ACC_X)) {
+            if (SpdX != 0) {
+                if (SpdX > 0) SpdX--;
+                else SpdX ++;
+            }
+        }
+
+        vsync();
+    }
+}