網 路上有很多文章在講解如何將SDL整合到Android的平台上，我自己也試著動手做看看，順便將一些步驟及心得整理起來。以下是這次我所用到的開發環境。- Cygwin- Android NDK：android-ndk-r4b-windows- SDL：1.2.14《Step 1》將SDL中的Makefile.minimal修改如下 (紅體字) ：# Makefile to build the SDL libraryPREBUILT = /android-ndk-r4b/build/prebuilt/windows/arm-eabi-4.4.0INCLUDE = -I./include -I/android-ndk-r4b/build/platforms/android-8/arch-arm/usr/includeCFLAGS = -g -O2 $(INCLUDE)CC = $(PREBUILT)/bin/arm-eabi-gccAR = $(PREBUILT)/bin/arm-eabi-arRANLIB = $(PREBUILT)/bin/arm-eabi-ranlibCONFIG_H = include/SDL_config.hTARGET = libSDL.aSOURCES = / src/*.c / src/audio/*.c / src/cdrom/*.c / src/cpuinfo/*.c / src/events/*.c / src/file/*.c / src/joystick/*.c / src/stdlib/*.c / src/thread/*.c / src/timer/*.c / src/video/*.c / src/audio/dsp/*.c / src/audio/dma/*.c / src/video/fbcon/*.c / src/joystick/dummy/*.c / src/cdrom/dummy/*.c / src/thread/generic/*.c / src/timer/unix/*.c / src/loadso/dummy/*.c /OBJECTS = $(shell echo $(SOURCES) | sed -e 's,/.c,/.o,g')all: $(TARGET)$(TARGET): $(CONFIG_H) $(OBJECTS) $(AR) crv $@ $^ $(RANLIB) $@$(CONFIG_H): cp $(CONFIG_H).default $(CONFIG_H)clean: rm -f $(TARGET) $(OBJECTS)《Step 2》修改 ./include/SDL_config_minimal.h (紅體字) ：#ifndef _SDL_config_minimal_h#define _SDL_config_minimal_h#include "SDL_platform.h"/* This is the minimal configuration that can be used to build SDL */#include <stdarg.h>typedef signed char int8_t;typedef unsigned char uint8_t;typedef signed short int16_t;typedef unsigned short uint16_t;typedef signed int int32_t;typedef unsigned int uint32_t;typedef unsigned int size_t;typedef unsigned long uintptr_t;#define SDL_AUDIO_DRIVER_OSS 1#define SDL_CDROM_DISABLED 1#define SDL_JOYSTICK_DISABLED 1#define SDL_LOADSO_DISABLED 1#define SDL_THREADS_DISABLED 1#define SDL_TIMER_UNIX 1#define SDL_VIDEO_DRIVER_FBCON 1#define HAVE_STDIO_H 1#endif /* _SDL_config_minimal_h */《Step 3》由於Android的framebuffer設 備是 /dev/graphics/fb0 (Linux是 /dev/fb0)，所以我們需要修改 ./src/video/fbcon/SDL_fbvideo.c。將檔案中所有的/dev/fb0全都置換成/dev/graphics/fb0《Step 4》開始編譯 libSDL.a，在 Cygwin下進入SDL的根目錄，輸入make -f Makefile.minimal《Step 4.1》make 的過程中會遇到一些compile error，我們一步步來解決它們。首先，compiler會告訴我們某些變數已經 (在SDL_config_minimal.h) 重覆定義了：/android-ndk-r4b/build/platforms/android-8/arch-arm/usr/include/stdint.h:53: error: redefinition of typedef 'int8_t'./include/SDL_config_minimal.h:32: note: previous declaration of 'int8_t' was here解決 的辦法是將SDL_config_minimal.h中重覆定義的部分mark起來 (紅體字)：//typedef signed char int8_t;//typedef unsigned char uint8_t;//typedef signed short int16_t;//typedef unsigned short uint16_t;//typedef signed int int32_t;//typedef unsigned int uint32_t;//typedef unsigned int size_t;//typedef unsigned long uintptr_t;《Step 4.2》接 著，compiler認為SDL_dummy_enum的size不合法：./include/SDL_stdinc.h:151: error: size of array 'SDL_dummy_enum' is negative在 這邊，我將SDL_stdinc.h的151行mark起來 (紅體字)：//SDL_COMPILE_TIME_ASSERT(enum, sizeof(SDL_DUMMY_ENUM) == sizeof(int));《Step 4.3》最後會遇到的error是找不到soundcard.h：src/audio/dsp/SDL_dspaudio.c:44:27: error: sys/soundcard.h: No such file or directory因 為sys/soundcard.h指的是/cygwin/usr/include下的header檔，所以我們要回到Makefile.minimal中 的INCLUDE，將該路徑告訴compiler (紅體字)：INCLUDE = -I./include -I/android-ndk-r4b/build/platforms/android-8/arch-arm/usr/include -I/usr/include修 改完之後再重新make。《Step 5》成功，在SDL的 根目錄下產生libSDL.a
