代码结构
所有代码都已通过测试跑通，其中代码结构如下：
一、include文件夹
1.1 common.h
#ifndef _COMMON_H
#define _COMMON_H
typedef struct Region {
int iLeftUpX; //区域左上方的坐标
int iLeftUpY; //区域左下方的坐标
int iWidth; //区域宽度
int iHeigh; //区域高度
}Region, *PRegion;
#endif1.2 disp_manager.h
#ifndef _DISP_MANAGER_H //防止头文件重复包含,只要右边的出现过，就不会再往下编译
#define _DISP_MANAGER_H
#include<common.h>
//区域结构体
typedef struct DispBuff {
int iXres;
int iYres;
int iBpp;
char *buff;
}DispBuff, *PDispBuff;
//区域结构体
/*
typedef struct Region {
int iLeftUpX; //区域左上方的坐标
int iLeftUpY; //区域左下方的坐标
int iWidth; //区域宽度
int iHeigh; //区域高度
}Region, *PRegion;
*/
//显示设备结构体（LCD设备或者是web设备），通过调用这个结构体中的函数来实现显示功能
typedef struct DispOpr {
char *name; //设备名
int (*DeviceInit)(void);//设备初始化函数
int (*DeviceExit)(void);//设备清除
int (*GetBuffer)(PDispBuff ptDispBuff);///用于获取lcd所需的内存空间，return内存空间的首地址
//argument1-lcd屏长度，argument2-lcd屏宽度，argument3-每一个像素点的位数。
int (*FlushRegion)(PRegion ptRegion, PDispBuff ptDispBuff);//刷新出argum1-按钮区域，argum2-区域数据
struct DispOpr *ptNext;//结构体指针，指向下一个设备机构体 多设备输出
}DispOpr,*PDispOpr;
void RegisterDisplay(PDispOpr ptDispOpr);
void DisplayInit(void);
int SelectDefaultDisplay(char *name);
int InitDefaultDisplay(void);
int PutPixel(int x, int y, unsigned int dwColor);
int FlushDisplayRegion(PRegion ptRegion, PDispBuff ptDispBuff);
PDispBuff GetDisplayBuffer(void);
void DrawRegion(PRegion ptRegion, unsigned int dwColor);
void DrawTextInRegionCentral(char *name, PRegion ptRegion, unsigned int dwColor);
#endif1.3 font_manager.h
#ifndef _FONT_MANAGER_H
#define _FONT_MANAGER_H
#include <common.h>
//描述字体位图
typedef struct FontBitMap {
Region tRegion;
int iCurOriginX;//当期字符基点x坐标
int iCurOriginY;//当期字符基点y坐标
int iNextOriginX;//下一个字符基点x坐标
int iNextOriginY;//下一个字符基点y坐标
unsigned char *pucBuffer;
}FontBitMap, *PFontBitMap;
//描述字库操作
typedef struct FontOpr {
char *name;
int (*FontInit)(char *aFineName);//字体初始化
int (*SetFontSize)(int iFontSize);//字体大小
int (*GetFontBitMap)(unsigned int dwCode, PFontBitMap ptFontBitMap);//获得字符位图，存到ptFontBitMap中
struct FontOpr *ptNext;//方便支持多种字库
}FontOpr, *PFontOpr;
void RegisterFont(PFontOpr ptFontOpr);
void FontsRegister(void);
int SelectAndInitFont(char *aFontOprName, char *aFontFileName);
int SetFontSize(int iFontSize);
int GetFontBitMap(unsigned int dwCode, PFontBitMap ptFontBitMap);
#endif
1.4 input_manager.h
#ifndef _INPUT_MANAGER_H //防止头文件重复包含,只要右边的出现过，就不会再往下编译
#define _INPUT_MANAGER_H
#include <sys/time.h>
#define INPUT_TYPE_TOUCH 1
#define INPUT_TYPE_NET 2
/* 上报的数据格式 */
typedef struct InputEvent
{
struct timeval tTime; //加入时间管理
int iType; //网络事件或者触摸事件类型
int iX; //触摸事件x坐标
int iY; //触摸事件y坐标
int iPressure; //触摸事件压力
char str[1024]; //网络事件字符串
} InputEvent, *PInputEvent;
/* 不同的输入设备，应该模块化，使用下面的结构体表示输入设备 */
typedef struct InputDevice
{
char *name; //设备名称
int (*GetInputEvent)(PInputEvent ptInputEvent); //获得数据
int (*DeviceInit)(void);
int (*DeviceExit)(void);
struct InputDevice *ptNext; //加入链表，将多个输入设备链接到一起
} InputDevice, *PInputDevice;
#endif1.5 ui.h
#ifndef _UI_H_
#define _UI_H_
#include<common.h>
#include<disp_manager.h>
#include<input_manager.h>
#define BUTTON_DEFAULT_COLOR 0xff0000
#define BUTTON_PRESSED_COLOR 0x00ff00
#define BUTTON_TEXT_COLOR 0x000000
struct Button;
/* 函数指针（绘制按键） */
typedef int (*ONDRAW_FUNC)(struct Button *ptButton, PDispBuff ptDispBuff);
/* 函数指针（按下按钮） */
typedef int (*ONPRESSED_FUNC)(struct Button *ptButton, PDispBuff ptDispBuff, PInputEvent ptInputEvent);
typedef struct Button {
char *name; // 按键 名字
int status; //按键 按下状态
Region tRegion; // 按键的区域
ONDRAW_FUNC OnDraw; //一个 ONDRAW_FUNC 类型的函数指针，用于指向按钮绘制函数
ONPRESSED_FUNC OnPressed; //一个 ONPRESSED_FUNC 类型的函数指针，用于指向按钮按下事件处理函数
}Button, *PButton;
#endif二、button文件夹
2.1 button.c
#include<ui.h>
#include <string.h>
#include <disp_manager.h>
static int DefaultOnDraw(struct Button *ptButton, PDispBuff ptDispBuff){
/* 绘制底色 DrawRegion追加在disp_manager.c中 */
DrawRegion(&ptButton->tRegion, BUTTON_DEFAULT_COLOR); // 红色 0xff0000
/* 居中写文字 DrawTextInRegionCentral追加在disp_manager.c中*/
DrawTextInRegionCentral(ptButton->name, &ptButton->tRegion, BUTTON_TEXT_COLOR); //黑色 0x000000
/* flush to lcd/web */
FlushDisplayRegion(&ptButton->tRegion, ptDispBuff);
return 0;
}
static int DefaultOnPressed(struct Button *ptButton, PDispBuff ptDispBuff, PInputEvent ptInputEvent)
{
unsigned int dwColor = BUTTON_DEFAULT_COLOR;
ptButton->status = !ptButton->status;
if (ptButton->status)
dwColor = BUTTON_PRESSED_COLOR;
/* 绘制底色 */
DrawRegion(&ptButton->tRegion, dwColor);
/* 居中写文字 */
DrawTextInRegionCentral(ptButton->name, &ptButton->tRegion, BUTTON_TEXT_COLOR);
/* flush to lcd/web */
FlushDisplayRegion(&ptButton->tRegion, ptDispBuff);
return 0;
}
void InitButton(PButton ptButton, char *name, PRegion ptRegion, ONDRAW_FUNC OnDraw, ONPRESSED_FUNC OnPressed)
{
ptButton->status = 0; //初始状态为 0 ，未按下
ptButton->name = name;
ptButton->tRegion = *ptRegion; // 按钮的区域
ptButton->OnDraw = OnDraw ? OnDraw : DefaultOnDraw; //若 OnDraw 为空，则执行默认绘制函数DefaultOnDraw
ptButton->OnPressed = OnPressed ? OnPressed : DefaultOnPressed; //若 OnPressed 为空，则执行默认绘制函数DefaultOnPressed
}
2.2 Makefile
EXTRA_CFLAGS :=
CFLAGS_file.o :=
obj-y +=button.o
三、display文件夹
3.1 disp_manager.c
#include "disp_manager.h"
#include "font_manager.h"
#include <stdio.h>
#include <string.h>
//管理底层lcd和web
/* display_manager.c */
static PDispOpr g_DispDevs = NULL;//设备链表表头
static PDispOpr g_DispDefault = NULL;
static DispBuff g_tDispBuff;
static unsigned int line_width;
static unsigned int pixel_width;
//绘制像素
int PutPixel(int x, int y, unsigned int dwColor)
{
char *pen_8 = g_tDispBuff.buff+y*line_width+x*pixel_width;
unsigned short *pen_16;
unsigned int *pen_32;
unsigned int red, green, blue;
pen_16 = (unsigned short *)pen_8;
pen_32 = (unsigned int *)pen_8;
switch (g_tDispBuff.iBpp)
{
case 8:
{
*pen_8 = dwColor;
break;
}
case 16:
{
/* 565 */
red = (dwColor >> 16) & 0xff;
green = (dwColor >> 8) & 0xff;
blue = (dwColor >> 0) & 0xff;
dwColor = ((red >> 3) << 11) | ((green >> 2) << 5) | (blue >> 3);
*pen_16 = dwColor;
break;
}
case 32:
{
*pen_32 = dwColor;
break;
}
default:
{
printf("can't surport %dbpp\n", g_tDispBuff.iBpp);
break;
}
}
return 0;
}
void RegisterDisplay(PDispOpr ptDispOpr)
{
ptDispOpr->ptNext = g_DispDevs;
g_DispDevs = ptDispOpr;
}
//链表中如果存在多个设备，则需要进行设备选择
int SelectDefaultDisplay(char *name)
{
PDispOpr pTmp = g_DispDevs;//从表头开始遍历
while (pTmp)
{
if (strcmp(name, pTmp->name) == 0)//找到了
{
g_DispDefault = pTmp;
return 0;
}
pTmp = pTmp->ptNext;
}
return -1;
}
int InitDefaultDisplay(void)
{
int ret;
ret = g_DispDefault->DeviceInit();
/*在调用前文SelectDefaultDisplay函数后，g_DispDefault即为g_tFramebufferOpr*/
if (ret)
{
printf("DeviceInit err\n");
return -1;
}
ret = g_DispDefault->GetBuffer(&g_tDispBuff);
if (ret)
{
printf("GetBuffer err\n");
return -1;
}
line_width = g_tDispBuff.iXres * g_tDispBuff.iBpp/8;
pixel_width = g_tDispBuff.iBpp/8;
return 0;
}
PDispBuff GetDisplayBuffer(void)
{
return &g_tDispBuff;
}
int FlushDisplayRegion(PRegion ptRegion, PDispBuff ptDispBuff)
{
return g_DispDefault->FlushRegion(ptRegion, ptDispBuff);
}
//文字绘制函数
void DrawFontBitMap(PFontBitMap ptFontBitMap, unsigned int dwColor)
{
int i, j, p, q;
int x = ptFontBitMap->tRegion.iLeftUpX;
int y = ptFontBitMap->tRegion.iLeftUpY;
int x_max = x + ptFontBitMap->tRegion.iWidth;
int y_max = y + ptFontBitMap->tRegion.iHeigh;
int width = ptFontBitMap->tRegion.iWidth;
unsigned char *buffer = ptFontBitMap->pucBuffer;
//printf("x = %d, y = %d\n", x, y);
for ( j = y, q = 0; j < y_max; j++, q++ )
{
for ( i = x, p = 0; i < x_max; i++, p++ )
{
if ( i < 0 || j < 0 ||
i >= g_tDispBuff.iXres || j >= g_tDispBuff.iYres )
continue;
//image[j][i] |= bitmap->buffer[q * bitmap->width + p];
if (buffer[q * width + p])
PutPixel(i, j, dwColor);
}
}
}
// 区域绘制函数
void DrawRegion(PRegion ptRegion, unsigned int dwColor)
{
int x = ptRegion->iLeftUpX;
int y = ptRegion->iLeftUpY;
int width = ptRegion->iWidth;
int heigh = ptRegion->iHeigh;
int i,j;
for (j = y; j < y + heigh; j++)
{
for (i = x; i < x + width; i++)
PutPixel(i, j, dwColor);
}
}
//文本绘制函数
void DrawTextInRegionCentral(char *name, PRegion ptRegion, unsigned int dwColor)
{
int n = strlen(name);
int iFontSize = ptRegion->iWidth / n / 2;
FontBitMap tFontBitMap;
int iOriginX, iOriginY;
int i = 0;
int error;
if (iFontSize > ptRegion->iHeigh)
iFontSize = ptRegion->iHeigh;
iOriginX = (ptRegion->iWidth - n * iFontSize)/2 + ptRegion->iLeftUpX;
iOriginY = (ptRegion->iHeigh - iFontSize)/2 + iFontSize + ptRegion->iLeftUpY;
SetFontSize(iFontSize);
while (name[i])
{
/* get bitmap */
tFontBitMap.iCurOriginX = iOriginX;
tFontBitMap.iCurOriginY = iOriginY;
error = GetFontBitMap(name[i], &tFontBitMap);
if (error)
{
printf("SelectAndInitFont err\n");
return;
}
/* draw on buffer */
DrawFontBitMap(&tFontBitMap, dwColor);
iOriginX = tFontBitMap.iNextOriginX;
iOriginY = tFontBitMap.iNextOriginY;
i++;
}
}
/* display_manager.c */
void DisplayInit(void)
{
extern void FramebufferInit(void); /*对应framebuffer设备lcd输出*/
FramebufferInit();
/*WebTnit()-对应web输出未实现*/
}
3.2 framebuffer.c
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <linux/fb.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <sys/ioctl.h>
#include "disp_manager.h"
static int fd_fb; //设备节点的文件权柄
static struct fb_var_screeninfo var; /* Current var */
static int screen_size;
static unsigned char *fb_base;//LCD的framebuffer地址
static unsigned int line_width;
static unsigned int pixel_width;
static int FbDeviceInit(void) //设备初始化函数
{
fd_fb = open("/dev/fb0", O_RDWR);//打开设备节点
if (fd_fb < 0)
{
printf("can't open /dev/fb0\n");
return -1;
}
if (ioctl(fd_fb, FBIOGET_VSCREENINFO, &var))
{
printf("can't get var\n");
return -1;
}
//var.xres x方向的分辨率
line_width = var.xres * var.bits_per_pixel / 8;
pixel_width = var.bits_per_pixel / 8;
screen_size = var.xres * var.yres * var.bits_per_pixel / 8;
fb_base = (unsigned char *)mmap(NULL , screen_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd_fb, 0);//内存映射
if (fb_base == (unsigned char *)-1)
{
printf("can't mmap\n");
return -1;
}
return 0;
}
static int FbDeviceExit(void) //设备退出函数，释放设备资源
{
munmap(fb_base, screen_size);//取消内存映射
close(fd_fb);
return 0;
}
/* 可以返回LCD的framebuffer, 以后上层APP可以直接操作LCD, 可以不用FbFlushRegion
* 也可以malloc返回一块无关的buffer, 要使用FbFlushRegion
*/
static int FbGetBuffer(PDispBuff ptDispBuff)//获取内存空间
{
ptDispBuff->iXres = var.xres;
ptDispBuff->iYres = var.yres;
ptDispBuff->iBpp = var.bits_per_pixel;
ptDispBuff->buff = (char *)fb_base;
return 0;
}
static int FbFlushRegion(PRegion ptRegion, char *buffer) //刷新函数
{
return 0;
}
// 构建framebuffer设备结构体
static DispOpr g_tFramebufferOpr = {
.name = "fb", //设备的名字是fb
.DeviceInit = FbDeviceInit, //
.DeviceExit = FbDeviceExit, //
.GetBuffer = FbGetBuffer, //获得buf空间中的数据
.FlushRegion = FbFlushRegion, //刷新
};
void FramebufferInit(void)
{
RegisterDisplay(&g_tFramebufferOpr);
}
3.3 Makefile
EXTRA_CFLAGS :=
CFLAGS_file.o :=
obj-y +=disp_manager.o
obj-y +=framebuffer.o四、freetype文件夹
4.1 font_manager.c
#include "font_manager.h"
#include <string.h>
static PFontOpr g_ptFonts = NULL;
static PFontOpr g_ptDefaulFontOpr = NULL;
void RegisterFont(PFontOpr ptFontOpr)
{
ptFontOpr->ptNext = g_ptFonts;
g_ptFonts = ptFontOpr;
}
void FontsRegister(void)
{
extern void FreetypeRegister(void);
FreetypeRegister();
}
int SelectAndInitFont(char *aFontOprName, char *aFontFileName)
{
PFontOpr ptTmp = g_ptFonts;
while (ptTmp)
{
if (strcmp(ptTmp->name, aFontOprName) == 0)
break;
ptTmp = ptTmp->ptNext;
}
if (!ptTmp)
return -1;
g_ptDefaulFontOpr = ptTmp;
return ptTmp->FontInit(aFontFileName);
}
int SetFontSize(int iFontSize)
{
return g_ptDefaulFontOpr->SetFontSize(iFontSize);
}
int GetFontBitMap(unsigned int dwCode, PFontBitMap ptFontBitMap)
{
return g_ptDefaulFontOpr->GetFontBitMap(dwCode, ptFontBitMap);
}
4.2 freetype.c
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <linux/fb.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <wchar.h>
#include <sys/ioctl.h>
#include "font_manager.h"
#include <ft2build.h>//freetype库中的一个头文件
#include FT_FREETYPE_H
#include FT_GLYPH_H
static FT_Face g_tFace;
static int g_iDefaultFontSize = 12;
static int FreeTypeFontInit(char *aFineName)
{
FT_Library library;
int error;
error = FT_Init_FreeType( &library ); /* initialize library */
if (error)
{
printf("FT_Init_FreeType err\n");
return -1;
}
error = FT_New_Face(library, aFineName, 0, &g_tFace ); /* create face object */
if (error)
{
printf("FT_New_Face err\n");
return -1;
}
FT_Set_Pixel_Sizes(g_tFace, g_iDefaultFontSize, 0);
return 0;
}
static int FreeTypeSetFontSize(int iFontSize)
{
FT_Set_Pixel_Sizes(g_tFace, iFontSize, 0);
return 0;
}
//给编码值，得到位图
static int FreeTypeGetFontBitMap(unsigned int dwCode, PFontBitMap ptFontBitMap)
{
int error;
FT_Vector pen;
FT_GlyphSlot slot = g_tFace->glyph;
pen.x = ptFontBitMap->iCurOriginX * 64; /* 单位: 1/64像素 */
pen.y = ptFontBitMap->iCurOriginY * 64; /* 单位: 1/64像素 */
/* 转换：transformation */
FT_Set_Transform(g_tFace, 0, &pen);//FT_Set_Transform是FreeType库中的函数
/* 加载位图: load glyph image into the slot (erase previous one) */
error = FT_Load_Char(g_tFace, dwCode, FT_LOAD_RENDER);
if (error)
{
printf("FT_Load_Char error\n");
return -1;
}
ptFontBitMap->pucBuffer = slot->bitmap.buffer;
ptFontBitMap->tRegion.iLeftUpX = slot->bitmap_left;
ptFontBitMap->tRegion.iLeftUpY = ptFontBitMap->iCurOriginY*2 - slot->bitmap_top;
ptFontBitMap->tRegion.iWidth = slot->bitmap.width;
ptFontBitMap->tRegion.iHeigh = slot->bitmap.rows;
ptFontBitMap->iNextOriginX = ptFontBitMap->iCurOriginX + slot->advance.x / 64;
ptFontBitMap->iNextOriginY = ptFontBitMap->iCurOriginY;
return 0;
}
//描述字库操作及对应具体实现
static FontOpr g_tFreetypeOpr = {
.name = "freetype",
.FontInit = FreeTypeFontInit,
.SetFontSize = FreeTypeSetFontSize,
.GetFontBitMap = FreeTypeGetFontBitMap,
};
void FreetypeRegister(void)
{
RegisterFont(&g_tFreetypeOpr);
}
4.3 front_manager.c
#include "font_manager.h"
#include <string.h>
static PFontOpr g_ptFonts = NULL;
static PFontOpr g_ptDefaulFontOpr = NULL;
void RegisterFont(PFontOpr ptFontOpr)
{
ptFontOpr->ptNext = g_ptFonts;
g_ptFonts = ptFontOpr;
}
void FontsRegister(void)
{
extern void FreetypeRegister(void);
FreetypeRegister();
}
int SelectAndInitFont(char *aFontOprName, char *aFontFileName)
{
PFontOpr ptTmp = g_ptFonts;
while (ptTmp)
{
if (strcmp(ptTmp->name, aFontOprName) == 0)
break;
ptTmp = ptTmp->ptNext;
}
if (!ptTmp)
return -1;
g_ptDefaulFontOpr = ptTmp;
return ptTmp->FontInit(aFontFileName);
}
int SetFontSize(int iFontSize)
{
return g_ptDefaulFontOpr->SetFontSize(iFontSize);
}
int GetFontBitMap(unsigned int dwCode, PFontBitMap ptFontBitMap)
{
return g_ptDefaulFontOpr->GetFontBitMap(dwCode, ptFontBitMap);
}
4.4 Makefile
EXTRA_CFLAGS :=
CFLAGS_file.o :=
obj-y +=freetype.o
obj-y +=font_manager.o五、uniotest文件夹
5.1 ui_test.c
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <linux/fb.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <sys/ioctl.h>
#include <stdlib.h>
#include <disp_manager.h>
#include <font_manager.h>
#include <ui.h> /*包含必要头文件*/
int main(int argc, char **argv)
{
PDispBuff ptBuffer;
int error;
Button tButton;
Region tRegion;
if (argc != 2)
{
printf("Usage: %s <font_size>\n", argv[0]); //打印用法
return -1;
}
DisplayInit(); //显示系统初始化
SelectDefaultDisplay("fb"); //选择lcd设备显示
InitDefaultDisplay(); //初始化lcd设备显示
ptBuffer = GetDisplayBuffer();//获取内存
FontsRegister(); //字体注册
error = SelectAndInitFont("freetype", argv[1]);//字体大小设置
if (error)
{
printf("SelectAndInitFont err\n");
return -1;
}
/*指定按键形状、位置信息*/
tRegion.iLeftUpX = 200;
tRegion.iLeftUpY = 200;
tRegion.iWidth = 600;
tRegion.iHeigh = 200;
InitButton(&tButton,"Alexius_test", &tRegion, NULL, NULL); //按键初始化
tButton.OnDraw(&tButton, ptBuffer); //绘制案件即显示红色按钮与对应按键名
while (1) //按键按下颜色反转
{
tButton.OnPressed(&tButton, ptBuffer, NULL);
sleep(2);
}
return 0;
}
5.2 Makefile
EXTRA_CFLAGS :=
CFLAGS_file.o :=
obj-y +=ui_test.o
六、顶层Makefile及Makefile.build
6.1 Makefile
#指定交叉编译工具链
COSS_COMPLE ?=arm-linux-gnueabihf-
AS = $(COSS_COMPLE)as
LD = $(COSS_COMPLE)ld
CC = $(COSS_COMPLE)gcc
CPP = $(CC) -E
AR = $(CROSS_COMPILE)ar
NM = $(CROSS_COMPILE)nm
STRIP = $(CROSS_COMPILE)strip
OBJCOPY = $(CROSS_COMPILE)objcopy
OBJDUMP = $(CROSS_COMPILE)objdump
# export导出的变量是给子目录下的Makefile使用的
export AS LD CC CPP AR NM
export STRIP OBJCOPY OBJDUMP
# 编译器在编译时的参数设置
CFLAGS := -Wall -O2 -g -DDEBUG
# 添加头文件路径，不添加的话include目录下的头文件编译时找不到
CFLAGS += -I $(shell pwd)/include -I/home/alexius/Downloads/freetype-2.10.2/install/include/freetype2
# 链接器的链接参数设置，链接库
LDFLAGS := -L/home/alexius/Downloads/freetype-2.10.2/install/lib -lfreetype
#-L/home/alexius/Downloads/tslib-1.21/install/lib -lts -lpthread #触摸屏库链接
export CFLAGS LDFLAGS
TOPDIR := $(shell pwd)
export TOPDIR
# 定义将来编译生成的可执行程序的名字
TARGET := ui_test
# 添加项目中所有用到的源文件，有顶层目录下的.c文件，和子文件夹
# 添加顶层目录下的.c文件
#obj-y += main.o
# 添加顶层目录下的子文件夹（注意目录名后面加一个/）
#obj-y += main.o
obj-y += button/
obj-y += uniotest/
obj-y += display/
obj-y += freetype/
# 第一个目标
all : start_recursive_build $(TARGET)
@echo $(TARGET) has been built!
# 处理第一个依赖，**转到 Makefile.build 执行**
start_recursive_build:
make -C ./ -f $(TOPDIR)/Makefile.build
# 处理最终目标，把前期处理得出的 built-in.o 用上
$(TARGET) : built-in.o
$(CC) -o $(TARGET) built-in.o $(LDFLAGS)
# 清理
clean:
rm -f $(shell find -name "*.o")
rm -f $(TARGET)
# 彻底清理
distclean:
rm -f $(shell find -name "*.o")
rm -f $(shell find -name "*.d")
rm -f $(TARGET)
6.2 Makefile.build
# 将__build定义为伪目标
PHONY := __build
__build:
# 这里初值为空，下面引入Makefile文件后会被覆盖
obj-y :=
subdir-y :=
# 包含同级目录的Makefile
include Makefile
# 从obj-y变量中，将"/"结尾的字符串提取出来，也就是包含的子文件夹目录
__subdir-y := $(patsubst %/,%,$(filter %/, $(obj-y)))
subdir-y += $(__subdir-y)
# 将subdir-y变量中的字符串依次赋值给f变量，形成新的$(f)/built-in.o字符串
subdir_objs := $(foreach f,$(subdir-y),$(f)/built-in.o)
# 筛选出obj-y中不以"/"结尾的字符串，也就是普通文件，一般是.o结尾
cur_objs := $(filter-out %/, $(obj-y))
# 为每个.o文件生成.d文件
# 注意.$(f).d是隐藏文件，需要ls -a查看
dep_files := $(foreach f,$(cur_objs),.$(f).d)
dep_files := $(wildcard $(dep_files))
# 如果.d文件不是空，则将.d文件都包含进来
ifneq ($(dep_files),)
include $(dep_files)
endif
PHONY += $(subdir-y)
# __build是Makefile的目标
__build : $(subdir-y) built-in.o
# 依次跳转到子目录中，执行Makefile.build文件
$(subdir-y):
make -C $@ -f $(TOPDIR)/Makefile.build
# 生成当前目录的built-in.o，依赖当前目录的.o文件和子目录下的built-in.o文件
built-in.o : $(cur_objs) $(subdir_objs)
$(LD) -r -o $@ $^
# dep_file变量是用来生成.d文件的
dep_file = .$@.d
# Makefile中的规则，把.c文件编译成.o文件
%.o : %.c
$(CC) $(CFLAGS) -Wp,-MD,$(dep_file) -c -o $@ $<
# 重新定义 .PHONY的依赖
.PHONY : $(PHONY)
七、编译及结果
7.1 编译
7.2 测试结果
将可执行文件ui_test及字库.ttc文件放入开发板下
