解释:row = ((row & 0x00FF) << 8) | ((row & 0xFF00) >> 8);
时间: 2024-05-22 17:16:22 浏览: 109
+ 1) % len(grid)) if the current row is not the last row in the grid, otherwise it becomes the first row.
This code is using the modulo operator (%) to check if the current row is the last row in the grid. If it is not the last row, then it adds 1 to the row number and assigns the result to row. If it is the last row, then it assigns 0 (the first row) to row.
This code is useful when iterating through a 2-dimensional grid in a loop and you want to cycle through the rows. It ensures that the loop will continue from the first row after reaching the last row.
相关问题
编程实现:多线程操作GEC210开发板的LCD,实现BMP图片显示的“百叶窗”效果。提示:LCD映射为一片内存,多条线程分别同时操作该内存的不同区域。
这个问题需要结合具体的编程语言和开发板来实现。下面是一个C语言版本的参考代码,假设开发板的LCD映射内存为0x80000000,图片为320x240的BMP格式,要实现10个“百叶窗”效果。
```c
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define LCD_WIDTH 320
#define LCD_HEIGHT 240
#define LCD_MEM_ADDR 0x80000000
#define WINDOW_NUM 10
typedef struct {
int start_row;
int end_row;
} window_t;
void* thread_func(void* arg) {
window_t* win = (window_t*)arg;
int row_bytes = LCD_WIDTH * 3;
int start_addr = LCD_MEM_ADDR + win->start_row * row_bytes;
int end_addr = LCD_MEM_ADDR + win->end_row * row_bytes;
int i, j;
while (1) {
for (i = start_addr; i < end_addr; i += row_bytes) {
for (j = i; j < i + row_bytes; j += 3) {
*(volatile unsigned int*)j = 0xFF0000;
*(volatile unsigned int*)(j + 1) = 0x00FF00;
*(volatile unsigned int*)(j + 2) = 0x0000FF;
}
}
usleep(10000);
}
return NULL;
}
int main() {
pthread_t threads[WINDOW_NUM];
window_t windows[WINDOW_NUM];
int i, ret;
for (i = 0; i < WINDOW_NUM; i++) {
windows[i].start_row = i * (LCD_HEIGHT / WINDOW_NUM);
windows[i].end_row = (i + 1) * (LCD_HEIGHT / WINDOW_NUM);
ret = pthread_create(&threads[i], NULL, thread_func, &windows[i]);
if (ret != 0) {
perror("pthread_create");
exit(EXIT_FAILURE);
}
}
for (i = 0; i < WINDOW_NUM; i++) {
pthread_join(threads[i], NULL);
}
return 0;
}
```
这个程序使用了pthread库来创建多个线程,每个线程都负责操作LCD映射内存的一部分,实现“百叶窗”效果。具体实现过程为:每个线程在循环中先将自己负责的区域填充为同样的颜色,然后等待一段时间再重复这个过程。由于多个线程同时操作LCD映射内存的不同区域,因此可以实现“百叶窗”效果。
请你书写代码,实现:STM32在100100处画120120正方形,背景为红色,方块为蓝色
好的,以下是代码实现:
```
#include "stm32f10x.h"
#include "stm32f10x_gpio.h"
#include "stm32f10x_rcc.h"
#include "stm32f10x_spi.h"
#include "stm32f10x_tim.h"
void drawSquare(int x, int y, int size, int bgColor, int sqColor);
void setup()
{
// 开启GPIO和TIM时钟
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO | RCC_APB2Periph_TIM1, ENABLE);
// 配置PA8为TIM1通道1的输出PWM
GPIO_InitTypeDef gpioInit;
gpioInit.GPIO_Pin = GPIO_Pin_8;
gpioInit.GPIO_Mode = GPIO_Mode_AF_PP;
gpioInit.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &gpioInit);
// 配置TIM1为PWM模式
TIM_TimeBaseInitTypeDef timBaseInit;
timBaseInit.TIM_Period = 7999;
timBaseInit.TIM_Prescaler = 11;
timBaseInit.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM1, &timBaseInit);
TIM_OCInitTypeDef timOcInit;
timOcInit.TIM_OCMode = TIM_OCMode_PWM1;
timOcInit.TIM_OutputState = TIM_OutputState_Enable;
timOcInit.TIM_Pulse = 0;
TIM_OC1Init(TIM1, &timOcInit);
TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);
// 启动TIM1
TIM_Cmd(TIM1, ENABLE);
}
int main(void)
{
// 初始化
setup();
// 画正方形,默认位置和大小为(100, 100, 120)
drawSquare(100, 100, 120, 0xff0000, 0x0000ff);
// 死循环
while (1);
return 0;
}
void drawSquare(int x, int y, int size, int bgColor, int sqColor)
{
uint16_t init_x = x;
uint16_t init_y = y;
// 配置SPI接口
RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO | RCC_APB2Periph_GPIOA | RCC_APB2Periph_SPI1, ENABLE);
GPIO_InitTypeDef gpio_init;
gpio_init.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_7 | GPIO_Pin_4;
gpio_init.GPIO_Speed = GPIO_Speed_10MHz;
gpio_init.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOA, &gpio_init);
spi_init();
// 画背景色(红色)
set_color(bgColor);
spi_set_pos(init_x, init_y, init_x+size-1, init_y+size-1);
for (int i = 0; i < size*size; i++)
{
spi_write_data(bgColor >> 8);
spi_write_data(bgColor & 0xff);
}
// 画正方形(蓝色)
set_color(sqColor);
spi_set_pos(init_x+1, init_y+1, init_x+size-2, init_y+size-2);
for (int i = 0; i < (size-2)*(size-2); i++)
{
spi_write_data(sqColor >> 8);
spi_write_data(sqColor & 0xff);
}
}
void spi_init() {
SPI_InitTypeDef spi_init;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);
spi_init.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
spi_init.SPI_Mode = SPI_Mode_Master;
spi_init.SPI_DataSize = SPI_DataSize_16b;
spi_init.SPI_CPOL = SPI_CPOL_High;
spi_init.SPI_CPHA = SPI_CPHA_2Edge;
spi_init.SPI_NSS = SPI_NSS_Soft;
spi_init.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256;
spi_init.SPI_FirstBit = SPI_FirstBit_MSB;
spi_init.SPI_CRCPolynomial = 7;
SPI_Init(SPI1, &spi_init);
SPI_Cmd(SPI1, ENABLE);
}
void set_color(uint16_t color) {
TIM1->CCR1 = (color >> 8) << 2;
}
void spi_send_cmd(uint8_t cmd){
GPIO_ResetBits(GPIOA, GPIO_Pin_4);
SPI_I2S_SendData(SPI1, cmd);
while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) != RESET);
}
void spi_send_data(uint8_t data){
GPIO_SetBits(GPIOA, GPIO_Pin_4);
SPI_I2S_SendData(SPI1, data);
while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) != RESET);
}
void spi_set_pos(uint16_t x_start, uint16_t y_start, uint16_t x_end, uint16_t y_end){
spi_send_cmd(0x2A);//Column Command Set
spi_send_data(x_start >> 8);
spi_send_data(x_start & 0xff);
spi_send_data(x_end >> 8);
spi_send_data(x_end & 0xff);
spi_send_cmd(0x2B);//Row Command Set
spi_send_data(y_start >> 8);
spi_send_data(y_start & 0xff);
spi_send_data(y_end >> 8);
spi_send_data(y_end & 0xff);
spi_send_cmd(0x2C);//Memory Write
}
void spi_write_data(uint16_t data) {
spi_send_data(data >> 8);
spi_send_data(data & 0xff);
}
```
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