如何解决如何初始化二维结构数组的值?
我正在编写一个带有二维结构数组的 ppm 文件,这些结构充当 rgb 值。该文件写入,但是当我尝试通过我的 drawRect 和 drawCircle 函数传递包含我想要的颜色值的结构时,图像没有按照我想要的尺寸绘制。像素值也没有正确写入数组。我有单独的函数来绘制矩形和圆形,createImg 绘制整个图像。
struct Color {
unsigned char red;
unsigned char green;
unsigned char blue;
};
int main() {
static Color image[LENGTH][WIDTH] = {};
createImg(image);
writeImg(image,300,"torinCostales.ppm");
}
void createImg(Color image[][WIDTH]) {
//variables for red green and blue
Color red = { 255,0 };
Color green = { 0,255,0 };
Color blue = { 0,255 };
//dimensions and color value for the 4 different shapes
drawRect(image,20,15,75,150,blue);
drawRect(image,100,50,red);
drawCircle(image,200,green);
drawCircle(image,red);
//-------------------------------------------------------------------
//draws circle with given dimensions and sets array values to colorLevel
void drawCircle(Color image[][WIDTH],int centerX,int centerY,int radius,Color colorLevel) {
for (int x = centerX - radius; x <= centerX + radius; x++)
for (int y = centerY - radius; y <= centerY + radius; y++)
if ((x - centerX) * (x - centerX) + (y - centerY) * (y - centerY) <= radius * radius)
image[x][y] = colorLevel;
}
//--------------------------------------------------------------------
//draws the rectangle with given dimensions and colorLevel
void drawRect(Color image[][WIDTH],int rectTop,int rectLeft,int rectHeight,int rectWidth,Color colorLevel) {
for (int col = rectLeft; col < rectWidth + rectLeft; coL++)
for (int rows = rectTop; rows < rectHeight + rectTop; rows++)
image[col][rows] = colorLevel;
}
//writes the file
void writeImg(const Color image[][WIDTH],int height,const string fileName) {
std::ofstream imgFile;
imgFile.open("torinCostales.ppm");
//header
imgFile << "P3";
imgFile << "\n" << WIDTH << ' ' << LENGTH;
imgFile << "\n" << "255" << "\n";
//writes pixel values
for (int row = 0; row < LENGTH; row++) {
for (int col = 0; col < WIDTH; coL++)
imgFile << static_cast<int>(image[row][col].red << image[row][col].green << image[row][col].blue) << ' ';
imgFile << '\n';
}
imgFile.close();
}
解决方法
看起来这一行是错误的:
imgFile << static_cast<int>(image[row][col].red << image[row][col].green << image[row][col].blue) << ' ';
不是将每种颜色投射到 int
,而是将 red
的值按 green
指定的位数SHIFT,然后按 {{1 }}。
你想要这个:
blue
版权声明:本文内容由互联网用户自发贡献,该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 dio@foxmail.com 举报,一经查实,本站将立刻删除。