P3221 Го Цзыхань

P3221 Го Цзыхань 291300

solution/include/bmp.h

 #include <stdint.h>
 #include <stdio.h>
 
-// bmp
-#pragma pack(push, 1)//struct对齐
-struct bmp_header {
-    uint16_t bfType;//文件类型，BMP格式的文件这两个字节是0x4D42，10进制就是19778，字符显示就是‘BM’
-    uint32_t bfileSize;//文件大小(包含这14字节)
-    uint32_t bfReserved;//保留字，不考虑 包含bfReserved1和bfReserved2各两个字节，必须设置为0
-    uint32_t bOffBits;//4字节的偏移，表示从文件头到位图数据的偏移，
-    uint32_t biSize;//指定此结构体的长度，为40
-    uint32_t biWidth;//位图宽
-    uint32_t biHeight;//位图高
-    uint16_t biPlanes;//平面数，为1
-    uint16_t biBitCount;//采用颜色位数，可以是1，2，4，8，16，24，新的可以是32
-    uint32_t biCompression; //压缩方式，可以是0，1，2，最常用的就是0（BI_RGB），表示不压缩
-    uint32_t biSizeImage;//实际位图数据的大小
-    uint32_t biXPelsPerMeter;//X方向分辨率
-    uint32_t biYPelsPerMeter;//Y方向分辨率
-    uint32_t biClrUsed;//使用的颜色数，如果为0说明使用所有，表示默认值(2^颜色位数)
-    uint32_t biClrImportant;//重要颜色数，如果为0，则表示所有颜色都是重要的
-};
-#pragma pack(pop)
-
 // image
-struct image {
-    uint64_t width, height;
-    struct pixel *data;
-};
-
-struct pixel {
-    uint8_t r;
-    uint8_t g;
-    uint8_t b;
-}__attribute__((__packed__));
+struct image;
 
+struct pixel;
 
-enum read_status {
+enum read_status
+{
     READ_OK = 0,
     READ_INVALID_SIGNATURE,
     READ_INVALID_BITS,
     READ_ERROR
 };
 
-enum write_status {
+enum write_status
+{
     WRITE_OK = 0,
     WRITE_ERROR
 };
 
 enum write_status to_bmp(FILE *out, struct image const *img);
 
+void free_image(struct image *img);
+
+struct image *new_image(void);
+
+struct image *constructor_image(uint64_t width, uint64_t height);
+struct pixel *get_pixel(const struct image *img, size_t col, size_t row);
+void set_pixel(const struct image *img, struct pixel* pixel, size_t col, size_t row);
+uint64_t get_width(struct image const *source);
+uint64_t get_height(struct image const *source);
+
 #endif // BMP_H

solution/include/rotate.h

 
 #include "bmp.h"
 
-struct image rotate(struct image const source);
+struct image* rotate(struct image const* source);
 
 #endif // ROTATE_H

solution/src/bmp.c

 #include "../include/bmp.h"
 
+// bmp
+#pragma pack(push, 1) // struct对齐
+struct bmp_header
+{
+    uint16_t bfType;          //文件类型，BMP格式的文件这两个字节是0x4D42，10进制就是19778，字符显示就是‘BM’
+    uint32_t bfileSize;       //文件大小(包含这14字节)
+    uint32_t bfReserved;      //保留字，不考虑 包含bfReserved1和bfReserved2各两个字节，必须设置为0
+    uint32_t bOffBits;        // 4字节的偏移，表示从文件头到位图数据的偏移，
+    uint32_t biSize;          //指定此结构体的长度，为40
+    uint32_t biWidth;         //位图宽
+    uint32_t biHeight;        //位图高
+    uint16_t biPlanes;        //平面数，为1
+    uint16_t biBitCount;      //采用颜色位数，可以是1，2，4，8，16，24，新的可以是32
+    uint32_t biCompression;   //压缩方式，可以是0，1，2，最常用的就是0（BI_RGB），表示不压缩
+    uint32_t biSizeImage;     //实际位图数据的大小
+    uint32_t biXPelsPerMeter; // X方向分辨率
+    uint32_t biYPelsPerMeter; // Y方向分辨率
+    uint32_t biClrUsed;       //使用的颜色数，如果为0说明使用所有，表示默认值(2^颜色位数)
+    uint32_t biClrImportant;  //重要颜色数，如果为0，则表示所有颜色都是重要的
+};
+#pragma pack(pop)
+
+struct image
+{
+    uint64_t width, height;
+    struct pixel *data;
+};
+
+struct pixel
+{
+    uint8_t r;
+    uint8_t g;
+    uint8_t b;
+} __attribute__((__packed__));
+
+struct image *new_image(void)
+{
+    struct image *image = NULL;
+    image = (struct image *)malloc(sizeof(struct image));
+    return image;
+}
+
+struct image *constructor_image(uint64_t width, uint64_t height)
+{
+    struct image *image = NULL;
+    image = (struct image *)malloc(sizeof(struct image));
+    image->height = height;
+    image->width = width;
+    image->data = malloc(sizeof(struct pixel) * width * height);
+    return image;
+}
+
+struct pixel *get_pixel(const struct image *img, size_t col, size_t row)
+{
+    return &(img->data[row * img->width + col]);
+}
+void set_pixel(const struct image *img, struct pixel *pixel, size_t col, size_t row)
+{
+    img->data[row * img->width + col] = *pixel;
+}
+
+uint64_t get_width(struct image const *source)
+{
+    return source->width;
+}
+
+uint64_t get_height(struct image const *source)
+{
+    return source->height;
+}
+
+void free_image(struct image *img)
+{
+    free(img->data);
+    free(img);
+}
+
 static const uint16_t NUM_bf_Type = 0x4D42;
 static const uint16_t NUM_bi_Bit_Count = 24;
 static const uint32_t NUM_bi_Size = 40;
 static const uint32_t DOUBLE_SIZE = 4;
 
-enum read_status from_bmp(FILE *in, struct image *img) {
-    if (!in || !img) { return READ_ERROR; }
+bool header_reader(FILE *in, struct bmp_header *header);
+bool fread_check(FILE *in, struct image const *img, uint64_t i);
+bool fseek_check(FILE *in_out, size_t padding);
+bool fwrite_check(FILE *out, void *data, size_t size, uint64_t value);
 
-    struct bmp_header header;
-    fread(&header, sizeof(struct bmp_header), 1, in);
-    if (header.bfType > NUM_bf_Type || header.bfType <= 0) { return READ_INVALID_SIGNATURE; }
-    if (header.biBitCount != NUM_bi_Bit_Count) { return READ_INVALID_BITS; }
-    if (header.biSize != NUM_bi_Size) { return READ_INVALID_HEADER; }
-    img->height = header.biHeight;
-    img->width = header.biWidth;
-    img->data = malloc(sizeof(struct pixel) * img->width * img->height);
+enum read_status check_bmp_correctness(struct bmp_header *header);
+void constructor_bmp(struct image *img, struct bmp_header *header);
+size_t calculate_padding(const uint32_t DS, const uint64_t width, const uint16_t NbBC);
+struct bmp_header init_header(struct image const *img);
 
-    size_t padding = DOUBLE_SIZE - ((img->width * NUM_bi_Bit_Count) >> 3) & 3;//计算偏移量
-    for (int i = 0; i < img->height; i++) {
-        fread((char *) img->data + i * img->width * 3, 3, img->width, in);//读取“有内容”的字节
-        fseek(in, padding, SEEK_CUR);//跳过补零的字节
+enum read_status from_bmp(FILE *in, struct image *img)
+{
+    if (!in || !img)
+    {
+        return READ_ERROR;
+    }
+
+    struct bmp_header header;
+    if (header_reader(in, &header))
+        return READ_ERROR;
+    enum read_status read_state = check_bmp_correctness(&header);
+    if (read_state != READ_OK)
+        return read_state;
+    constructor_bmp(img, &header);
+    const size_t padding = calculate_padding(DOUBLE_SIZE, img->width, NUM_bi_Bit_Count); //计算偏移量
+    for (uint64_t i = 0; i < img->height; i++)
+    {
+        if (fread_check(in, img, i) || fseek_check(in, padding))
+        {
+            img->height = img->width = -1;
+            free(img->data);
+            return READ_ERROR;
+        }
     }
 
     return READ_OK;
 }
 
-enum write_status to_bmp(FILE *out, struct image const *img) {
-    if (!out || !img) { return WRITE_ERROR; }
-
-    size_t padding = DOUBLE_SIZE - ((img->width * NUM_bi_Bit_Count) >> 3) & 3;//计算偏移量
-    struct bmp_header header = {
-            .bfType=NUM_bf_Type,
-            .biSizeImage=((img->width * NUM_bi_Bit_Count + 31) >> 5)
-                    << 2 * img->height, //biSizeImage = bytesPerLine * imageSize
-            .bOffBits=sizeof(struct bmp_header),
-            .biSize=NUM_bi_Size,
-            .biWidth=img->width,
-            .biHeight=img->height,
-            .biPlanes=1,
-            .biBitCount=NUM_bi_Bit_Count,
-    };
-    header.bfileSize = header.biSizeImage + sizeof(struct bmp_header);
-    fwrite(&header, sizeof(struct bmp_header), 1, out);
-
-    for (int i = 0; i < img->height; i++) {
-        fwrite((char *) img->data + i * img->width * 3, 3, img->width, out);//写入有内容的字节
-        fseek(out, padding, SEEK_CUR);//跳过补零的字节
+enum write_status to_bmp(FILE *out, struct image const *img)
+{
+    if (!out || !img)
+    {
+        return WRITE_ERROR;
+    }
+
+    const size_t padding = calculate_padding(DOUBLE_SIZE, img->width, NUM_bi_Bit_Count); //计算偏移量
+    struct bmp_header header = init_header(img);
+
+    if (fwrite_check(out, &header, sizeof(struct bmp_header), 1))
+        return WRITE_ERROR;
+
+    for (uint64_t i = 0; i < img->height; i++)
+    {
+        if (fwrite_check(out, img->data + i * img->width, sizeof(struct pixel), img->width) || fseek_check(out, padding))
+            return WRITE_ERROR;
     }
 
     return WRITE_OK;
 }
+
+enum read_status check_bmp_correctness(struct bmp_header *header)
+{
+    if (header->bfType > NUM_bf_Type || header->bfType <= 0)
+    {
+        return READ_INVALID_SIGNATURE;
+    }
+    if (header->biBitCount != NUM_bi_Bit_Count)
+    {
+        return READ_INVALID_BITS;
+    }
+    if (header->biSize != NUM_bi_Size)
+    {
+        return READ_INVALID_HEADER;
+    }
+    return READ_OK;
+}
+
+void constructor_bmp(struct image *img, struct bmp_header *header)
+{
+    img->height = header->biHeight;
+    img->width = header->biWidth;
+    img->data = malloc(sizeof(struct pixel) * img->width * img->height);
+}
+
+size_t calculate_padding(const uint32_t DS, const uint64_t width, const uint16_t NbBC)
+{
+    return DS - ((width * NbBC) >> 3) & 3;
+}
+
+uint32_t biSizeImage_calc(struct image const *img)
+{
+    return ((img->width * NUM_bi_Bit_Count + 31) >> 5)
+           << 2 * img->height;
+}
+
+struct bmp_header init_header(struct image const *img)
+{
+    return (struct bmp_header){
+        .bfType = NUM_bf_Type,
+        .biSizeImage = biSizeImage_calc(img), // biSizeImage = bytesPerLine * imageSize
+        .bOffBits = sizeof(struct bmp_header),
+        .biSize = NUM_bi_Size,
+        .biWidth = img->width,
+        .biHeight = img->height,
+        .biPlanes = 1,
+        .biBitCount = NUM_bi_Bit_Count,
+        .bfileSize = biSizeImage_calc(img) + sizeof(struct bmp_header)};
+}
+
+bool header_reader(FILE *in, struct bmp_header *header)
+{
+    return fread(header, sizeof(struct bmp_header), 1, in) == 0;
+}
+
+bool fread_check(FILE *in, struct image const *img, uint64_t i)
+{
+    return fread((char *)img->data + i * img->width * sizeof(struct pixel), sizeof(struct pixel), img->width, in) != img->width;
+}
+
+bool fseek_check(FILE *in_out, size_t padding)
+{
+    return fseek(in_out, padding, SEEK_CUR) != 0;
+}
+
+bool fwrite_check(FILE *out, void *data, size_t size, uint64_t value)
+{
+    return fwrite(data, size, value, out) != value;
+}