fixed commented problems

solution/include/image_io.h

@@ -4,7 +4,8 @@
 #include <stdio.h>
 
 enum read_status {
-    READ_OK = 0,
+    READ_OK,
+    READ_IMAGE_NULL,
     READ_FILE_CLOSED,
     READ_EOF,
     READ_INVALID_HEADER
@@ -13,7 +14,9 @@ enum read_status {
 enum read_status read_image(const char* path, struct image* img);
 
 enum write_status {
-    WRITE_OK = 0,
+    WRITE_OK,
+    WRITE_IMAGE_NULL = 0xF, // чтобы коды ошибок отличались для чтения/записи
+    WRITE_EOF,
     WRITE_FILE_CLOSED
 };
 

solution/src/bmp_format.c

@@ -13,6 +13,25 @@
 #define DWORD_SIZE 4
 #define BI_BIT_COUNT 24
 
+struct __attribute__((packed)) bmp_header
+{
+    uint16_t bfType;
+    uint32_t  bfileSize;
+    uint32_t bfReserved;
+    uint32_t bOffBits;
+    uint32_t biSize;
+    uint32_t biWidth;
+    uint32_t  biHeight;
+    uint16_t  biPlanes;
+    uint16_t biBitCount;
+    uint32_t biCompression;
+    uint32_t biSizeImage;
+    uint32_t biXPelsPerMeter;
+    uint32_t biYPelsPerMeter;
+    uint32_t biClrUsed;
+    uint32_t  biClrImportant;
+};
+
 size_t get_padding(struct image const* img) {
 	return 4 - (img->width * sizeof(struct pixel)) % 4;
 }
@@ -49,6 +68,9 @@ struct bmp_header prepare_bmp_header(struct image const* img) {
     return header;
 }
 
+// Проверка на валидность файла и указателя на картинку
+// принципиально вынесена в другой уровень абстракции
+// См. image_io.c
 enum read_status from_bmp( FILE* in, struct image* img ) {
     struct bmp_header header;
     if (!fread(&header, sizeof(header), 1, in)) return READ_INVALID_HEADER;
@@ -56,7 +78,7 @@ enum read_status from_bmp( FILE* in, struct image* img ) {
     img->height = header.biHeight;
     img->data = (struct pixel*) malloc(body_size(img));
 	for (size_t i = 0; i < img->height; i++) {
-		if (fread(&img->data[i * img->width], sizeof(struct pixel), img->width, in) < img->width) return READ_EOF;
+		if (fread(&img->data[i * img->width], sizeof(struct pixel), img->width, in) != img->width) return READ_EOF;
 		fseek(in, get_padding(img), SEEK_CUR);
 	}
     return READ_OK;
@@ -66,8 +88,8 @@ enum write_status to_bmp( FILE* out, struct image const* img ) {
     struct bmp_header header = prepare_bmp_header(img);
     fwrite(&header, sizeof(struct bmp_header), 1, out);
     for (size_t i = 0; i < img->height; i++) {
-		fwrite(&img->data[i * img->width], sizeof(struct pixel), img->width, out);
-		fwrite(&img->data, 1, get_padding(img), out);
+		if (fwrite(&img->data[i * img->width], sizeof(struct pixel), img->width, out) != img->width) return WRITE_EOF;
+		if (fwrite(&img->data, 1, get_padding(img), out) != get_padding(img)) return WRITE_EOF;
 	}
     return WRITE_OK;
 }

solution/src/image_io.c

@@ -3,22 +3,18 @@
 
 enum read_status read_image(const char* path, struct image* img) {
     FILE* fin = fopen(path, "r");
-    if (fin) {
-        enum read_status read_status = from_bmp(fin, img);
-        fclose(fin);
-        return read_status;
-    } else {
-        return READ_FILE_CLOSED;
-    }
+    if (!img) return READ_IMAGE_NULL;
+    if (!fin) return READ_FILE_CLOSED;
+    enum read_status read_status = from_bmp(fin, img);
+    fclose(fin);
+    return read_status;
 }
 
 enum write_status write_image(const char* path, struct image* img) {
     FILE* fout = fopen(path, "w");
-    if (fout) {
-        enum write_status write_status = to_bmp(fout, img);
-        fclose(fout);
-        return write_status;
-    } else {
-        return WRITE_FILE_CLOSED;
-    }
+    if (!img) return WRITE_IMAGE_NULL;
+    if (!fout) return WRITE_FILE_CLOSED;
+    enum write_status write_status = to_bmp(fout, img);
+    fclose(fout);
+    return write_status;
 }

solution/src/main.c

@@ -4,7 +4,7 @@
 #include "rotate.h"
 
 int main(int argc, char** argv) {
-    if (argc < 3) {
+    if (argc != 3) {
         printf("This program takes two arguments!");
         return -1;
     }