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Move file descriptor into bitmap_file struct, renaming and other small tweaks

This commit is contained in:
Curt Spark 2024-07-27 14:23:20 +01:00
parent 626c638ae5
commit 7774f0a1c6
3 changed files with 34 additions and 34 deletions
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24
lib/bmp.c
View File

@ -4,7 +4,7 @@
#include "bmp.h"
uint32_t calc_bitmap_pixel_array_size_bytes(const bitmap *bitmap_in) {
uint32_t calc_bitmap_pixel_array_size_bytes(const bitmap_header *bitmap_in) {
/* We will assume that the bitmap bits per pixel is always a multiple of 8 and sizeof byte is always 8 bits */
uint32_t bytes_unpadded_row = ((bitmap_in->image_width * bitmap_in->bits_per_pixel) / 8);
uint32_t bytes_padded_row = bytes_unpadded_row;
@ -13,12 +13,12 @@ uint32_t calc_bitmap_pixel_array_size_bytes(const bitmap *bitmap_in) {
return bytes_padded_row * bitmap_in->image_height;
};
uint32_t calc_bitmap_file_size_bytes(const bitmap *bitmap_in) {
uint32_t calc_bitmap_file_size_bytes(const bitmap_header *bitmap_in) {
/* We will assume that the bitmap bits per pixel is always a multiple of 8 and sizeof byte is always 8 bits */
return sizeof(bitmap) + calc_bitmap_pixel_array_size_bytes(bitmap_in) - 2 ; /* Take away two to account for compiler padding struct */
return sizeof(bitmap_header) + calc_bitmap_pixel_array_size_bytes(bitmap_in) - 2 ; /* Take away two to account for compiler padding struct */
};
uint32_t calc_bitmap_row_byte_position_start(const bitmap *bitmap_in, const uint32_t row_in) {
uint32_t calc_bitmap_row_byte_position_start(const bitmap_header *bitmap_in, const uint32_t row_in) {
uint32_t bytes_unpadded_row = ((bitmap_in->image_width * bitmap_in->bits_per_pixel) / 8);
uint32_t bytes_padded_row = bytes_unpadded_row;
if (bytes_padded_row % 4)
@ -27,12 +27,11 @@ uint32_t calc_bitmap_row_byte_position_start(const bitmap *bitmap_in, const uint
};
uint32_t calc_bitmap_header_size_bytes() {
return sizeof(bitmap) - 2 ; /* Take away two to account for compiler padding struct */
return sizeof(bitmap_header) - 2 ; /* Take away two to account for compiler padding struct */
};
/* Change name to init_bitmap_header */
bitmap init_bitmap(const int32_t image_width_in, const int32_t image_height_in) {
bitmap new_bitmap;
bitmap_header init_bitmap_header(const int32_t image_width_in, const int32_t image_height_in) {
bitmap_header new_bitmap;
/* Bitmap Info Header */
new_bitmap.info_header_size_bytes = 40;
new_bitmap.image_width = image_width_in;
@ -58,8 +57,7 @@ bitmap init_bitmap(const int32_t image_width_in, const int32_t image_height_in)
return new_bitmap;
};
/* Change the name to init_bitmap_file */
bitmap_file write_to_bitmap(const bitmap *bitmap_in, const char *filename) {
bitmap_file init_bitmap_file(const bitmap_header *bitmap_in, const char *filename) {
bitmap_file new_bitmap_file;
int8_t write_status;
uint32_t current_byte;
@ -79,19 +77,19 @@ bitmap_file write_to_bitmap(const bitmap *bitmap_in, const char *filename) {
/* TODO Need an error return type */
return new_bitmap_file;
}
close(fd);
new_bitmap_file.filename = filename;
new_bitmap_file.bitmap_metadata = bitmap_in;
new_bitmap_file.fd = fd;
return new_bitmap_file;
};
int write_bitmap_pixel(int8_t fd, const bitmap_file *bitmap_file_in, const bitmap_pixel_color *bitmap_pixel_in, const int32_t x_in, const int32_t y_in) {
int write_bitmap_pixel(const bitmap_file *bitmap_file_in, const bitmap_pixel_color *bitmap_pixel_in, const int32_t x_in, const int32_t y_in) {
int8_t write_status;
int32_t byte_position_start = calc_bitmap_row_byte_position_start(bitmap_file_in->bitmap_metadata, y_in) + ((x_in - 1) * 3);
uint8_t *bitmap_pixel_in_byte_ptr = (uint8_t *)bitmap_pixel_in;
write_status = pwrite(fd, bitmap_pixel_in_byte_ptr, 3, bitmap_file_in->bitmap_metadata->image_data_start_offset + byte_position_start);
write_status = pwrite(bitmap_file_in->fd, bitmap_pixel_in_byte_ptr, 3, bitmap_file_in->bitmap_metadata->image_data_start_offset + byte_position_start);
return 0;
};

29
lib/bmp.h
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@ -3,8 +3,7 @@
#include <stdint.h>
/* Change struct name to bitmap header */
typedef struct bitmap {
typedef struct bitmap_header {
/* File Header */
/* The header field used to identify the BMP and DIB file is 0x42 0x4D in hexadecimal, same as BM in ASCII. The following entries are possible:
@ -39,11 +38,12 @@ typedef struct bitmap {
int32_t vertical_resolution_pixels_per_metre;
uint32_t colors_in_palette;
uint32_t important_colors;
} bitmap;
} bitmap_header;
typedef struct bitmap_file {
char *filename;
bitmap *bitmap_metadata;
bitmap_header *bitmap_metadata;
uint8_t fd;
} bitmap_file;
typedef struct bitmap_pixel_color {
@ -52,16 +52,21 @@ typedef struct bitmap_pixel_color {
uint8_t red;
} bitmap_pixel_color;
/* Change struct name to bitmap header */
bitmap init_bitmap(const int32_t image_width_in, const int32_t image_height_in);
/* Change the name to init_bitmap_file */
bitmap_file write_to_bitmap(const bitmap *bitmap_in, const char *filename);
/* Initialises and writes a new bitmap file with correctly set headers and a blank pixel array. Returns a bitmap_header struct containing all bitmap header info. */
bitmap_header init_bitmap_header(const int32_t image_width_in, const int32_t image_height_in);
/* Initialises and returns a new bitmap_file struct which contains a str pointer to the filename, the bitmap header metadata and an open file descriptor */
bitmap_file init_bitmap_file(const bitmap_header *bitmap_in, const char *filename);
uint32_t calc_bitmap_row_byte_position_start(const bitmap *bitmap_in, const uint32_t row_in);
uint32_t calc_bitmap_file_size_bytes(const bitmap *bitmap_in);
uint32_t calc_bitmap_pixel_array_size_bytes(const bitmap *bitmap_in);
/* Calculate byte position a particular row starts */
uint32_t calc_bitmap_row_byte_position_start(const bitmap_header *bitmap_in, const uint32_t row_in);
/* Calculate full size of the bitmap */
uint32_t calc_bitmap_file_size_bytes(const bitmap_header *bitmap_in);
/* Calculate size of bitmap pixel array only */
uint32_t calc_bitmap_pixel_array_size_bytes(const bitmap_header *bitmap_in);
/* Calculate size of bitmap header only */
uint32_t calc_bitmap_header_size_bytes();
int write_bitmap_pixel(const int8_t fd, const bitmap_file *bitmap_file_in, const bitmap_pixel_color *bitmap_pixel_in, const int32_t x_in, const int32_t y_in);
/* Write bitmap pixel at particular coordinate */
int write_bitmap_pixel(const bitmap_file *bitmap_file_in, const bitmap_pixel_color *bitmap_pixel_in, const int32_t x_in, const int32_t y_in);
#endif

15
main.c
View File

@ -2,6 +2,7 @@
#include <stdint.h>
#include <fcntl.h>
#include <unistd.h>
#include <wctype.h>
#include "lib/temperature.h"
#include "lib/array.h"
#include "lib/base10.h"
@ -15,8 +16,6 @@ void swap_int(int *pX, int *pY) {
*pY = temp;
}
int main() {
/* TODO: Move all of this stuff into its own projects */
@ -41,22 +40,20 @@ int main() {
ss_alloc_free(reserved_memory);
printf("Memory : %d/%d", ALLOC_SIZE, (int)ss_alloc_get_used_bytes());*/
const bitmap test = init_bitmap(255, 255);
/* TODO: Include fd as part of write to bitmap */
const bitmap_file test_file = write_to_bitmap(&test, "test.bmp");
const bitmap_header test = init_bitmap_header(1920, 1080);
const bitmap_file test_file = init_bitmap_file(&test, "test.bmp");
bitmap_pixel_color target_pixel;
int32_t width;
int32_t height;
int8_t fd = open(test_file.filename, O_WRONLY | O_CREAT, 0666);
for (height = 1; height <= test_file.bitmap_metadata->image_height; ++height) {
for (width = 1; width <= test_file.bitmap_metadata->image_width; ++width) {
target_pixel.red = ((float)width / (float)test_file.bitmap_metadata->image_width) * 255;
target_pixel.green = ((float)height / (float)test_file.bitmap_metadata->image_height) * 255;
target_pixel.blue = 255;
write_bitmap_pixel(fd, &test_file, &target_pixel, width, height);
target_pixel.blue = 100;
write_bitmap_pixel(&test_file, &target_pixel, width, height);
}
}
close(fd);
close(test_file.fd);
}