claycow.com
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Makefile
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Makefile
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README.md
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README.md
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# Portable Pixel Map Library
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I originally made this because I was watching a [video](https://youtu.be/dCqIKDo_Hkc?si=F_H5uxOoQ06eCzkw) from [Jacob Sorber](https://www.youtube.com/@JacobSorber) that show PPM as a very easy to use image format for beginners. I've been interested in making more things in C and I thought this would be a fairly easy exercise at creating my own PPM library.
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ppm.c
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ppm.c
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#include "ppm.h"
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#include <inttypes.h>
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#include <math.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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ppm_image *ppm_create(uint64_t height, uint64_t width) {
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return ppm_create_with_background_color(height, width, PPM_BLACK);
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}
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ppm_image *ppm_create_with_background_color(uint64_t height, uint64_t width,
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ppm_rgb background_color) {
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ppm_image *image = (ppm_image *)malloc(sizeof(ppm_image));
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image->height = height;
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image->width = width;
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ppm_rgb *data = (ppm_rgb *)malloc(sizeof(ppm_rgb) * width * height);
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for (uint64_t y = 0; y < height; y++) {
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for (uint64_t x = 0; x < width; x++) {
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uint64_t position = (y * width) + x;
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data[position] = background_color;
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}
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}
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image->data = data;
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return image;
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}
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int ppm_destroy(ppm_image *image) {
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free(image->data);
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free(image);
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return EXIT_SUCCESS;
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}
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int ppm_is_in_bounds(ppm_image *image, uint64_t x, uint64_t y) {
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if (x <= 0)
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return EXIT_FAILURE;
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if (x > image->width)
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return EXIT_FAILURE;
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if (y <= 0)
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return EXIT_FAILURE;
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if (y > image->height)
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return EXIT_FAILURE;
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return EXIT_SUCCESS;
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}
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int ppm_to_ppm3_file(ppm_image *image, const char *file_path) {
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FILE *file = fopen(file_path, "w");
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fprintf(file, "P3\n");
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fprintf(file, "%" PRIu64 " %" PRIu64 "\n", image->height, image->width);
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fprintf(file, "255\n");
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for (uint64_t y = 0; y < image->height; y++) {
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for (uint64_t x = 0; x < image->width; x++) {
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uint64_t position = (y * image->width) + x;
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ppm_rgb rgb = image->data[position];
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fprintf(file, "%" PRIu8 " %" PRIu8 " %" PRIu8, rgb.r, rgb.g, rgb.b);
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if (x != image->width - 1) {
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fprintf(file, " ");
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}
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}
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if (y != image->height - 1) {
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fprintf(file, "\n");
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}
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}
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fclose(file);
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return EXIT_SUCCESS;
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}
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int ppm_to_ppm6_file(ppm_image *image, const char *file_path) {
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FILE *file = fopen(file_path, "w");
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fprintf(file, "P6\n");
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fprintf(file, "%" PRIu64 " %" PRIu64 "\n", image->height, image->width);
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fprintf(file, "255\n");
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for (uint64_t y = 0; y < image->height; y++) {
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for (uint64_t x = 0; x < image->width; x++) {
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uint64_t position = (y * image->width) + x;
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ppm_rgb rgb = image->data[position];
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fprintf(file, "%c%c%c", rgb.r, rgb.g, rgb.b);
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}
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}
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fclose(file);
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return EXIT_SUCCESS;
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}
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int ppm_draw_point(ppm_image *image, uint64_t x, uint64_t y, ppm_rgb color) {
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if (ppm_is_in_bounds(image, x, y) == EXIT_FAILURE)
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return EXIT_FAILURE;
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uint64_t position = ((y - 1) * image->width) + x - 1;
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image->data[position] = color;
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return EXIT_SUCCESS;
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}
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int ppm_draw_circle(ppm_image *image, int x, int y, uint64_t radius,
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ppm_rgb color) {
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for (int local_y = 0; local_y <= radius * 2; local_y++) {
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for (int local_x = 0; local_x <= radius * 2; local_x++) {
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int local_centered_x = local_x - radius;
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int local_centered_y = local_y - radius;
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uint64_t length = sqrt((local_centered_x * local_centered_x) +
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(local_centered_y * local_centered_y));
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if (length > radius)
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continue;
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uint64_t global_x = local_x + x - radius;
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uint64_t global_y = local_y + y - radius;
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ppm_draw_point(image, global_x, global_y, color);
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}
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}
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return EXIT_SUCCESS;
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}
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int ppm_draw_rectangle(ppm_image *image, int x, int y, uint64_t height,
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uint64_t width, ppm_rgb color) {
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for (int local_y = 0; local_y <= height; local_y++) {
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for (int local_x = 0; local_x <= width; local_x++) {
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uint64_t global_x = local_x + x;
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uint64_t global_y = local_y + y;
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ppm_draw_point(image, global_x, global_y, color);
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}
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}
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return EXIT_SUCCESS;
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}
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/**
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* Draw a line using Bresenham's line algorithm.
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*/
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int ppm_draw_line(ppm_image *image, int x1, int y1, int x2, int y2,
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ppm_rgb color) {
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int dx = x2 - x1;
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int dy = y2 - y1;
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int d = 2 * dy - dx;
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int y = y1;
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for (int x = x1; x < x2; x++) {
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ppm_draw_point(image, x, y, color);
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if (d > 0) {
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y++;
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d -= 2 * dx;
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}
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d += 2 * dy;
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}
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return EXIT_SUCCESS;
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}
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int ppm_clear(ppm_image *image) {
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ppm_clear_with_background_color(image, PPM_BLACK);
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return EXIT_SUCCESS;
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}
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int ppm_clear_with_background_color(ppm_image *image,
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ppm_rgb background_color) {
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for (uint64_t y = 0; y < image->height; y++) {
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for (uint64_t x = 0; x < image->width; x++) {
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uint64_t position = (y * image->width) + x;
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image->data[position] = background_color;
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}
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}
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return EXIT_SUCCESS;
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}
+43
ppm.h
+43
ppm.h
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/**
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* PPM library for cr
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*/
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#ifndef PPM_H
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#define PPM_H
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#include <stdint.h>
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typedef struct {
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uint8_t r;
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uint8_t g;
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uint8_t b;
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} ppm_rgb;
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#define PPM_RED (ppm_rgb){255, 0, 0}
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#define PPM_GREEN (ppm_rgb){0, 255, 0}
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#define PPM_BLUE (ppm_rgb){0, 0, 255}
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#define PPM_WHITE (ppm_rgb){255, 255, 255}
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#define PPM_BLACK (ppm_rgb){0, 0, 0}
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typedef struct {
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uint64_t width;
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uint64_t height;
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ppm_rgb *data;
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} ppm_image;
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ppm_image *ppm_create(uint64_t height, uint64_t width);
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ppm_image *ppm_create_with_background_color(uint64_t height, uint64_t width,
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ppm_rgb background_color);
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int ppm_destroy(ppm_image *image);
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int ppm_to_ppm3_file(ppm_image *image, const char *file_path);
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int ppm_to_ppm6_file(ppm_image *image, const char *file_path);
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int ppm_draw_point(ppm_image *image, uint64_t x, uint64_t y, ppm_rgb color);
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int ppm_draw_circle(ppm_image *image, int x, int y, uint64_t radius,
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ppm_rgb color);
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int ppm_draw_rectangle(ppm_image *image, int x, int y, uint64_t height,
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uint64_t width, ppm_rgb color);
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int ppm_draw_line(ppm_image *image, int x1, int y1, int x2, int y2,
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ppm_rgb color);
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int ppm_clear(ppm_image *image);
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int ppm_clear_with_background_color(ppm_image *image, ppm_rgb background_color);
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#endif