images.h/images/images.c

#include <stdlib.h>
#include <stdio.h>
#include "images.h"


int image_new(int width, int height, Image* img) {
    //Image img = malloc(sizeof(Image));

    if (img == NULL) return 0;

    img->height = height;
    img->width = width;

    // initialize bitmap...
    img->bitmap = malloc(height * sizeof(int*));
    for (int i = 0; i < height; i++) {
        img->bitmap[i] = malloc(3 * width * sizeof(int));
    }

    //*image = *img;
    return 1;
}

int image_set_px(Image image, int x, int y, int r, int g, int b) {
    if (!image_check_coords(image, x, y)) return 0;

    image.bitmap[y][(3 * x) + 0] = (char) r;
    image.bitmap[y][(3 * x) + 1] = (char) g;
    image.bitmap[y][(3 * x) + 2] = (char) b;

    return 1;
}
int image_set_px_c(Image image, int x, int y, Color color) {
    if (!image_check_coords(image, x, y)) return 0;

    if (color.alpha == 0) return 1;

    if (color.alpha == 1) {
        image.bitmap[y][(3 * x) + 0] = color.r;
        image.bitmap[y][(3 * x) + 1] = color.g;
        image.bitmap[y][(3 * x) + 2] = color.b;
    } else { 
        
        //printf("adding %d to %f\n",  (color.alpha * color.r), ((1.0f - color.alpha) * (image.bitmap[y][(3 * x) + 0]/*  & 0x000000ff */)));

        image.bitmap[y][(3 * x) + 0] = (color.alpha * (color.r/*  & 0x000000ff */)) + ((1.0f - color.alpha) * (image.bitmap[y][(3 * x) + 0]/*  & 0x000000ff */));
        image.bitmap[y][(3 * x) + 1] = (color.alpha * (color.g/*  & 0x000000ff */)) + ((1.0f - color.alpha) * (image.bitmap[y][(3 * x) + 1]/*  & 0x000000ff */));
        image.bitmap[y][(3 * x) + 2] = (color.alpha * (color.b/*  & 0x000000ff */)) + ((1.0f - color.alpha) * (image.bitmap[y][(3 * x) + 2]/*  & 0x000000ff */));
    }

    return 1;
}

int image_check_coords(Image image, int x, int y) {
    return x >= 0 && x < image.width && 
           y >= 0 && y < image.height;
}

int image_destroy(Image image) {
    for (int i = 0; i < image.height; i++) {
        free(image.bitmap[i]);
    }
    free(image.bitmap);

    return 1;
}


///////// Colors

Color color_new(int r, int g, int b) {
    Color c;
    c.r = r;
    c.g = g;
    c.b = b;
    c.alpha = 1;
    return c;
}

Color color_new_alpha(int r, int g, int b, float alpha) {
    Color c;
    c.r = r;
    c.g = g;
    c.b = b;
    c.alpha = alpha;
    return c;
}

void print_color(Color c) {
    printf("color is: #%02hhX%02hhX%02hhX\n", c.r, c.g, c.b);
}

Color color_mix(Color c1, Color c2, float ratio) {
    return color_new_alpha(
        ratio * c1.r     + ((1 - ratio) * c2.r),
        ratio * c1.g     + ((1 - ratio) * c2.g),
        ratio * c1.b     + ((1 - ratio) * c2.b),
        ratio * c1.alpha + ((1 - ratio) * c2.alpha)
    );
}




//// IMAGE DRAWING HELPERS

int image_draw_rect(Image image, int x1, int y1, int x2, int y2, Color color) {
    int retval = 1;
    int y;
    for (; x1 < x2; x1++) {
        for (y = y1; y < y2; y++) {
            if (!image_set_px_c(image, x1, y, color)) retval = 0;
        }
    }

    return retval;
}

int image_draw_circ(Image image, int x, int y, int r, Color color) {
    int retval = 1;
    int i, j, r2 = r * r;
    for (i = -r+1; i < r; i++) {
        for (j = -r+1; j < r; j++) {
            if (i*i + j*j >= r2) continue;
            if (!image_set_px_c(image, x + i, y + j, color)) retval = 0;
        }
    }
    return retval;
}

int image_draw_square(Image image, int x, int y, int size, Color color) {
    int retval = 1;
    int i, j;
    for (i = -size / 2; i <= size / 2; i++) {
        for (j = -size / 2; j <= size / 2; j++) {
            if (!image_set_px_c(image, x + i, y + j, color)) retval = 0;
        }
    }
    return retval;
}