1. /**
2.  * Names: Luke Whipple and Colton Johnson and David Dubchakov
3.  *
4.  * Some image manioulation functions for an array of pixels
5.  */
6.  
7. #include <stdlib.h>
8. #include <stdio.h>
9. #include <math.h>
10. #define STB_IMAGE_IMPLEMENTATION
11. #include "stb_image.h"
12.  
13. #define STB_IMAGE_WRITE_IMPLEMENTATION
14. #include "stb_image_write.h"
15.  
16. #include "imageUtils.h"
17.  
18. Pixel **loadImage(const char *filePath, int *height, int *width) {
19.   int x,y,n;
20.   unsigned char *data = stbi_load(filePath, &x, &y, &n, 4); //4 = force RGBA channels
21.   *height = y;
22.   *width = x;
23.  
24.   //contiguous allocation:
25.   Pixel **image = (Pixel **)malloc(sizeof(Pixel *) * y);
26.   image[0] = (Pixel *)malloc(sizeof(Pixel) * (y * x));
27.   for(int i=1; i<y; i++) {
28.     image[i] = (*image + (x * i));
29.   }
30.  
31.   int rowIndex = 0;
32.   int colIndex = 0;
33.   for(int i=0; i<(x * y * 4); i+=4) { //for each row
34.       image[rowIndex][colIndex].red   = data[i+0];
35.       image[rowIndex][colIndex].green = data[i+1];
36.       image[rowIndex][colIndex].blue  = data[i+2];
37.       colIndex++;
38.       if(colIndex == x) {
39.         //go to next row, reset column
40.         rowIndex++;
41.         colIndex=0;
42.       }
43.   }
44.   stbi_image_free(data);
45.   return image;
46. }
47.  
48. void saveImage(const char *fileName, Pixel **image, int height, int width) {
49.  
50.   // Convert height x width Pixel array to single array with
51.   // 3 (RGB) channels, ignoring the alpha channel and assume 100% opaque
52.   unsigned char *data = (unsigned char *) malloc(height * width * 3);
53.   int x = 0;
54.   for(int i=0; i<height; i++) {
55.     for(int j=0; j<width; j++) {
56.       data[x+0] = image[i][j].red;
57.       data[x+1] = image[i][j].green;
58.       data[x+2] = image[i][j].blue;
59.       x+=3;
60.     }
61.   }
62.   //write
63.   stbi_write_jpg(fileName, width, height, 3, data, 100);
64.   free(data);
65.   return;
66. }
67.  
68. Pixel ** copyImage(Pixel ** image, int height, int width) {
69.   if ((height <= 0) || (width <= 0) || (image == NULL)) {
70.     return (NULL);
71.   }
72.   Pixel ** copy = NULL;
73.   copy = (Pixel ** ) malloc(sizeof(Pixel) * height);
74.   for (int k = 0; k < height; k++) {
75.     copy[k] = (Pixel * ) malloc(sizeof(Pixel) * width);
76.   }
77.  
78.   int i = 0;
79.   int j = 0;
80.   for (i = 0; i < height; i++) {
81.     for (j = 0; j < width; j++) {
82.       copy[i][j] = image[i][j];
83.     }
84.   }
85.   return (copy);
86. }
87.  
88. void flipHorizontal(Pixel ** image, int height, int width) {
89.  
90.   for (int i = 0; i < height; i++) {
91.     for (int n = 0; n < (width / 2); n++) {
92.  
93.       Pixel placeHolder = image[i][n];
94.  
95.       image[i][n] = image[i][width - 1 - n];
96.  
97.       image[i][width - 1 - n] = placeHolder;
98.     }
99.   }
100. }
101.  
102. /**
103.      *  for (i = 0; i < (NUM_ELEMENTS / 2); ++i) {
104.       tempVal = userVals[i];                        // Temp for swap
105.       userVals[i] = userVals[NUM_ELEMENTS - 1 - i]; // First part of swap
106.       userVals[NUM_ELEMENTS - 1 - i] = tempVal;     // Second complete
107.    }
108. */
109.  
110. //TODO: implement
111.  
112. void flipVertical(Pixel ** image, int height, int width) {
113.  
114.   for (int i = 0; i < width; i++) {
115.     for (int n = 0; n < (height / 2); n++) {
116.  
117.       Pixel placeHolder = image[n][i];
118.  
119.       image[n][i] = image[height - 1 - n][i];
120.  
121.       image[height - 1 - n][i] = placeHolder;
122.     }
123.   }
124. }
125.  
126. Pixel ** rotateClockwise(Pixel ** image, int height, int width) {
127.  
128.   int placeHolder = height;
129.   height = width;
130.   width = placeHolder;
131.  
132.   Pixel ** rotate = NULL;
133.   rotate = (Pixel ** ) malloc(sizeof(Pixel) * height);
134.   for (int k = 0; k < height; k++) {
135.     rotate[k] = (Pixel * ) malloc(sizeof(Pixel) * width);
136.   }
137.  
138.   for (int i = 0; i < height; i++) {
139.     for (int j = 0; j < width; j++) {
140.       rotate[i][j] = image[j][i];
141.     }
142.  
143.     //TODO: implement
144.   }
145.  
146.   flipHorizontal(rotate, height, width);
147.  
148.   placeHolder = height;
149.   height = width;
150.   width = placeHolder;
151.  
152.   return (rotate);
153. }