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#include<stdio.h>
#include<string.h>
#include<stdint.h>
/* map holding the pixels for a 200x200 pixel imagebuffer, [x][y]
* bits are in braille order within each byte
*/
uint8_t map[100][50];
/* takes char storing the on/off positions of 8 points, in braille encoding
* order, and prints the corresponding braille char
*/
/* global state bit switch */
uint8_t state = 1;
#define STATE_LOOP 0x01
void printbraille(uint8_t points) {
/* outputs braille characters, the encoding for braile is:
* 1 4
* 2 5
* 3 6
* 7 8
* with the block being in U+2800 to U+28FF
* in utf8 that's encoded
* 1110xxxx 10xxxxxx 10xxxxxx
* [1110](0010) [10](1000)87 [10]654321
*/
printf("%c%c%c",
0b11100010,
0b10100000 | (points >> 6),
0b10000000 | (points & 0b00111111));
}
/* prints the map, clears output before aswell*/
void printmap() {
uint8_t xi = 0;
uint8_t yi = 0;
/*terminal escape code to move the cursor to beginning of screen or 1,1*/
printf("\033[1;1H");
while (yi < 50) {
xi = 0;
while (xi < 100) {
printbraille(map[xi][yi]);
xi++;
}
printf("\n");
yi++;
}
}
/* sets a pixel in the map, converts x,y coordinates to braille order
* if set is 0, then set it to 0
* if 1, set to 1
* if > 1, flip
* does not throw errors
*/
void setpixel(uint8_t x, uint8_t y,uint8_t set) {
/* anchor x and y coordinates, eg the index in map*/
uint8_t ax;
uint8_t ay;
/*bitmask in braille order of the byte in mask*/
uint8_t shift = 0x01;
/* check if out of bounds, since the arguments are unsigned, don't have
* to check below 0, doesn't throw errors
*/
if ( (x >= 200 ) || (y >= 200) ) {
return;
}
/* integer division rounds down, therefore dividing will always get the
* index
*/
ax = x/2;
ay = y/4;
/*
* maps to braille order based off of x and y offsets
* 1 4
* 2 5
* 3 6
* 7 8
*/
switch(x % 2) {
case 0:
switch (y % 4) {
case 0:
shift = shift << 0;
break;
case 1:
shift = shift << 1;
break;
case 2:
shift = shift << 2;
break;
case 3:
shift = shift << 6;
break;
}
break;
case 1:
switch (y % 4) {
case 0:
shift = shift << 3;
break;
case 1:
shift = shift << 4;
break;
case 2:
shift = shift << 5;
break;
case 3:
shift = shift << 7;
break;
}
break;
}
/* sets the bit based on set*/
switch (set) {
case 0:
map[ax][ay] = map[ax][ay] & (~shift);
break;
case 1:
map[ax][ay] = map[ax][ay] | shift;
break;
default:
map[ax][ay] = ((~map[ax][ay]) & shift) |
((~shift) & map[ax][ay]);
break;
}
return;
}
/*takes two points and draws a line between them, dot specifies that every nth x
* point be drawn, if dot != 1, then a dotted line is drawn
*/
void drawline(uint8_t x1, uint8_t y1, uint8_t x2, uint8_t y2, uint8_t dot) {
/*temporary x and y for switching x1,y1 and x2,y1 if x1>x2*/
uint8_t tv;
/*number of x values to translate*/
uint8_t dx;
/*number of y values to translate*/
uint8_t dy;
/* for whether dy should be positive or negative, 1 pos, 0 neg*/
uint8_t dir;
/*drawin index*/
uint8_t xi = 0;
/*makes sure that x1 < x2, otherwise switch them arround*/
if (x1 > x2) {
tv = x1;
x1 = x2;
x2 = tv;
tv = y1;
y1 = y2;
y2 = tv;
}
dx = x2 - x1;
/*find absolute
* dir is used since i'm planning to port to a platform that may not
* have signed ints.
*/
if (y1 > y2) {
dir = 0;
dy = y1 - y2;
} else {
dir = 1;
dy = y2 - y1;
}
/*
*For vertical Lines
* Uses xi as a y index now
*/
if (x1 == x2) {
while (xi <= dy) {
if (dir) {
setpixel(x1, y1 + xi, 1);
} else {
setpixel(x1, y1 - xi, 1);
}
xi++;
}
}
/*
* loop through x and draws y in line, dots done with modulus.
*/
while (xi <= (dx)) {
if ((xi % dot) == 0) {
if (dir) {
setpixel(x1 + xi, y1 + ((dy/dx * xi)),1);
} else {
setpixel(x1 + xi, y1 - ((dy/dx * xi)) ,1);
}
}
xi++;
}
return;
}
int main (int argc, char * argv[]) {
/*holds keypress*/
char input;
/*zeroing map*/
memset(map, 0, sizeof(map[0][0]) * 100 * 50);
printmap();
while (state & STATE_LOOP) {
setpixel(10,20,2);
drawline(0,0,20,20,1);
drawline(0,40,10,20,1);
drawline(10,50,0,40,2);
drawline(10,0,10,200,1);
drawline(10,100,100,100,4);
printmap();
/* checks input*/
input = getc(stdin);
/*haven't set the terminal to raw mode so will still need
* space
*/
if (input == 'q') {
state = state & (~STATE_LOOP);
}
}
return 0;
}
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