The goal of this is to have a variable, AutonNumber, that changes when you press something on the brain screen. Then in autonomous, we can read this number and run different autonomous modes depending on what we selected.
The goal is to have eight rectangles that we can select that changes AutonNumber.
The brain screen is 480 x 240. If we want 8 rectangles, each rectangle can take up 60 pixels. In the image above, the rectangles are 50 pixels wide with a little space between each one.
The drawRectangle() command prints a rectangle at x1, y1, x2, y2. This function would print the first rectangle. x2 and y2 are relative from x1 y1.
void pre_auton() {
// Initializing Robot Configuration. DO NOT REMOVE!
vexcodeInit();
Brain.Screen.setPenColor(blue);
Brain.Screen.drawRectangle(5, 50, 50, 175, blue);
}To print multiple rectangles, we can copy/paste this, but increase x1 by 60 every time.
void pre_auton() {
// Initializing Robot Configuration. DO NOT REMOVE!
vexcodeInit();
Brain.Screen.setPenColor(blue);
Brain.Screen.drawRectangle(5, 50, 50, 175, blue);
Brain.Screen.drawRectangle(5+60, 50, 50, 175, blue);
Brain.Screen.drawRectangle(5+120, 50, 50, 175, blue);
Brain.Screen.drawRectangle(5+180, 50, 50, 175, blue);
Brain.Screen.drawRectangle(5+240, 50, 50, 175, blue);
Brain.Screen.drawRectangle(5+300, 50, 50, 175, blue);
Brain.Screen.drawRectangle(5+360, 50, 50, 175, blue);
Brain.Screen.drawRectangle(5+420, 50, 50, 175, blue);
}It is bad practice to copy/paste code like this because it is difficult to maintain. If you want to change the size of the rectangle a little, you need to go through every line of code and modify it, making it extremely easy to make a mistake.
We can use a for loop and simplify this code. I would try to explain for loops, but this interactive tutorial does a better job then I will.
In the code above, each time we print a new rectangle, we are adding 60*x to 5. So in the for loop, we can add 60*i. The first time it runs, 60*0 is 0 so it will just print at 5. The second time it runs, 60*1 is 60 so it will print at 65. This is the same as the code above.
void pre_auton() {
// Initializing Robot Configuration. DO NOT REMOVE!
vexcodeInit();
for (int i = 0; i < 8; i++) {
Brain.Screen.setPenColor(blue);
Brain.Screen.drawRectangle(5+(60*i), 50, 50, 175, blue);
}
}After the selection boxes are printed, we will run a while loop to find what pixel was pressed.
We need to check which box the selection was within. All of the selections have the same up/down bound, where the selection can be within 50 (y1) and 175 (y2). We can read selected positions with
int AutonNumber = 1;
void pre_auton() {
// Initializing Robot Configuration. DO NOT REMOVE!
vexcodeInit();
for (int i = 0; i < 8; i++) {
Brain.Screen.setPenColor(blue);
Brain.Screen.drawRectangle(5+(60*i), 50, 50, 175, blue);
}
while (true) {
// Selected position
int x = Brain.Screen.xPosition();
int y = Brain.Screen.yPosition();
if (50 < y && y < 50+175 && 5 < x && x < 55) {
// First Box
AutonNumber = 1;
}
else if (50 < y && y < 50+175 && 65 < x && x < 115) {
// Second Box
AutonNumber = 2;
}
else if (50 < y && y < 50+175 && 125 < x && x < 175) {
// Third Box
AutonNumber = 3;
}
else if (50 < y && y < 50+175 && 185 < x && x < 235) {
// Fourth Box
AutonNumber = 4;
}
else if (50 < y && y < 50+175 && 245 < x && x < 295) {
// Fifth Box
AutonNumber = 5;
}
else if (50 < y && y < 50+175 && 305 < x && x < 355) {
// Sixth Box
AutonNumber = 6;
}
else if (50 < y && y < 50+175 && 365 < x && x < 415) {
// Seventh Box
AutonNumber = 7;
}
else if (50 < y && y < 50+175 && 425 < x && x < 475) {
// Eighth Box
AutonNumber = 8;
}
wait(20, msec);
}
}But again, we have this copy/pasted nightmare! We can fix this in the same way we did before, by using a for loop.
The y checks for all the boxes are the same, so we don't need to run the for loop until we know the selection is within that y.
The x is checking 5+(60*i) for the first one, and (60*(i+1))-5.
int AutonNumber = 1;
void pre_auton() {
// Initializing Robot Configuration. DO NOT REMOVE!
vexcodeInit();
for (int i = 0; i < 8; i++) {
Brain.Screen.setPenColor(blue);
Brain.Screen.drawRectangle(5+(60*i), 50, 50, 175, blue);
}
while (true) {
// Selected position
int x = Brain.Screen.xPosition();
int y = Brain.Screen.yPosition();
if (50 < y && y < 50+175) {
for (int i = 0; i < 8; i++) {
if (5+(60*i) < x && x < (60*(i+1))-5) {
AutonNumber = i+1;
}
}
}
wait(20, msec);
}
}To print text to the screen we first need to define a font using setFont. This only needs to happen once, and should be before the while loop.
Then to set text, we can use Brain.Screen.printAt(). After writing text we need a delay (every loop needs a delay to avoid wasting the brains resources), and after the delay we can clear the text to allow the text to update.
int AutonNumber = 1;
void pre_auton() {
// Initializing Robot Configuration. DO NOT REMOVE!
vexcodeInit();
for (int i = 0; i < 8; i++) {
Brain.Screen.setPenColor(blue);
Brain.Screen.drawRectangle(5+(60*i), 50, 50, 175, blue);
}
Brain.Screen.setFont(monoM);
while (true) {
// Selected position
int x = Brain.Screen.xPosition();
int y = Brain.Screen.yPosition();
if (50 < y && y < 50+175) {
for (int i = 0; i < 8; i++) {
if (5+(60*i) < x && x < (60*(i+1))-5) {
AutonNumber = i+1;
}
}
}
Brain.Screen.printAt(5, 30, "Current Auto: %d", AutonNumber); // %d is a formatting character that gets replaced with AutonNumber
wait(20, msec);
Brain.Screen.clearLine(1);
}
}void autonomous(void) {
if (AutonNumber == 1) {
// Call Auton
}
else if (AutonNumber == 2) {
// Call Auton
}
else if (AutonNumber == 3) {
// Call Auton
}
else if (AutonNumber == 4) {
// Call Auton
}
else if (AutonNumber == 5) {
// Call Auton
}
else if (AutonNumber == 6) {
// Call Auton
}
else if (AutonNumber == 7) {
// Call Auton
}
else if (AutonNumber == 8) {
// Call Auton
}
}