I am trying to make a program where I can use the arrow keys or the WASD keys to move a character across the screen (rpg style). I dont have any clue how to redraw the board in an easy way since there would be so many possible positions. I was thinking about creating a 2d array which would hold the positions. I am not asking for you all to write the code, I am asking simply. Is it possible to make the text character move along positions across the array?
One way would be to clear the "screen" and redraw the "map" at every change. Another might be to only redraw the lines that have changed. Yet another might be to position the cursor after the character you want to "move", print a backspace followed by e.g. a space, then reposition the cursor to after where you want the new character to be, print another backspace and then the character.
Or simply use a library such as ncurses.
On Windows, you can use the SetConsoleCursorPosition function to move the cursor to any arbitrary XY coordinates that you like.
TO do this, you need a HANDLE to the console, which is fairly easy to get
HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
More Windows Console functions.
See here for an example
Related
I've got this sfml window that displays a text and now I want to make it markable so that you can copy the text.
Any ideas how to do that?
If you just want to copy everything then just use
sf::Clipboard::setString(your_string_here);
If you want more features, here are some I implemented when I programmed a Code Editor in SFML.
I stored two indexes, the first is where the selection begins, and the second is where the section ends.
So in the string Hello World!, if you wanted to select World you would set the begin index to 6, and the end index to 10 or 11 (depending on whether you include the final character or not).
I render this using an sf::RectangleShape, since my editor supported multiple line selection boxes the code is more complicated, but for your example you would want to get the position of each character. I used my own text renderer, but SFML's sf::Text::findCharacterPos() should be able to help with that.
Next the copy part, this is just
sf::Clipboard::setString(getSelected());
where getSelected() is
return std::string::substr(selection_begin, selection_end - selection_begin);
If you want pasting as well then it is also simple:
eraseSelected();
insertStringAtCursor(sf::Clipboard::getString());
Which are both simple string operations as well (std::string::erase and reset the selection indexes, and std::string::insert).
Finally, to let the user change what is selected, either holding shift and pressing the arrow keys or clicking and dragging are both common ways, the former being easier than the latter.
For the former, check if shift is held and then if left or right is pressed update the indexes.
For the latter, you will need to handle mouse events and dragging. When dragging begins, set one of the indexes, whilst the mouse is moving and is dragging set the other index.
For university, we need to make a game in Unity that is controlled with an Arduino. My idea was a hacking game where the Arduino acts as the 'hacking device' when hacking something in the game. The arduino would have a screen and on that screen would be a basic command-line interface that lets me input simple commands to 'hack' but I've been having trouble regarding text and clearing it.
I've been able to use unity to send typed characters to the display as-well as a backspace function (pressing backspace would remove last character in the string)
I first had issue with clearing all the text when writing (calling tft.print doesn't clear any previous text). I was using fillScreen which was slow. I found out setTextColor had a second argument that let me just set all certain colored text to a different color. Setting it to black would essentially clear it.
This made it update pretty much instantly when writing to the screen but I now had a new issue, backspace would no longer would.
My understand is that when removing the character, it's color won't be updated when calling setTextColor leaving it on the screen until a restart/fillScreen is called.
I'm not really sure how to solve this and all google searches turn up little to no help.
Here's my code for updating the text:
void updateString(char c){
tft.setTextColor(WHITE,BLACK);
if(c!='<'){
//Add new character to end of string
str.concat(String(c));
}
else if(c=='<' && str.length()>2){
//Remove last character in string
str.remove(str.length()-1);
}
//Set cursor back to 0,0
tft.setCursor(0,0);
//Display text
tft.print(str);
}
I'd appreciate any help.
Maybe, use a similar function to tft.clear() each time you refresh the screen or you can draw a filled square of the background on the text so it looks like it has been erased then you rewrite the text.
Sounds like you are using proportionally-spaced fonts instead of the original classic fonts that ships with Adafruit_GFX. Historically, when using the default classic fonts one could set the background color option of the text to the same color as the background of the screen (usually black). This would overwrite the old screen contents with new data and work because the characters using the classic fonts are a uniform size. When using proportionally-spaced fonts, the background color option for the font is disabled by design.
This was presumably because of memory requirements and speed on slower AVR's. Regardless, when using proportionally-spaced fonts the background color feature won't work due to non-uniform sized characters overlapping the same regions as adjacent characters.
There are two work-arounds to this. Adafruit says in order to replace previously drawn text when using custom fonts you can either:
Use getTextBounds() to determine the smallest rectangle that encloses a
string and then erase that area using fillRect() prior to drawing
the new text. OR
Create an offscreen bitmap using GFXcanvas1 for a fixed size area,
draw the text in the GFXcanvas1 object and then copy to the screen
using drawBitmap().
Note that options 1 & 2 above are mutually exclusive. The second method requires more memory. The first method isn't perfect and produces some small amount of flicker, but is in general acceptable if coded carefully.
I hope that I have understood what the nature of your problem is and answered it in a satisfactory manner. If nothing else, at least now you know why custom font's will not work with the so called background color feature that works with the original 'classic' Adafruit fonts.
Nikki Cooper
I'd like to ask what's the simplest way of writing the chess unicode characters in a console window in C++? (♙♘♗♖♕♔♟♞♝♜♛♚) They are part of the "Miscellaneous Symbols" block in unicode. https://en.wikipedia.org/wiki/Chess_symbols_in_Unicode
I also want to print characters with square size, right now my chess board is not square, because each character is a rectangle and not a square.
It'd also be good to be able to write with ordinary non-square characters below the chess board, but that might be impossible? To mix different fonts/formattings in the same console window?
Ok, thanks in advance! :)
The first part of your question, outputting those characters, is platform-dependent. Linux consoles often use UTF-8, if that is the case you can encode the characters as UTF-8 and write them to standard output. On Windows you can use the Console API (the WriteConsole function):
HANDLE handle = GetStandardHandle(STD_OUTPUT_HANDLE);
DWORD written = 0;
// explicitly call the wide version (which always accepts UTF-16)
WriteConsoleW(handle, L"\u2658", 1, &written, NULL);
One caveat which is hard to work around is that you need a console font containing those characters.
For getting square cells, this is dependent on a lot of specifics about the way the console renders text. If it uses font substitution, then there is a chance the text will not actually be monospaced.
Now, if you have a console font with these characters, and if that font is monospaced, then you may be able to draw a square board by adding some spacing between the characters. You can use block elements like ▌ U+258C — LEFT HALF BLOCK to draw the chequerboard: ▌♘▐█▌ ▐.
I am creating a custom single line edit control, with a custom font in win32 api on windows 7, the font is not a fixed width font, and I need to move caret according to the mouse click, The edit control is not empty and if I know the horizontal position of the mouse click within the window, how do I calculate the number of characters after which I need to move caret to ?
I really am out of ideas, if it was a fixed width font, I would have divided the horizontal mouse click position with average character width, that would have been simpler, doing the same with not a fixed width font, is prone to errors.
Given that it's a single-line control, you probably don't plan on working with immensely long input (at least normally). That being the case, one possibility would be to just store the character positions in an array (or vector, etc.) Then you can use (for example) a binary search in that array to find character positions. Of course, you can do the same even for longer strings--though it can increase storage requirements quite a bit.
This is a familiar problem. You are in essence trying to do hit testing on text and for that you need the location on the screen of each character of the text.
My preferred strategy is to calculate an array of RECT, one for each character of displayed text. The array needs to be updated when text is added or deleted, but it easily handles single or multiple lines. The function GetCharWidth32 retrieves all the widths for a string of text in a particular font selected into a DC. For single line one call is enough, and calculating the array of RECTs is simple. It's not much harder to do multiline.
Handle the mouse down message, loop through the array and find the right character. A brute force search is plenty fast enough.
This method is simple and easily generalises to a range of similar problems.
I am using SDL and libfreetype and constructing a very basic GUI, I'm implementing a textBox, but I haven't been able to figure out how I'm supposed to generate the standard blinking cursor part. It doesn't seem to be exactly the same as a | character. And moreover if I draw it as a | character that changes the text width.
What's the canonically correct way to render text in a textbox with a cursor?
The easiest way is to just draw a line primitive, this gives you a lot more control over the spacing, length and width of the caret.
And if you want to keep it as a text character in your font system, you can do a render-to-texture and copy it out, or do a simple memory blit onto your font atlas (so you can can keep pipe character separate, an use a control char like 0x01 for the caret).