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  1. # This file provides some common functionality for the main scripts.  It is
  2. # designed to be sourced, rather than executed.
  3.  
  4. # Makes the script more robust in general.
  5. set -o errexit
  6. set -o nounset
  7. set -o pipefail
  8.  
  9. # ANSI escape codes for pretty terminal colors.
  10. readonly GREEN='\033[32;1m'
  11. readonly YELLOW="\033[33;1m"
  12. readonly RED="\033[31;1m"
  13. readonly RESET="\033[0m"
  14.  
  15. # Gives the user a "yes/no" prompt with the text from the first positional
  16. # parameter (if given).  If an affirmative response is received,
  17. # returns success; if a negative response is received, returns failure; if an
  18. # unrecognized response is received, the user is given the prompt again.  This
  19. # function always outputs to the terminal rather than stdout, so it is safe
  20. # to use from within functions that are expected to output their results.
  21. Prompt()
  22. {
  23.     # Only try to output the prompt message if it is given, so no newline is
  24. 	# printed if it isn't.
  25. 	[ $# -gt 0  ] && echo -e "$1" > /dev/tty
  26.  
  27. 	local Response
  28. 	echo -en "[${GREEN}Y${RESET}/${RED}N${RESET}] " > /dev/tty
  29. 	read Response
  30.  
  31. 	# For case insensitivity.
  32. 	Response="$(echo "$Response" | tr [A-Z] [a-z])"
  33.  
  34. 	if [[ "$Response" =~ ^y(es)?$ ]]; then true
  35. 	elif [[ "$Response" =~ ^no?$ ]]; then false
  36. 	else
  37. 		echo "I don't understand that response.  Try \"yes\" or \"no.\"" > /dev/tty
  38. 		# Keep pestering the user until he gives a valid response.
  39. 		Prompt
  40. 	fi
  41. }; readonly -f Prompt
  42.  
  43. # Outputs a string of shell code that will parse the program arguments for long options.
  44. # Example:
  45. #   # Let's say that the program was passed the arguments --One Two --Three.
  46. #   eval "$(OptionParser One Two Three)"
  47. #   echo $One # True.
  48. #   echo $Two # False.  The argument was not preceded by "--" on the command-line.
  49. #   echo $Three # False.  OptionParser stops on the first argument that isn't an
  50. #               # option, and Two wasn't an option.
  51. OptionParser()
  52. {
  53. 	if [ $# -ge 1 ]; then
  54. 		for OptionName in "$@"; do echo -n "$OptionName=false; "; done
  55. 		echo -n 'while [ $# -ge 1 ]; do case "$1" in'
  56. 		for OptionName in "$@"; do
  57. 			echo -n " '--$OptionName') $OptionName=true && shift ;;"
  58. 		done
  59. 		echo -n ' *) break ;; esac; done'
  60. 	fi
  61. }; readonly -f OptionParser
Success #stdin #stdout 0s 5292KB
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stdin
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#include <iostream>
#include <cmath>
#include <cstring>
#include <unistd.h>

int main() {
    const int width = 80;
    const int height = 22;
    const float R1 = 1.0f;
    const float R2 = 2.0f;
    const float K2 = 5.0f;
    const float K1 = width * K2 * 3 / (8 * (R1 + R2));

    char buffer[height][width];
    float zbuffer[height][width];
    
    float A = 0.0f, B = 0.0f;

    while (true) {
        std::memset(buffer, '0', sizeof(buffer));
        std::memset(zbuffer, 0, sizeof(zbuffer));

        float cosA = cos(A), sinA = sin(A);
        float cosB = cos(B), sinB = sin(B);

        // Iterate through torus angles
        for (float theta = 0; theta < 6.28318f; theta += 0.07f) {
            float costheta = cos(theta), sintheta = sin(theta);
            
            for (float phi = 0; phi < 6.28318f; phi += 0.02f) {
                float cosphi = cos(phi), sinphi = sin(phi);
                
                // 3D coordinates before rotation
                float circlex = R2 + R1 * costheta;
                float circley = R1 * sintheta;

                // 3D coordinates after rotation
                float x = circlex * (cosB * cosphi + sinA * sinB * sinphi) - circley * cosA * sinB;
                float y = circlex * (sinB * cosphi - sinA * cosB * sinphi) + circley * cosA * cosB;
                float z = K2 + cosA * circlex * sinphi + circley * sinA;
                float ooz = 1.0f / z;  // Perspective projection

                // 2D screen coordinates
                int xp = static_cast<int>(width / 2 + K1 * ooz * x);
                int yp = static_cast<int>(height / 2 - K1 * ooz * y);

                // Update buffer if point is visible
                if (xp >= 0 && xp < width && yp >= 0 && yp < height && ooz > zbuffer[yp][xp]) {
                    zbuffer[yp][xp] = ooz;
                    buffer[yp][xp] = '1';
                }
            }
        }

        // Display frame
        std::cout << "\x1b[H";
        for (int j = 0; j < height; j++) {
            for (int i = 0; i < width; i++) {
                std::cout << buffer[j][i];
            }
            std::cout << '\n';
        }

        // Update angles
        A += 0.07f;
        B += 0.03f;
        
        // Frame delay (30ms)
        usleep(30000);
    }

    return 0;
}
stdout
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Standard output is empty
https://ideone.com/xwbDPY
language:
Bash (bash 5.0.3)
created:
2 days ago
visibility:
public

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