Function overview

Functions are used to perform calculations or to read values. The distinction of a function from a command is the single returned value. Functions can be passed zero or more arguments, with each argument being separated by a comma. If no arguments are passed, the closing parenthesis is placed immediately after the opening parenthesis. Functions have the highest level of precedence aside from parenthesized statements. See sbs:page/docs-ptc-operator{Operator overview}. # Function table ## Mathematical functions |`ABS(number)`| Calculates the absolute value of a number.| |`ATAN(tangent)`| Calculates the arctangent of a value. Returns results in radians.| |`ATAN(y, x)`| Calculates the angle from the X-axis of a coordinate pair in radians.| |`COS(angle)`| Calculates the cosine of the given angle. `angle` is in radians.| |`DEG(radians)`| Converts an angle in radians into an angle in degrees.| |`EXP(exponent)`| Calculates e raised to the power of `exponent`| |`FLOOR(number)`| Rounds number to the next lowest integer| |`LOG(number)`| Calculates the natural logarithm of the number| |`PI()`| Returns the approximate value of pi. Returns 12867/4096, or about 3.141.| |`POW(base, exponent)`| Calculates the value of `base` raised to the power of `exponent`.| |`RAD(degrees)`| Converts an angle in degrees into an angle in radians.| |`RND(maximum)`| Generates a pseudorandom integer between 0 and `maximum`| |`SGN(number)`| Calculates the sign of the number.| |`SIN(angle)`| Calculates the sine of the given angle. `angle` is given in radians.| |`SQR(number)`| Calculates the square root of the number.| |`TAN(angle)`| Calculates the tangent of given angle. `angle` is given in radians.| ## String functions |`ASC(string)`| Returns the character code of the first character in the string.| |`CHR$(code)`| Returns a single character string corresponding to the character code.| |`HEX$(number)`| Converts a number into a hexadecimal string representation.| |`HEX$(number,digits)`| Converts a number into a hexadecimal string represnetation with a specific number of digits| |`INSTR(string, substring)`| Searches within a string for a substring, returning the index if found, or -1 if not found| |`INSTR(string, substring, start)`| Searches within a string for a substring starting from index `start`, returning the index `substring` is found at, or -1 if not found.| |`LEFT$(string, length)`| Returns a substring consisting of the `length` left-most characters| |`LEN(string)`| Returns the number of characters in the string| |`MID$(string, start, length)`| Returns a substring consisting of the `length` characters starting from index `start`.| |`RIGHT$(string, length)`| Returns a substring consisting of the `length` right-most characters.| |`STR$(number)`| Converts a number into a decimal string representation.| |`SUBST$(string, start, count, replacement)`| Returns a new string, replacing part of `string` with `replacement`.| |`VAL(string)`| Converts a string into a number.| ## System functions These are functions that interact with other subsystems of Petit Computer, such as the graphics or audio systems. ### Background |`BGCHK(layer)`| Checks if the BG layer specified is currently animated.| ### Audio |`BGMCHK()`| Checks if background music is playing on track 0.| |`BGMCHK(track)`| Checks if a specific background music track is in use.| |`BGMGETV(var)`| Gets the value of a MML variable.| |`TALKCHK()`| Checks if the speech synthesis system is currently active. On English copies of Petit Computer, always returns 0.| ### User input |`BTRIG()`| Checks if a button is pressed, with repeat checking. Identical to BUTTON(1).| |`BUTTON()`| Checks if a button is currently pressed.| |`BUTTON(type)`| Checks buttons pressed, held, or released depending on type.| |`INKEY$()`| Retrieve character input from the keyboard| ### Console |`CHKCHR(x, y)`| Gets the character code of a location on the text console.| ### Graphics |`GSPOIT(x, y)`| Gets the color of a location on the graphics page| |`GSPOIT(x, y, page)`| Gets the color of a location on a specific graphics page| ### Panel |`ICONCHK()`| Checks if a panel icon is pressed| ### Sprite |`SPCHK(id)`| Checks the animationstatus of a sprite.| |`SPGETV(id, var)`| Gets the value of a sprite variable.| |`SPHIT(id)`| Checks for collisions between the sprite `id` with other sprites. Returns 1 if there is a collision, and sets some system variables.| |`SPHIT(id, start)`| Checks for collisions between sprite `id` and sprites with IDs greater than `start`. Returns 1 if there is a collision, and sets some system variables.| |`SPHITRC(id, x, y, width, height)`| Checks for collision between a sprite and a rectangular region.| |`SPHITRC(id, x, y, width, height, dx, dy)`| Checks for collision between a sprite and a rectangular region, accounting for motion of the rectangle.| |`SPHITSP(id, other)`| Checks for collision between two specific sprites, returning 1 if collision occurs.|