Introduction

pico-Céu is a tiny programming environment for visual and interactive applications such as video games. It is composed of the programming language Céu and minimalist libraries for input, graphics, network, and sound.

Resources

Resource is any external file used by a pico-Céu application, such as images, fonts, and audio files. Every resource should be located in a res folder, in the root of the application, and can be used in GRAPHICS_DRAW_BMP, GRAPHICS_SET_FONT, or SOUND_PLAY.

Data Types

pico-Céu already provides some data types

Color

data Color with
    var integer r;
    var integer g;
    var integer b;
end

Parameters:
- integer: red component
- integer: green component
- integer: blue component

Example:

var Color color = val Color(255,1,1);
emit GRAPHICS_SET_COLOR_NAME(color);
emit GRAPHICS_DRAW_PIXEL(0,0);
emit GRAPHICS_SET_COLOR_RGB(color.r, color.g, color.b);
emit GRAPHICS_DRAW_PIXEL(1,1);

Point

data Point with
    var integer x;
    var integer y;
end

Parameters:
- integer: position in the x-axis
- integer: position in the y-axis

Example:

var Point pt = val Point(0,0);
emit GRAPHICS_DRAW_PIXEL(pt.x, pt.y);

Rect

data Rect with
    var integer x;
    var integer y;
    var integer w;
    var integer h;
end

Parameters:
- integer: position in the x-axis
- integer: position in the y-axis
- integer: rectangle width
- integer: rectangle height

Example:

var Rect rect = val Rect(0,0,4,5);
emit GRAPHICS_DRAW_RECT(rect.x, rect.y, rect.w, rect.h);

Graphics

Provides graphics operations, such as for drawing pixels and images on the screen.

TODO: axis

Configuration

GRAPHICS_SET_ANCHOR

Changes the drawing anchor of all subsequent drawing operations GRAPHICS_DRAW_BMP, GRAPHICS_DRAW_RECT, and GRAPHICS_DRAW_TEXT.

output (HAnchor,VAnchor) GRAPHICS_SET_ANCHOR;

Parameters:
- HAnchor: new horizontal anchor
- VAnchor: new vertical anchor

The anchor specifies the part of the shape to appear at the pixel position of the drawing operation.

The possible values for HAnchor are HANCHOR_LEFT, HANCHOR_CENTER, and HANCHOR_RIGHT. The initial value is HANCHOR_CENTER.

The possible values for VAnchor are VANCHOR_TOP, VANCHOR_CENTER, and VANCHOR_BOTTOM. The initial value is VANCHOR_CENTER.

GRAPHICS_SET_BMP_FRAME

Changes the drawing frame of all subsequent GRAPHICS_DRAW_BMP operations.

output (int?,int?) GRAPHICS_SET_BMP_FRAME;

Parameters:
- int?: new frame index to show (default: 0)
- int?: new number of frames in the image (default: 1)

The initial frame index is 0 and number of frames is 1.

GRAPHICS_SET_BMP_SIZE

Changes the drawing size of all subsequent GRAPHICS_DRAW_BMP operations.

output (int?,int?) GRAPHICS_SET_BMP_SIZE;

Parameters:
- int?: new width (default: proportional to new height)
- int?: new height (default: proportional to new width)

If both width and height are set to default, the new size is the original image size.

The initial size is the original image size.

GRAPHICS_SET_COLOR_NAME

Changes the color of all subsequent drawing operations.

output (Color) GRAPHICS_SET_COLOR_NAME

Parameters:
- Color: new color name

The color names are based on the HTML Web Colors:

https://en.wikipedia.org/wiki/Web_colors#HTML_color_names

The possible values are COLOR_WHITE, COLOR_SILVER, COLOR_GRAY, COLOR_BLACK, COLOR_RED, COLOR_MAROON, COLOR_YELLOW, COLOR_OLIVE, COLOR_LIME, COLOR_GREEN, COLOR_AQUA, COLOR_TEAL, COLOR_BLUE, COLOR_NAVY, COLOR_FUCHSIA, COLOR_PURPLE.

The initial color is white.

GRAPHICS_SET_COLOR_RGB

Changes the color in RGB of all subsequent drawing operations.

output (integer,integer,integer) GRAPHICS_SET_COLOR_RGB

Parameters:
- integer: new red component
- integer: new green component
- integer: new blue component

The initial color is white.

GRAPHICS_SET_FONT

Changes the font for drawing and writing text.

output (text,integer) GRAPHICS_SET_FONT

Parameters:
- text: path for the .ttf font filename
- integer: height of the new font in pixels

GRAPHICS_SET_SCALE

Changes the drawing scale of all subsequent drawing operations GRAPHICS_DRAW_BMP, GRAPHICS_DRAW_RECT, GRAPHICS_DRAW_TEXT, GRAPHICS_DRAW_INT, and GRAPHICS_DRAW_REAL.

output (real,real) GRAPHICS_SET_SCALE;

Parameters:
- real: new horizontal scale
- real: new vertical scale

The initial scale is 1.0 x 1.0.

GRAPHICS_SET_WRITE_CURSOR

Changes the cursor starting position for writing text with GRAPHICS_WRITE and GRAPHICS_WRITELN.

output (integer,integer) GRAPHICS_SET_WRITE_CURSOR

Parameters:
- integer: new position in the x-axis
- integer: new position in the y-axis

The initial starting position is the top-left of the screen.

The current position is reset on every WINDOW_CLEAR operation.

Drawing

GRAPHICS_DRAW_BMP

Draws a bitmap image on the screen.

output (integer,integer,text) GRAPHICS_DRAW_BMP

Parameters:
- integer: position in the x-axis
- integer: position in the y-axis
- text: path for the .bmp image filename

GRAPHICS_DRAW_PIXEL

Draws a pixel on the screen.

output (integer,integer) GRAPHICS_DRAW_PIXEL

Parameters:
- integer: position in the x-axis
- integer: position in the y-axis

The drawing color is specified with GRAPHICS_SET_COLOR_NAME or GRAPHICS_SET_COLOR_RGB.

GRAPHICS_DRAW_LINE

Draws a line on the screen.

output (integer,integer,integer,integer) GRAPHICS_DRAW_LINE;

Parameters:
- integer: start position in the x-axis
- integer: start position in the y-axis
- integer: end position in the x-axis
- integer: end position in the y-axis

The drawing color is specified with GRAPHICS_SET_COLOR_NAME or GRAPHICS_SET_COLOR_RGB.

GRAPHICS_DRAW_RECT

Draws a rectangle on the screen.

output (integer,integer,integer,integer) GRAPHICS_DRAW_RECT

Parameters:
- integer: position in the x-axis
- integer: position in the y-axis
- integer: rectangle width
- integer: rectangle height

The drawing color is specified with GRAPHICS_SET_COLOR_NAME or GRAPHICS_SET_COLOR_RGB.

GRAPHICS_DRAW_TEXT

Draws a text on the screen.

output (int,int,text) GRAPHICS_DRAW_TEXT;

Parameters:
- integer: position in the x-axis
- integer: position in the y-axis
- text: text to draw

The drawing font is specified with GRAPHICS_SET_FONT. The drawing color is specified with GRAPHICS_SET_COLOR_NAME or GRAPHICS_SET_COLOR_RGB.

GRAPHICS_DRAW_INT

Similar to GRAPHICS_DRAW_TEXT, but draws a integer on the screen.

output (int,int,int) GRAPHICS_DRAW_INT;

Parameters:
- integer: position in the x-axis
- integer: position in the y-axis
- int: int to draw

GRAPHICS_DRAW_REAL

Similar to GRAPHICS_DRAW_REAL, but draws a real on the screen.

output (int,int,real) GRAPHICS_DRAW_REAL;

Parameters:
- integer: position in the x-axis
- integer: position in the y-axis
- real: real to draw

Writing

GRAPHICS_WRITE

Writes a text on the screen.

output (text) GRAPHICS_WRITE;

Parameters:
- text: text to draw

The drawing position is first specified with GRAPHICS_SET_WRITE_CURSOR. The cursor advances automatically for the position after the text. The drawing font is specified with GRAPHICS_SET_FONT. The drawing color is specified with GRAPHICS_SET_COLOR_NAME or GRAPHICS_SET_COLOR_RGB.

GRAPHICS_WRITELN

Writes a line of text on the screen.

output (text) GRAPHICS_WRITELN;

The drawing position is first specified with GRAPHICS_SET_WRITE_CURSOR. The cursor advances automatically for the next line after the text, at the same initial position. The drawing font is specified with GRAPHICS_SET_FONT. The drawing color is specified with GRAPHICS_SET_COLOR_NAME or GRAPHICS_SET_COLOR_RGB.

Other

GRAPHICS_SCREENSHOT

Takes a screen shot.

output (text) GRAPHICS_SCREENSHOT

Parameters:
- text: path for the .bmp image filename to generate

Input Devices

Provides input handling, such as for keyboard and mouse.

Keyboard

KEY_PRESS

input (integer) KEY_PRESS

Occurrences:
- whenever a keyboard key is pressed
Payload:
- integer: numeric key code

Examples:

var int c = await KEY_PRESS;

_printf("%c\n", c);

var int c = await KEY_PRESS until c==KEY_a;

_printf("%c\n", c);

TODO: key codes

KEY_UNPRESS

input (integer) KEY_UNPRESS

Occurrences:
- whenever a keyboard key is released
Payload:
- integer: numeric key code

TODO: key codes

Mouse

MOUSE_CLICK

input (integer,integer,integer) MOUSE_CLICK

Occurrences:
- whenever a mouse button is pressed
Payload:
- integer: numeric button code
  - MOUSE_LEFT
  - MOUSE_MIDDLE
  - MOUSE_RIGHT
  - MOUSE_X1
  - MOUSE_X2
- integer: current mouse position in the x-axis
- integer: current mouse position in the y-axis

Example:

var int c;
var int x;
var int y;

(c,x,y) = await MOUSE_CLICK until c==MOUSE_LEFT;

_printf("(%d,%d)\n", x,y);

MOUSE_UNCLICK

input (integer,integer,integer) MOUSE_UNCLICK

Occurrences:
- whenever a mouse button is released
Payload:
- integer: numeric button code (same as MOUSE_CLICK)
- integer: current mouse position in the x-axis
- integer: current mouse position in the y-axis

MOUSE_MOVE

input (integer,integer) MOUSE_MOVE

Occurrences:
- whenever the mouse moves
Payload:
- integer: current mouse position in the x-axis
- integer: current mouse position in the y-axis

Sound

Provides sound playback.

Configuration

SOUND_SET_VOLUME

Changes the volume of all subsequent sound playbacks.

output (integer) SOUND_SET_VOUME

Parameters:
- integer: new sound volume in percentage (from 0 to 100)

Playback

SOUND_PLAY

Plays a sound file.

output (text) SOUND_PLAY

Parameters:
- text: path for the sound filename

The playback volume is specified with SOUND_SET_VOLUME.

Network

Provides unreliable broadcast communication between peers.

Send

NET_SEND

Broadcasts a message to all peers.

output (integer,byte&&) NET_SEND;

Parameters:
- integer: number of bytes to transmit
- byte&&: stream of bytes

Receive

NET_RECEIVE

Receives all messages from all peers, including itself.

input (integer,byte&&) NET_RECEIVE;

Occurrences:
- on every received message
Payload:
- integer: number of received bytes
- byte&&: stream of bytes

Usart

A pico-Céu library to send and receive data using USART (Universal Synchronous and Asynchronous Receiver-Transmitter). Windows-only for now.

Includes

 #include "usart.ceu"

Initiate

code/await Usart (var int portNumber) -> NEVER

Parameters:
- var int: Serial port number to use.
Example:

spawn Usart(3);

Specify that we'll use the COM3 port.

Send

Usart_TX

Send a byte vector via serial.

code/await Usart_TX (var&[] byte str) -> none

Parameters:
- var&[] byte: the byte vector to send.
Example:

spawn Usart(3);

var[5] byte str;
call String_Append_STR(&str, "send");

await Usart_TX(&str);

Create a string and send it via serial using Usart_TX. Check String_Append_STR to learn more string manipulation in Céu.

Receive

Usart_RX

code/await Usart_RX (var&[] byte str, var int nbChar) -> none

Payload:
- var&[] byte: byte vector to store the received data
- var int: number of bytes to read
Example:

spawn Usart(3);

var[5] byte buffer;
await Usart_RX(&buffer, 5);
String_Print(&buffer);

Receive a string of size 5 from serial port, counting the \0.

Frame Management

Manages the game frames, such as for updating animations and redrawing the screen.

Configuration

FRAMES_SET

Enables or disables the generation of periodic FRAMES_UPDATE and FRAMES_REDRAW inputs to the application.

output (yes/no) FRAMES_SET

Parameters:
- yes/no: new state
  - yes: enables the generation of frames
  - no: disables the generation of frames

Inputs

FRAMES_UPDATE

input (integer) FRAMES_UPDATE

Occurrences:
- on every frame, before FRAMES_REDRAW
Payload:
- integer: the number of milliseconds elapsed since the previous frame

FRAMES_REDRAW

input (none) FRAMES_REDRAW

Occurrences:
- on every frame, after FRAMES_UPDATE
Payload:
- none: no payload

Before the input occurs, the screen is automatically cleared with WINDOW_CLEAR.

Window Management

Manages the application window.

Configuration

WINDOW_SET_CLEAR_COLOR_NAME

Changes the background color of WINDOW_CLEAR.

output (Color) WINDOW_SET_CLEAR_COLOR_NAME

Parameters:
- Color: new color name

The color names are based on the HTML Web Colors:

https://en.wikipedia.org/wiki/Web_colors#HTML_color_names

The possible values are COLOR_WHITE, COLOR_SILVER, COLOR_GRAY, COLOR_BLACK, COLOR_RED, COLOR_MAROON, COLOR_YELLOW, COLOR_OLIVE, COLOR_LIME, COLOR_GREEN, COLOR_AQUA, COLOR_TEAL, COLOR_BLUE, COLOR_NAVY, COLOR_FUCHSIA, COLOR_PURPLE.

The default color is black.

WINDOW_SET_CLEAR_COLOR_RGB

Changes the background color of WINDOW_CLEAR in RGB.

output (integer,integer,integer) WINDOW_SET_CLEAR_COLOR_RGB

Parameters:
- integer: new red component
- integer: new green component
- integer: new blue component

The default color is black.

WINDOW_SET_GRID

Enables or disables a visual grid delimiting the screen pixels.

output (yes/no) WINDOW_SET_GRID

Parameters:
- yes/no: new state
  - yes: enables the grid
  - no: disables the grid

The ratio between the real and logical dimensions set with WINDOW_SET_SIZE must be greater then one.

The window is automatically cleared with WINDOW_CLEAR.

WINDOW_SET_SIZE

Changes the real and logical sizes of the window.

output (integer,integer,integer,integer) WINDOW_SET_SIZE

Parameters:
- integer: new real width
- integer: new real height
- integer: new logical width
- integer: new logical height

The window is automatically cleared with WINDOW_CLEAR.

The arithmetic division between the real and logical dimensions must be exact.

WINDOW_SET_TITLE

Changes the title of the window.

output (text) WINDOW_SET_TITLE

Parameters:
- text: new window title

Clear

WINDOW_CLEAR

Clears the window screen.

output (none) WINDOW_CLEAR

Parameters:
- none: no parameters

The clear color is specified with WINDOW_SET_CLEAR_COLOR_NAME or WINDOW_SET_CLEAR_COLOR_RGB.

The default color is black.

License

pico-Céu is distributed under the MIT license reproduced below:

 Copyright (C) 2012-2017 Francisco Sant'Anna

 Permission is hereby granted, free of charge, to any person obtaining a copy of
 this software and associated documentation files (the "Software"), to deal in
 the Software without restriction, including without limitation the rights to
 use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
 of the Software, and to permit persons to whom the Software is furnished to do
 so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.

Files

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pico-ceu-v0.40.md

File metadata and controls

Introduction

Introduction

Resources

Resources

Data Types

Data Types

Color

Point

Rect

Graphics

Graphics

Configuration

GRAPHICS_SET_ANCHOR

GRAPHICS_SET_BMP_FRAME

GRAPHICS_SET_BMP_SIZE

GRAPHICS_SET_COLOR_NAME

GRAPHICS_SET_COLOR_RGB

GRAPHICS_SET_FONT

GRAPHICS_SET_SCALE

GRAPHICS_SET_WRITE_CURSOR

Drawing

GRAPHICS_DRAW_BMP

GRAPHICS_DRAW_PIXEL

GRAPHICS_DRAW_LINE

GRAPHICS_DRAW_RECT

GRAPHICS_DRAW_TEXT

GRAPHICS_DRAW_INT

GRAPHICS_DRAW_REAL

Writing

GRAPHICS_WRITE

GRAPHICS_WRITELN

Other

GRAPHICS_SCREENSHOT

Input Devices

Input Devices

Keyboard

KEY_PRESS

KEY_UNPRESS

Mouse

MOUSE_CLICK

MOUSE_UNCLICK

MOUSE_MOVE

Sound

Sound

Configuration

SOUND_SET_VOLUME

Playback

SOUND_PLAY

Network

Network

Send

NET_SEND

Receive

NET_RECEIVE

Usart

Usart

Includes

Initiate

Send

Usart_TX

Receive

Usart_RX

Frame Management

Frame Management

Configuration

FRAMES_SET

Inputs

FRAMES_UPDATE

FRAMES_REDRAW

Window Management

Window Management

Configuration

WINDOW_SET_CLEAR_COLOR_NAME

WINDOW_SET_CLEAR_COLOR_RGB