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cntools / rawdraw

Primitive Platform Agnostic Graphics Library
MIT License
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CN's Fundamental Graphics Library

An OS-Agnostic (including No OS AT ALL!) drawing system. It includes lines, boxes, linetext, points, bitmaps.

The drawing method can either be by the OS (i.e. SetPixel in Windows), rasterized in software (we draw our own lines) or by OpenGL where available. You can reconfigure it with various #defines. It also makes it really easy to get an OpenGL window on just about any supported platform.

Somewhere unusual and want to open a window and draw stuff? Use rawdraw.

Other packages too big, bulky or include junk you don't want? Use rawdraw.

Want to use OpenGL really quickly? Use rawdraw.

For embedded platforms, CNFGRASTERIZER is usually the back end which allows you to have high level commands on a framebuffer. It's what was used in ESP Channel 3. You can even play with the rasterizer on every mode except the Android port by defining it. You can even be twisted on Windows, Linux and on WASM (Web) and define it.

This is not like SDL - some drivers have different quirks, some have more features implemented than others, and a major goal is not to abstract very much, but almost to provide an exmaple how to use graphics on a specific platform.

Platform statuses

Usage in project

You may want to include CNFG as a submodule or as a single-file header. You can just download rawdraw_sf.h to the path your project is in and #include it.

To use it as a single file (rawdraw_sf.h), you can just wget https://raw.githubusercontent.com/cntools/rawdraw/master/rawdraw_sf.h

To use it as a submodule you can:

git submodule add https://github.com/cntools/rawdraw

paste the command above on your terminal to get a clone of the repository on your system.

note: Incase you get a error saying 

fatal: not a git repository (or any parent up to mount point /)
Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).

use the command git init first.

To use CNFG, be sure to do this, or include "CNFG.c" in your project.

#define CNFG_IMPLEMENTATION

Usage on Linux

Prerequisites

Firstly, make sure you have the necessary packages and libraries installed.

To install on Debian/Ubuntu:

sudo apt-get update
sudo apt-get install xorg-dev libx11-dev libxinerama-dev libxext-dev mesa-common-dev libglu1-mesa-dev

To install on Arch Linux:

sudo pacman -Sy xorg-server-devel libx11 libxinerama libxext mesa glu

Running

To run the sample program in rawdraw:

  1. Clone the repository on your system and run cd rawdraw/.
  2. Run the command make (compiles and creates an executable called "simple" from "simple.c").
  3. Run the command ./simple to execute "simple".

Example program

A more comprehensive example can be found in rawdraw.c, but a basic example is as follows:


//Make it so we don't need to include any other C files in our build.
#define CNFG_IMPLEMENTATION

#include "rawdraw_sf.h"

void HandleKey( int keycode, int bDown ) { }
void HandleButton( int x, int y, int button, int bDown ) { }
void HandleMotion( int x, int y, int mask ) { }
int HandleDestroy() { return 0; }
int main()
{
    CNFGSetup( "Example App", 1024, 768 );
    while(CNFGHandleInput())
    {
        CNFGBGColor = 0x000080ff; //Dark Blue Background

        short w, h;
        CNFGClearFrame();
        CNFGGetDimensions( &w, &h );

        //Change color to white.
        CNFGColor( 0xffffffff ); 

        CNFGPenX = 1; CNFGPenY = 1;
        CNFGDrawText( "Hello, World", 2 );
        //Draw a white pixel at 30, 30 
        CNFGTackPixel( 30, 30 );         

        //Draw a line from 50,50 to 100,50
        CNFGTackSegment( 50, 50, 100, 50 );

        //Dark Red Color Select
        CNFGColor( 0x800000FF ); 

        //Draw 50x50 box starting at 100,50
        CNFGTackRectangle( 100, 50, 150, 100 ); 

        //Bright Purple Select
        CNFGColor( 0x800000FF ); 

        //Draw a triangle
        RDPoint points[3] = { { 30, 36}, {20, 50}, { 40, 50 } };
        CNFGTackPoly( points, 3 );

        //Draw a bunch of random pixels as a blitted image.
        {
            static uint32_t data[64*64];
            int x, y;

            for( y = 0; y < 64; y++ ) for( x = 0; x < 64; x++ )
                data[x+y*64] = 0xff | (rand()<<8);

            CNFGBlitImage( data, 150, 30, 64, 64 );
        }

        //Display the image and wait for time to display next frame.
        CNFGSwapBuffers();      
    }
}

Building

Windows compile: Build with clang

clang simple.c -o simple -Irawdraw -lopengl32 -lgdi32 -luser32

Build with TCC

C:\tcc\tcc simple.c -Irawdraw -lopengl32 -lgdi32 -luser32 C:\windows\system32\msvcrt.dll

Linux compile:

gcc -o simple simple.c -lm -lX11 -lGL

Note, with the STB-style header, you don't need to #define CNFG_IMPLEMENTATION anywhere in your code, and instead can also compile in cnfg.c

Configurations

Rawdraw is a very disjoint set of configurations

CNFG Configuration options include:

Platform-Specific

Flags you will probably never want to use:

Extra goodies

RDUI

RDUI is mainted by Overlisted and contains a lot of extra features for rawdraw. You can check it out here: https://git.overlisted.net/me/rdui/

chew.h

You can copy-and-paste chew.c and chew.h into your program for a single-file compile-only version of GLEW. This is WAY BETTER than having to deal with the complicated system they have set up, but it doesn't include all the functions. You can easily add OpenGL functions to it.

It provides a very easy-to-use interface for OpenGL Extensions.

os_generic.h

os_generic is a platform independent way of creating threads, managing TLS, mutices, semaphores as well as getting the current time. It has the following configuration options:

OSG_NO_IMPLEMENTATION - Do not include implementation as static functions. OSG_PREFIX - Override function prefix OSG_NOSTATIC - Do not declare the functions as static.

TextTool/Text.c etc...

There is a sister repository, https://github.com/cntools/rawdrawtools which houses a text tool.

Warnings