catgl

Catgl is a cross-platform 3D graphics engine intended to be easy-to-use and high performance, which also supports the features for game development, such as animation, input device handling and sound playing. This application is designed for Android, iOS, Linux, Windows.

Technologies

OpenGL / OpenGLES
GLSL (OpenGL Shading Language)
NanoVG (https://github.com/memononen/nanovg)
stb single-file public domain libraries (https://github.com/nothings/stb)
GLFW (for Linux)
Android NDK (for Android)

Install

for Linux
- dnf install glfw-devel
for Android
- Download android-sdk-linux and install it.
  - tools/android update sdk
    - Android SDK Tools
    - Android SDK Platform-tools
    - Android SDK Build-tools
    - API 10 SDK Platform
    - Android Support Library
- Download android-ndk
- dnf install ant

Examples

Linux

$ cd sample/box
$ make

Android

$ cd sample/box
$ make android

How to use

Skeleton

#define CATGL_IMPLEMENTATION
#include "catgl.h"

void caInit(int width, int height)
{
}

void caRender()
{
}

void caEnd()
{
}

$ clang -std=c11 -Os -MMD -MP -Wall -Wextra -Winit-self -Wno-unused-parameter -Wno-float-equal -Wno-missing-braces -I../../ -I../../nanovg -o obj/main.o -c main.c
$ clang++ -o hello obj/main.o /lib/libglfw.so /lib/libGL.so /lib/libm.so

Eyes

#define CATGL_NANOVG
#define CATGL_IMPLEMENTATION
#include "catgl.h"

struct NVGcontext* vg;
int width, height;
float pixelRatio;

int c_action, c_x, c_y;
void mouseEvent(int button, int action, int x, int y)
{
	c_action = action;
	c_x = x;
	c_y = y;
}

void caInit(int w, int h)
{
	width = w;
	height = h;
	pixelRatio = (float)width / (float)height;

	caMouseEvent = mouseEvent;

	nvgCreateEx(vg, NVG_ANTIALIAS);
}

void caRender()
{
	glViewport(0, 0, width, height);

	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
	glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT|GL_STENCIL_BUFFER_BIT);

	glEnable(GL_BLEND);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
	glEnable(GL_CULL_FACE);
	glDisable(GL_DEPTH_TEST);

	nvgBeginFrame(vg, width, height, pixelRatio);
	static int c;
	caDrawEyes(vg, 320, 180, 640, 360, c_x, c_y, c/10);
	c++;
	nvgEndFrame(vg);
}

void caEnd()
{
	nvgDelete(vg);
}