SimpleShader helper class

SimpleShader helper class
0

SimpleShader

This is a simple utility for creating shaders inside of Cocos2dx
targeted towards people new to the engine,
it simplifies the creation and usage of fragment shaders.

Github Repo

Usage

//create new shader with default vertex shader
auto shader = SimpleShader::createWithFragmentShader("shaders/simple.fsh");

//set float uniform
shader->setUniform("opacity", 0.5f);

//set texture uniform (SimpleShader will manage the texture slots for you)
auto tex = Director::getInstance()->getTextureCache()->addImage("textures/tex.png");
shader->setUniform("someTexture", tex);

//apply shader to a sprite 
sprite->setProgramState(shader->programState);

Simpler Fragment Shaders

SimpleShader makes creating custom fragment shaders easier by eliminating boilerplate code,
all you need to do is define your custom uniforms and main function

uniform sampler2D someTexture;
uniform float opacity;

void main()
{
    //u_texture is the sprites original texture
    vec4 spritesTexture = texture2D(u_texture, cc_FragTexCoord1);

    //the texture we passed as a uniform
    vec4 tex = texture2D(someTexture, cc_FragTexCoord1);

    gl_FragColor = mix(spritesTexture, tex, opacity);
}

Example Shader

SimpleShader automatically injects these uniforms into your shaders

//the texture of the sprite the shader is applied to 
u_texture

//the texture coordinates
cc_FragTexCoord1

//the color of the sprite the shader is applied to
cc_FragColor

//the current time in seconds 
cc_Time

Time Based Effects

by default SimpleShader adds a cc_Time uniform to all fragment shaders for easily creating time based effects,

to update the time uniform for all shaders simply call the updateShaderTime method on the SimpleShaderManager object in your scenes update method

//call scheduleUpdate() in your scenes init method to enable update callbacks
virtual void update(float delta)
{
    SimpleShaderManager::getInstance()->updateShaderTime();
}
2 Likes

Could you show me some pictures to visualize it ? On github, I don’t see the test images ,shader ex : shaders/simple.fsh,textures/tex.png …v…v…

Hey, sure, I added an example project to github