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.
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);
}
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();
}