效果图：
补上有背景时的效果：
代码如下，写的粗糙，有问题还请指出：
public static TRANSFER_VERT:string = `
attribute vec4 a_position;
attribute vec2 a_texCoord;
attribute vec4 a_color;
varying vec4 v_fragmentColor;
varying vec2 v_texCoord;
void main()
{
gl_Position = CC_PMatrix * a_position;
v_fragmentColor = a_color;
v_texCoord = a_texCoord;
}
`;
public static TRANSFER_FRAG:string = `
#ifdef GL_ES
precision lowp float;
#endif
uniform float time;
varying vec4 v_fragmentColor;
varying vec2 v_texCoord;
void main()
{
vec4 c = v_fragmentColor * texture2D(CC_Texture0, v_texCoord);
gl_FragColor = c;
float temp = v_texCoord.x - time;
if (temp <= 0.0) {
float temp2 = abs(temp);
if (temp2 <= 0.2) {
gl_FragColor.w = 1.0 - temp2/0.2;
} else {
gl_FragColor.w = 0.0;
}
} else {
gl_FragColor.w = 1.0;
}
}
`;
private _program:any;
private _time:number = 0;
start () {
this.testShader();
}
testShader() {
let bgSp:cc.Sprite = this.bgNode.getChildByName("bg").getComponent(cc.Sprite);
this._program = new cc.GLProgram();
if (cc.sys.isNative) {
this._program.initWithString(StoryHandlerScript.TRANSFER_VERT, StoryHandlerScript.TRANSFER_FRAG);
} else {
this._program.initWithVertexShaderByteArray(StoryHandlerScript.TRANSFER_VERT, StoryHandlerScript.TRANSFER_FRAG);
this._program.addAttribute(cc.macro.ATTRIBUTE_NAME_POSITION, cc.macro.VERTEX_ATTRIB_POSITION);
this._program.addAttribute(cc.macro.ATTRIBUTE_NAME_COLOR, cc.macro.VERTEX_ATTRIB_COLOR);
this._program.addAttribute(cc.macro.ATTRIBUTE_NAME_TEX_COORD, cc.macro.VERTEX_ATTRIB_TEX_COORDS);
}
this._program.link();
this._program.updateUniforms();
this._program.use();
if (cc.sys.isNative) {
var glProgram_state = cc.GLProgramState.getOrCreateWithGLProgram(this._program);
glProgram_state.setUniformFloat( "time", this._time );
} else {
let time = this._program.getUniformLocationForName("time");
this._program.setUniformLocationWith1f(time, this._time);
}
bgSp._sgNode.setShaderProgram(this._program);
}
update(dt){
this._time += 0.02;
if (this._program) {
this._program.use();
if (cc.sys.isNative) {
var glProgram_state = cc.GLProgramState.getOrCreateWithGLProgram(this._program);
glProgram_state.setUniformFloat( "time", this._time );
} else {
let time = this._program.getUniformLocationForName("time");
this._program.setUniformLocationWith1f(time, this._time);
}
}
}
