import { Shader } from '../shader/Shader';
import { Program } from '../shader/Program';
import { UniformGroup } from '../shader/UniformGroup';
import { Matrix } from '@pixi/math';
/**
* Helper that generates batching multi-texture shader. Use it with your new BatchRenderer
*
* @class
* @memberof PIXI
*/
export class BatchShaderGenerator
{
public vertexSrc: string;
public fragTemplate: string;
programCache: {[key: number]: Program};
defaultGroupCache: {[key: number]: UniformGroup};
/**
* @param {string} vertexSrc - Vertex shader
* @param {string} fragTemplate - Fragment shader template
*/
constructor(vertexSrc: string, fragTemplate: string)
{
/**
* Reference to the vertex shader source.
*
* @member {string}
*/
this.vertexSrc = vertexSrc;
/**
* Reference to the fragement shader template. Must contain "%count%" and "%forloop%".
*
* @member {string}
*/
this.fragTemplate = fragTemplate;
this.programCache = {};
this.defaultGroupCache = {};
if (fragTemplate.indexOf('%count%') < 0)
{
throw new Error('Fragment template must contain "%count%".');
}
if (fragTemplate.indexOf('%forloop%') < 0)
{
throw new Error('Fragment template must contain "%forloop%".');
}
}
generateShader(maxTextures: number): Shader
{
if (!this.programCache[maxTextures])
{
const sampleValues = new Int32Array(maxTextures);
for (let i = 0; i < maxTextures; i++)
{
sampleValues[i] = i;
}
this.defaultGroupCache[maxTextures] = UniformGroup.from({ uSamplers: sampleValues }, true);
let fragmentSrc = this.fragTemplate;
fragmentSrc = fragmentSrc.replace(/%count%/gi, `${maxTextures}`);
fragmentSrc = fragmentSrc.replace(/%forloop%/gi, this.generateSampleSrc(maxTextures));
this.programCache[maxTextures] = new Program(this.vertexSrc, fragmentSrc);
}
const uniforms = {
tint: new Float32Array([1, 1, 1, 1]),
translationMatrix: new Matrix(),
default: this.defaultGroupCache[maxTextures],
};
return new Shader(this.programCache[maxTextures], uniforms);
}
generateSampleSrc(maxTextures: number): string
{
let src = '';
src += '\n';
src += '\n';
for (let i = 0; i < maxTextures; i++)
{
if (i > 0)
{
src += '\nelse ';
}
if (i < maxTextures - 1)
{
src += `if(vTextureId < ${i}.5)`;
}
src += '\n{';
src += `\n\tcolor = texture2D(uSamplers[${i}], vTextureCoord);`;
src += '\n}';
}
src += '\n';
src += '\n';
return src;
}
}