phaser/src/renderer/webgl/Utils.js
2022-09-22 14:55:29 +01:00

171 lines
5.5 KiB
JavaScript

/**
* @author Richard Davey <rich@photonstorm.com>
* @author Felipe Alfonso <@bitnenfer>
* @author Matthew Groves <@doormat>
* @copyright 2022 Photon Storm Ltd.
* @license {@link https://opensource.org/licenses/MIT|MIT License}
*/
/**
* @namespace Phaser.Renderer.WebGL.Utils
* @since 3.0.0
*/
module.exports = {
/**
* Packs four floats on a range from 0.0 to 1.0 into a single Uint32
*
* @function Phaser.Renderer.WebGL.Utils.getTintFromFloats
* @since 3.0.0
*
* @param {number} r - Red component in a range from 0.0 to 1.0
* @param {number} g - Green component in a range from 0.0 to 1.0
* @param {number} b - Blue component in a range from 0.0 to 1.0
* @param {number} a - Alpha component in a range from 0.0 to 1.0
*
* @return {number} The packed RGBA values as a Uint32.
*/
getTintFromFloats: function (r, g, b, a)
{
var ur = ((r * 255) | 0) & 0xff;
var ug = ((g * 255) | 0) & 0xff;
var ub = ((b * 255) | 0) & 0xff;
var ua = ((a * 255) | 0) & 0xff;
return ((ua << 24) | (ur << 16) | (ug << 8) | ub) >>> 0;
},
/**
* Packs a Uint24, representing RGB components, with a Float32, representing
* the alpha component, with a range between 0.0 and 1.0 and return a Uint32
*
* @function Phaser.Renderer.WebGL.Utils.getTintAppendFloatAlpha
* @since 3.0.0
*
* @param {number} rgb - Uint24 representing RGB components
* @param {number} a - Float32 representing Alpha component
*
* @return {number} Packed RGBA as Uint32
*/
getTintAppendFloatAlpha: function (rgb, a)
{
var ua = ((a * 255) | 0) & 0xff;
return ((ua << 24) | rgb) >>> 0;
},
/**
* Packs a Uint24, representing RGB components, with a Float32, representing
* the alpha component, with a range between 0.0 and 1.0 and return a
* swizzled Uint32
*
* @function Phaser.Renderer.WebGL.Utils.getTintAppendFloatAlphaAndSwap
* @since 3.0.0
*
* @param {number} rgb - Uint24 representing RGB components
* @param {number} a - Float32 representing Alpha component
*
* @return {number} Packed RGBA as Uint32
*/
getTintAppendFloatAlphaAndSwap: function (rgb, a)
{
var ur = ((rgb >> 16) | 0) & 0xff;
var ug = ((rgb >> 8) | 0) & 0xff;
var ub = (rgb | 0) & 0xff;
var ua = ((a * 255) | 0) & 0xff;
return ((ua << 24) | (ub << 16) | (ug << 8) | ur) >>> 0;
},
/**
* Unpacks a Uint24 RGB into an array of floats of ranges of 0.0 and 1.0
*
* @function Phaser.Renderer.WebGL.Utils.getFloatsFromUintRGB
* @since 3.0.0
*
* @param {number} rgb - RGB packed as a Uint24
*
* @return {array} Array of floats representing each component as a float
*/
getFloatsFromUintRGB: function (rgb)
{
var ur = ((rgb >> 16) | 0) & 0xff;
var ug = ((rgb >> 8) | 0) & 0xff;
var ub = (rgb | 0) & 0xff;
return [ ur / 255, ug / 255, ub / 255 ];
},
/**
* Check to see how many texture units the GPU supports in a fragment shader
* and if the value specific in the game config is allowed.
*
* This value is hard-clamped to 16 for performance reasons on Android devices.
*
* @function Phaser.Renderer.WebGL.Utils.checkShaderMax
* @since 3.50.0
*
* @param {WebGLRenderingContext} gl - The WebGLContext used to create the shaders.
* @param {number} maxTextures - The Game Config maxTextures value.
*
* @return {number} The number of texture units that is supported by this browser and GPU.
*/
checkShaderMax: function (gl, maxTextures)
{
// Note: This is the maximum number of TIUs that a _fragment_ shader supports
// https://www.khronos.org/opengl/wiki/Common_Mistakes#Texture_Unit
// Hard-clamp this to 16 to avoid run-away texture counts such as on Android
var gpuMax = Math.min(16, gl.getParameter(gl.MAX_TEXTURE_IMAGE_UNITS));
if (!maxTextures || maxTextures === -1)
{
return gpuMax;
}
else
{
return Math.min(gpuMax, maxTextures);
}
},
/**
* Checks the given Fragment Shader Source for `%count%` and `%getSampler%` declarations and
* replaces those with GLSL code for setting `texture = texture2D(uMainSampler[i], outTexCoord)`
* and injecting the `getSampler` glsl function.
*
* @function Phaser.Renderer.WebGL.Utils.parseFragmentShaderMaxTextures
* @since 3.50.0
*
* @param {string} fragmentShaderSource - The Fragment Shader source code to operate on.
* @param {number} maxTextures - The number of maxTextures value.
*
* @return {string} The modified Fragment Shader source.
*/
parseFragmentShaderMaxTextures: function (fragmentShaderSource, maxTextures)
{
if (!fragmentShaderSource)
{
return '';
}
/*
var src = 'vec4 getSampler (int index, vec2 uv) {';
for (var i = 0; i < maxTextures; i++)
{
if (i > 0 && i < maxTextures)
{
src += '\nelse ';
}
src += 'if (index == ' + i + ') { return texture2D(uMainSampler[' + i + '], uv); }';
}
src += '\nreturn vec4(0);\n}';
fragmentShaderSource = fragmentShaderSource.replace(/%getSampler%/gi, src);
*/
return fragmentShaderSource.replace(/%count%/gi, maxTextures.toString());
}
};