/**************************************************************************** ** ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). ** All rights reserved. ** Contact: Nokia Corporation (qt-info@nokia.com) ** ** This file is part of the QML Shaders plugin of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:LGPL$ ** No Commercial Usage ** This file contains pre-release code and may not be distributed. ** You may use this file in accordance with the terms and conditions ** contained in the Technology Preview License Agreement accompanying ** this package. ** ** GNU Lesser General Public License Usage ** Alternatively, this file may be used under the terms of the GNU Lesser ** General Public License version 2.1 as published by the Free Software ** Foundation and appearing in the file LICENSE.LGPL included in the ** packaging of this file. Please review the following information to ** ensure the GNU Lesser General Public License version 2.1 requirements ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. ** ** In addition, as a special exception, Nokia gives you certain additional ** rights. These rights are described in the Nokia Qt LGPL Exception ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. ** ** If you have questions regarding the use of this file, please contact ** Nokia at qt-info@nokia.com. ** ** ** ** ** ** ** ** ** $QT_END_LICENSE$ ** ****************************************************************************/ import QtQuick 1.0 import Qt.labs.shaders 1.0 // Note 1. This shader implements gaussian blur without dynamic array access from inside shader loops (Optional feature in OpenGLES 2.0). // Note 2. Shader code is generated to avoid ecessive if-else structure in fragment shader. Code re-generation (very slow!) happens if blur radius is changed. ShaderEffectItem { id: effect property variant source: 0 property real deviation: Math.sqrt(-((radius+1) * (radius+1)) / (2 * Math.log(1.0 / 255.0))); property real radius: 8; property real deltaX: 0.0 property real deltaY: 0.0 property real gaussianSum: 0.0 property real startIndex: 0.0 property real samples: radius * 2 property variant gwts: [] property variant delta: Qt.vector3d(effect.deltaX, effect.deltaY, effect.startIndex); property variant factor_0_2: Qt.vector3d(effect.gwts[0], effect.gwts[1], effect.gwts[2]); property variant factor_3_5: Qt.vector3d(effect.gwts[3],effect.gwts[4],effect.gwts[5]); property variant factor_6_8: Qt.vector3d(effect.gwts[6],effect.gwts[7],effect.gwts[8]); property variant factor_9_11: Qt.vector3d(effect.gwts[9],effect.gwts[10],effect.gwts[11]); property variant factor_12_14: Qt.vector3d(effect.gwts[12],effect.gwts[13],effect.gwts[14]); property variant factor_15_17: Qt.vector3d(effect.gwts[15],effect.gwts[16],effect.gwts[17]); property variant factor_18_20: Qt.vector3d(effect.gwts[18],effect.gwts[19],effect.gwts[20]); property variant factor_21_23: Qt.vector3d(effect.gwts[21],effect.gwts[22],effect.gwts[23]); property variant factor_24_26: Qt.vector3d(effect.gwts[24],effect.gwts[25],effect.gwts[26]); property variant factor_27_29: Qt.vector3d(effect.gwts[27],effect.gwts[28],effect.gwts[29]); property variant factor_30_32: Qt.vector3d(effect.gwts[30],effect.gwts[31],effect.gwts[32]); //Gaussian function = h(x):=(1/sqrt(2*3.14159*(D^2))) * %e^(-(x^2)/(2*(D^2))); function gausFunc(x){ return (1/Math.sqrt(2*3.1415926*(Math.pow(effect.deviation,2)))) * Math.pow(2.7182818,-((Math.pow(x,2))/(2*(Math.pow(effect.deviation,2))))); } function calcGWTS() { var n = new Array(Math.floor(effect.samples)); var step for (var i = 0; i < effect.samples; i++) { step = -effect.samples/2 + i + 0.5 n[i] = gausFunc(step); } return n; } function buildFragmentShader() { var shaderSteps = [ "gl_FragColor += texture2D(source, texCoord) * factor_0_2.x; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_0_2.y; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_0_2.z; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_3_5.x; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_3_5.y; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_3_5.z; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_6_8.x; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_6_8.y; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_6_8.z; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_9_11.x; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_9_11.y; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_9_11.z; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_12_14.x; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_12_14.y; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_12_14.z; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_15_17.x; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_15_17.y; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_15_17.z; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_18_20.x; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_18_20.y; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_18_20.z; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_21_23.x; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_21_23.y; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_21_23.z; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_24_26.x; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_24_26.y; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_24_26.z; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_27_29.x; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_27_29.y; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_27_29.z; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_30_32.x; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_30_32.y; texCoord += shift;", "gl_FragColor += texture2D(source, texCoord) * factor_30_32.z; texCoord += shift;" ] var shader = fragmentShader_begin var samples = effect.samples if (samples > 32) { console.log("GaussianBlur: Maximum of 32 blur samples exceeded!") samples = 32 } for (var i = 0; i < samples; i++) { shader += shaderSteps[i] } shader += fragmentShader_end effect.fragmentShader = shader } onDeviationChanged:{ effect.startIndex = -effect.samples/2 + 0.5 effect.gwts = calcGWTS(); var sum = 0.0; for (var j = 0; j < effect.samples; j++) { sum += effect.gwts[j]; } effect.gaussianSum = sum } Component.onCompleted:{ effect.startIndex = -effect.samples/2 + 0.5 effect.gwts = calcGWTS(); var sum = 0.0; for (var j = 0; j < effect.samples; j++) { sum += effect.gwts[j]; } effect.gaussianSum = sum buildFragmentShader() } onSamplesChanged: { buildFragmentShader() } property string fragmentShader_begin: " varying mediump vec2 qt_TexCoord0; uniform sampler2D source; uniform highp vec3 delta; uniform highp vec3 factor_0_2; uniform highp vec3 factor_3_5; uniform highp vec3 factor_6_8; uniform highp vec3 factor_9_11; uniform highp vec3 factor_12_14; uniform highp vec3 factor_15_17; uniform highp vec3 factor_18_20; uniform highp vec3 factor_21_23; uniform highp vec3 factor_24_26; uniform highp vec3 factor_27_29; uniform highp vec3 factor_30_32; uniform highp float gaussianSum; void main() { highp vec2 shift = vec2(delta.x, delta.y); highp float index = delta.z; mediump vec2 texCoord = qt_TexCoord0 + (shift * index); gl_FragColor = vec4(0.0, 0.0, 0.0, 0.0); " property string fragmentShader_end: " if (gaussianSum > 0.0) gl_FragColor /= gaussianSum; } " }