1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
/****************************************************************************
**
** 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;
}
"
}
|
