dagon.graphics.filters.blur source code

1 /*
2 Copyright (c) 2017-2018 Timur Gafarov
3 
4 Boost Software License - Version 1.0 - August 17th, 2003
5 Permission is hereby granted, free of charge, to any person or organization
6 obtaining a copy of the software and accompanying documentation covered by
7 this license (the "Software") to use, reproduce, display, distribute,
8 execute, and transmit the Software, and to prepare derivative works of the
9 Software, and to permit third-parties to whom the Software is furnished to
10 do so, all subject to the following:
11 
12 The copyright notices in the Software and this entire statement, including
13 the above license grant, this restriction and the following disclaimer,
14 must be included in all copies of the Software, in whole or in part, and
15 all derivative works of the Software, unless such copies or derivative
16 works are solely in the form of machine-executable object code generated by
17 a source language processor.
18 
19 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
22 SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
23 FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
24 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
25 DEALINGS IN THE SOFTWARE.
26 */
27 
28 module dagon.graphics.filters.blur;
29 
30 import derelict.opengl;
31 import dlib.math.vector;
32 import dagon.core.ownership;
33 import dagon.graphics.postproc;
34 import dagon.graphics.framebuffer;
35 import dagon.graphics.rc;
36 
37 /*
38  * Gaussian blur implementation is based on code by Matt DesLauriers:
39  * https://github.com/Jam3/glsl-fast-gaussian-blur
40  */
41 
42 class PostFilterBlur: PostFilter
43 {
44     private string vs = q{
45         #version 330 core
46         
47         uniform mat4 modelViewMatrix;
48         uniform mat4 projectionMatrix;
49 
50         uniform vec2 viewSize;
51         
52         layout (location = 0) in vec2 va_Vertex;
53         layout (location = 1) in vec2 va_Texcoord;
54 
55         out vec2 texCoord;
56         
57         void main()
58         {
59             texCoord = va_Texcoord;
60             gl_Position = projectionMatrix * modelViewMatrix * vec4(va_Vertex * viewSize, 0.0, 1.0);
61         }
62     };
63 
64     private string fs = q{
65         #version 330 core
66         
67         uniform bool enabled;
68         
69         uniform sampler2D fbColor;
70         uniform vec2 viewSize;
71         uniform vec2 direction;
72         
73         in vec2 texCoord;
74         out vec4 frag_color;
75         
76         vec4 blur9(sampler2D image, vec2 uv, vec2 resolution, vec2 direction)
77         {
78             vec4 color = vec4(0.0);
79             vec2 off1 = vec2(1.3846153846) * direction;
80             vec2 off2 = vec2(3.2307692308) * direction;
81             color += texture2D(image, uv) * 0.2270270270;
82             color += texture2D(image, uv + (off1 / resolution)) * 0.3162162162;
83             color += texture2D(image, uv - (off1 / resolution)) * 0.3162162162;
84             color += texture2D(image, uv + (off2 / resolution)) * 0.0702702703;
85             color += texture2D(image, uv - (off2 / resolution)) * 0.0702702703;
86             return color;
87         }
88         
89         const float weight[5] = float[](0.227027, 0.1945946, 0.1216216, 0.054054, 0.016216);
90 
91         void main()
92         {
93             vec2 fragCoord = gl_FragCoord.xy;
94             vec2 invScreenSize = 1.0 / viewSize;
95 
96             vec3 color;
97             if (enabled)
98             {
99                 color = blur9(fbColor, texCoord, viewSize, direction).rgb;            
100             }
101             else
102             {                
103                 color = vec3(0.0, 0.0, 0.0);
104             }
105             
106             color = clamp(color, vec3(0.0), vec3(1.0));
107         
108             frag_color = vec4(color, 1.0); 
109         }
110     };
111 
112     override string vertexShader()
113     {
114         return vs;
115     }
116 
117     override string fragmentShader()
118     {
119         return fs;
120     }
121     
122     GLint directionLoc;
123     
124     Vector2f direction;
125     float radius = 1.0f; 
126 
127     this(bool horizontal, Framebuffer inputBuffer, Framebuffer outputBuffer, Owner o)
128     {
129         super(inputBuffer, outputBuffer, o);
130         
131         directionLoc = glGetUniformLocation(shaderProgram, "direction");
132         
133         if (horizontal)
134             direction = Vector2f(1.0f, 0.0f);
135         else
136             direction = Vector2f(0.0f, 1.0f);
137     }
138     
139     override void bind(RenderingContext* rc)
140     {
141         super.bind(rc);
142         
143         Vector2f dirScaled = direction * radius;
144         glUniform2fv(directionLoc, 1, dirScaled.arrayof.ptr);
145     }
146 }