3 This file is part of libmspgl
4 Copyright © 2010 Mikko Rasa, Mikkosoft Productions
5 Distributed under the LGPL
9 #include "ambientocclusion.h"
11 #include "meshbuilder.h"
16 const char vertex_shader[] =
17 "varying vec2 texcoord;\n"
20 " gl_Position = gl_Vertex;\n"
21 " texcoord = gl_Vertex.xy*0.5+0.5;\n"
24 const char occlude_fs[] =
25 "uniform sampler2D depth;\n"
26 "uniform sampler2D rotate;\n"
27 "uniform vec2 screen_size;\n"
28 "uniform vec2 depth_ratio;\n"
29 "uniform float darkness;\n"
30 "varying vec2 texcoord;\n"
33 " mat2 transform = mat2(texture2D(rotate, texcoord*screen_size/4.0)*2.0-1.0)\n"
34 " *mat2(screen_size.y/screen_size.x, 0.0, 0.0, 1.0)*3.0/screen_size.y;\n"
35 " float sample = depth_ratio.x/(texture2D(depth, texcoord).r-depth_ratio.y);\n"
37 " for(int i=0; i<=3; ++i)\n"
38 " for(int j=0; j<=3; ++j)\n"
40 " vec2 offs = transform*vec2(float(i)-1.5, float(j)-1.5);\n"
41 " float dxy = length(offs)*-sample;\n"
42 " float dz = depth_ratio.x/(texture2D(depth, texcoord+offs).r-depth_ratio.y)-sample;\n"
43 " if(abs(dz)<3*dxy)\n"
44 " sum += atan(dz/dxy)/1.570796;\n"
48 " gl_FragColor = vec4(min(1.0-sum*darkness/16.0, 1.0), 0.0, 0.0, 1.0);\n"
51 const char combine_fs[] =
52 "uniform sampler2D color;\n"
53 "uniform sampler2D depth;\n"
54 "uniform sampler2D occlusion;\n"
55 "uniform vec2 screen_size;\n"
56 "uniform vec2 depth_ratio;\n"
57 "varying vec2 texcoord;\n"
60 " float sample = depth_ratio.x/(texture2D(depth, texcoord).r-depth_ratio.y);\n"
62 " float count = 1.0;\n"
63 " for(int i=0; i<=3; ++i)\n"
64 " for(int j=0; j<=3; ++j)\n"
66 " vec2 offs = vec2(float(i)-1.5, float(j)-1.5)/screen_size;\n"
67 " float dxy = length(offs)*-sample;\n"
68 " float dz = depth_ratio.x/(texture2D(depth, texcoord+offs).r-depth_ratio.y)-sample;\n"
69 " if(abs(dz)<3*dxy)\n"
71 " sum += texture2D(occlusion, texcoord+offs).r;\n"
75 " gl_FragColor = texture2D(color, texcoord)*sum/count;\n"
83 AmbientOcclusion::AmbientOcclusion(unsigned w, unsigned h, float depth_ratio):
84 occlude_shader(vertex_shader, occlude_fs),
85 combine_shader(vertex_shader, combine_fs),
88 occlusion.storage(GL::RGB, w, h);
89 occlusion.set_min_filter(GL::NEAREST);
90 occlusion.set_mag_filter(GL::NEAREST);
91 fbo.attach(COLOR_ATTACHMENT0, occlusion, 0);
93 combine_texturing.attach(2, occlusion);
95 rotate_lookup.storage(GL::RGBA, 4, 4);
96 rotate_lookup.set_min_filter(GL::NEAREST);
97 rotate_lookup.set_mag_filter(GL::NEAREST);
98 unsigned char data[64];
99 for(unsigned i=0; i<16; ++i)
101 float a = ((i*541)%16)*M_PI/32;
104 data[i*3 ] = static_cast<unsigned char>(127+c*127);
105 data[i*3+1] = static_cast<unsigned char>(127+s*127);
106 data[i*3+2] = static_cast<unsigned char>(127-s*127);
107 data[i*3+4] = static_cast<unsigned char>(127+c*127);
109 rotate_lookup.image(0, GL::RGBA, GL::UNSIGNED_BYTE, data);
111 occlude_texturing.attach(1, rotate_lookup);
113 occlude_shdata.uniform(occlude_shader.get_uniform_location("depth"), 0);
114 occlude_shdata.uniform(occlude_shader.get_uniform_location("rotate"), 1);
115 occlude_shdata.uniform(occlude_shader.get_uniform_location("screen_size"), w, h);
117 combine_shdata.uniform(combine_shader.get_uniform_location("color"), 1);
118 combine_shdata.uniform(combine_shader.get_uniform_location("depth"), 0);
119 combine_shdata.uniform(combine_shader.get_uniform_location("occlusion"), 2);
120 combine_shdata.uniform(combine_shader.get_uniform_location("screen_size"), w, h);
122 set_depth_ratio(depth_ratio);
125 MeshBuilder bld(quad);
126 bld.begin(TRIANGLE_STRIP);
134 void AmbientOcclusion::set_depth_ratio(float depth_ratio)
136 depth_ratio = 1/depth_ratio;
138 occlude_shdata.uniform(occlude_shader.get_uniform_location("depth_ratio"), depth_ratio, 1+depth_ratio);
139 combine_shdata.uniform(combine_shader.get_uniform_location("depth_ratio"), depth_ratio, 1+depth_ratio);
142 void AmbientOcclusion::set_darkness(float darkness)
144 occlude_shdata.uniform(occlude_shader.get_uniform_location("darkness"), darkness);
147 void AmbientOcclusion::render(const Texture2D &color, const Texture2D &depth)
149 occlude_texturing.attach(0, depth);
150 combine_texturing.attach(0, depth);
151 combine_texturing.attach(1, color);
153 Bind unbind_dtest(static_cast<DepthTest *>(0), true);
154 Bind unbind_blend(static_cast<Blend *>(0), true);
157 GL::Bind bind_fbo(fbo, true);
158 GL::Bind bind_tex(occlude_texturing);
159 GL::Bind bind_shader(occlude_shader);
160 occlude_shdata.apply();
164 GL::Bind bind_tex(combine_texturing);
165 GL::Bind bind_shader(combine_shader);
166 combine_shdata.apply();