glreduction.cpp 6.68 KB
Newer Older
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
// ================================================================================================
// 
// This file is part of the CAMPVis Software Framework.
// 
// If not explicitly stated otherwise: Copyright (C) 2012, all rights reserved,
//      Christian Schulte zu Berge <christian.szb@in.tum.de>
//      Chair for Computer Aided Medical Procedures
//      Technische Universität München
//      Boltzmannstr. 3, 85748 Garching b. München, Germany
// For a full list of authors and contributors, please refer to the file "AUTHORS.txt".
// 
// The licensing of this softare is not yet resolved. Until then, redistribution in source or
// binary forms outside the CAMP chair is not permitted, unless explicitly stated in legal form.
// However, the names of the original authors and the above copyright notice must retain in its
// original state in any case.
// 
// Legal disclaimer provided by the BSD license:
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
// IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY 
// AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 
// OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
// 
// ================================================================================================

#include "glreduction.h"

#include "tgt/logmanager.h"
#include "tgt/framebufferobject.h"
#include "tgt/shadermanager.h"
#include "tgt/texture.h"
#include "tgt/textureunit.h"

#include "core/datastructures/facegeometry.h"
#include "core/datastructures/imagedata.h"
#include "core/datastructures/imagerepresentationgl.h"
#include "core/tools/quadrenderer.h"

#include <algorithm>

#define DIV_CEIL(x,y) ((x) > 0) ? (1 + ((x) - 1)/(y)) : ((x) / (y))

namespace campvis {

    const std::string GlReduction::loggerCat_ = "CAMPVis.modules.registration.GlReduction";

    GlReduction::GlReduction()
        : _shader(0)
        , _fbo(0)
        , _renderQuad(0)
    {
        _shader = ShdrMgr.loadSeparate("core/glsl/passthrough.vert", "core/glsl/glsl/glreduction.frag", "", false);
        if (_shader == 0) {
            LERROR("Could not load Shader for OpenGL reduction. Reduction will not work!");
            return;
        }

        _shader->setAttributeLocation(0, "in_Position");
        _shader->setAttributeLocation(1, "in_TexCoord");
    }

    GlReduction::~GlReduction() {

    }

    float GlReduction::reduce(const ImageData* image) {
        tgtAssert(image != 0, "Image must not be 0!");
        if (_shader == 0) {
            LERROR("Could not load Shader for OpenGL reduction. Reduction will not work!");
            return 0.f;
        }
        if (image == 0) {
            LERROR("Empty image received - nothing to reduce!");
            return 0.f;
        }

        const ImageRepresentationGL* repGl = image->getRepresentation<ImageRepresentationGL>();
        if (repGl == 0) {
            LERROR("Could not convert input image to OpenGL texture - no reduction possible!");
            return 0.f;
        }

        tgtAssert(image->getNumChannels() == 1, "Reduction of images with more than one channel currently not implemented! Somebody was too lazy (or stressed - deadline was close) to do that...");

        const tgt::svec3& size = image->getSize();
        tgt::vec2 texCoordMultiplier(1.f);
        tgt::ivec2 currentSize = size.xy();
        reduceSizes(currentSize, texCoordMultiplier);

        // Set OpenGL pixel alignment to 1 to avoid problems with NPOT textures
        glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

        // get a free texture unit
        tgt::TextureUnit inputUnit;

        // create temporary textures
        for (size_t i = 0; i < 2; ++i) {
            _tempTextures[i] = new tgt::Texture(0, tgt::ivec3(currentSize, 1), GL_RED, GL_R32F, GL_FLOAT, tgt::Texture::NEAREST);
            //_tempTextures[i] = new tgt::Texture(0, tgt::ivec3(currentSize, 1), GL_RGBA, GL_RGBA8, GL_FLOAT, tgt::Texture::NEAREST);
            _tempTextures[i]->uploadTexture();
            _tempTextures[i]->setWrapping(tgt::Texture::CLAMP);
        }
        _readTex = 0;
        _writeTex = 1;

        // create and initialize FBO
        _fbo = new tgt::FramebufferObject();
        _fbo->activate();
        LGL_ERROR;

        // perform first reduction step outside:
        _shader->activate();
        repGl->bind(_shader, inputUnit);
        _fbo->attachTexture(_tempTextures[_readTex]);

        glViewport(0, 0, currentSize.x, currentSize.y);
        _shader->setUniform("_texCoordsMultiplier", texCoordMultiplier);
        QuadRdr.renderQuad();
        LGL_ERROR;

        // perform reduction until 1x1 texture remains
        while (currentSize.x > 1 || currentSize.y > 1) {
            reduceSizes(currentSize, texCoordMultiplier);

            _fbo->attachTexture(_tempTextures[_writeTex]);
            _tempTextures[_readTex]->bind();

            glViewport(0, 0, currentSize.x, currentSize.y);
            _shader->setUniform("_texCoordsMultiplier", texCoordMultiplier);
            QuadRdr.renderQuad();
            LGL_ERROR;

            //_fbo->detachTexture(GL_COLOR_ATTACHMENT0);
            std::swap(_writeTex, _readTex);
        }

        _shader->deactivate();


        // read back stuff
        GLenum readBackFormat = _tempTextures[_readTex]->getFormat();
        size_t channels = _tempTextures[_readTex]->getNumChannels();

        std::vector<float> readBackBuffer;
        readBackBuffer.resize(currentSize.x * currentSize.y * channels);
        glReadBuffer(GL_COLOR_ATTACHMENT0);
        glReadPixels(0, 0, currentSize.x, currentSize.y, readBackFormat, GL_FLOAT, &readBackBuffer.front());
        LGL_ERROR;

        // clean up...
        _fbo->detachAll();
        _fbo->deactivate();
        delete _fbo;
        _fbo = 0;

        delete _tempTextures[0];
        delete _tempTextures[1];
        LGL_ERROR;

        return readBackBuffer.front();
    }

    void GlReduction::reduceSizes(tgt::ivec2& currentSize, tgt::vec2& texCoordMultiplier) {
        if (currentSize.x > 1) {
            currentSize.x = DIV_CEIL(currentSize.x, 2);
            texCoordMultiplier.x /= 2.f;
        }
        if (currentSize.y > 1) {
            currentSize.y = DIV_CEIL(currentSize.y, 2);
            texCoordMultiplier.y /= 2.f;
        }
        
    }

}