texture3d.frag 4.59 KB
Newer Older
1 2
// ================================================================================================
// 
schultezub's avatar
schultezub committed
3
// This file is part of the CAMPVis Software Framework.
4 5
// 
// If not explicitly stated otherwise: Copyright (C) 2012, all rights reserved,
schultezub's avatar
schultezub committed
6
//      Christian Schulte zu Berge <christian.szb@in.tum.de>
7 8 9
//      Chair for Computer Aided Medical Procedures
//      Technische Universität München
//      Boltzmannstr. 3, 85748 Garching b. München, Germany
schultezub's avatar
schultezub committed
10
// For a full list of authors and contributors, please refer to the file "AUTHORS.txt".
11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
// 
// 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.
// 
// ================================================================================================

schultezub's avatar
schultezub committed
30 31
// TODO: implement coordinate transformation using a trafo matrix?

32
struct TextureParameters3D {
schultezub's avatar
schultezub committed
33 34 35
    // Texture size
    vec3 _size;
    vec3 _sizeRCP;
36

37 38 39
    // Number of channels
    int _numChannels;

40 41 42
    // Voxel spacing
    vec3 _voxelSize;
    vec3 _voxelSizeRCP;
43 44 45

    // Transformation matrices
    mat4 _textureToWorldMatrix;
46
    mat4 _worldToTextureMatrix;
47 48

    vec2 _realWorldMapping;
schultezub's avatar
schultezub committed
49 50 51
};

/**
schultezub's avatar
schultezub committed
52
 * Texture lookup function for 3D textures using voxel coordinates, i.e [(0,0) , textureSize].
53 54
 * \param	tex			Sampler to texture
 * \param	texParams   TextureParameters3D struct with texture for lookup
schultezub's avatar
schultezub committed
55 56 57
 * \param	texCoords	Lookup coordinates in pixel coordinates
 * \return	The texel at the given coordinates.
 */
58 59
vec4 getElement3D(in sampler3D tex, in TextureParameters3D texParams, in vec3 texCoords) {
    vec3 texCoordsNormalized = texCoords * texParams._sizeRCP;
schultezub's avatar
schultezub committed
60
    //vec2 texCoordsTransformed = (texParams.matrix_ * vec4(texCoordsNormalized, 0.0, 1.0)).xy;
61
    return texture(tex, texCoordsNormalized);
schultezub's avatar
schultezub committed
62 63 64 65
}

/**
 * Texture lookup function for 3D textures using normalized texture coordinates, i.e. [0,1].
66 67
 * \param	tex			Sampler to texture
 * \param	texParams   TextureParameters3D struct with texture for lookup
schultezub's avatar
schultezub committed
68 69 70
 * \param	texCoords	Lookup coordinates in normlized texture coordinates
 * \return	The texel at the given coordinates.
 */
71
vec4 getElement3DNormalized(in sampler3D tex, in TextureParameters3D texParams, in vec3 texCoords) {
schultezub's avatar
schultezub committed
72
    //vec2 texCoordsTransformed = (texParams.matrix_ * vec4(texCoords, 0.0, 1.0)).xy;
73
    return texture(tex, texCoords);
schultezub's avatar
schultezub committed
74
}
75 76 77 78

/**
 * Transforms texture coordinates for texture \a tex to world coordinates using the texture's
 * texture-to-world matrix.
79
 * \param	texParams   TextureParameters3D struct with texture for lookup
80 81 82
 * \param   texCoords   texture coordinates
 * \return  \a texCoords transformes to woorld coordinates.
 */
83 84
vec4 textureToWorld(in TextureParameters3D texParams, in vec3 texCoords) {
    return texParams._textureToWorldMatrix * vec4(texCoords, 1.0);
85 86
}

87 88 89 90 91 92 93 94 95 96 97
/**
 * Transforms world coordinates for texture \a tex to texture coordinates using the texture's
 * world-to-texture matrix.
 * \param	texParams   TextureParameters3D struct with texture for lookup
 * \param   worldCoords world coordinates
 * \return  \a texCoords transformes to texture coordinates.
 */
vec4 worldToTexture(in TextureParameters3D texParams, in vec3 worldCoords) {
    return texParams._worldToTextureMatrix * vec4(worldCoords, 1.0);
}

98
float applyRealWorldMapping(in TextureParameters3D tex, in float value) {
99 100 101
    return (value + tex._realWorldMapping.x) * tex._realWorldMapping.y;
}

102
float applyInverseRealWorldMapping(in TextureParameters3D tex, in float value) {
103 104
    return (value - tex._realWorldMapping.x) / tex._realWorldMapping.y;
}