1 | /* -*- mode: c++; c-basic-offset: 4; indent-tabs-mode: nil -*- */ |
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2 | /* |
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3 | * ====================================================================== |
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4 | * AUTHOR: Wei Qiao <qiaow@purdue.edu> |
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5 | * Purdue Rendering and Perceptualization Lab (PURPL) |
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6 | * |
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7 | * Copyright (c) 2004-2012 HUBzero Foundation, LLC |
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8 | * |
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9 | * See the file "license.terms" for information on usage and |
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10 | * redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES. |
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11 | * ====================================================================== |
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12 | */ |
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13 | |
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14 | // update positions based on velocity |
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15 | |
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16 | #include "common.cg" |
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17 | |
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18 | float4 main(in float2 uv : TEXCOORD0, |
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19 | uniform samplerRECT pos_tex, |
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20 | uniform samplerRECT init_pos_tex, |
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21 | uniform sampler3D vel_tex, |
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22 | // uniform sampler1D tf_tex, |
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23 | uniform float timestep, |
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24 | uniform float max, |
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25 | uniform float mode, |
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26 | uniform float3 scale) : COLOR |
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27 | { |
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28 | float4 ret; |
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29 | /* |
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30 | if (mode == 0) { |
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31 | float4 pos = texRECT(pos_tex, uv); |
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32 | float4 vel = tex3D(vel_tex, pos.xyz); |
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33 | ret.xyz = tex1D(tf_tex, vel.x).xyz; |
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34 | ret.w = 1; |
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35 | } else { |
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36 | */ |
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37 | // get previous position |
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38 | float4 pos = texRECT(pos_tex, uv); |
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39 | float time = pos.w; |
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40 | |
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41 | #ifdef EXPIRE |
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42 | time -= timestep; |
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43 | |
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44 | // Lifetime ended? |
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45 | if (time < 0) { |
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46 | return texRECT(init_pos_tex, uv); |
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47 | } |
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48 | #endif |
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49 | |
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50 | //reconstruct negative value |
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51 | float4 vel = float4(tex3D(vel_tex, pos.xyz).yzw, 0.0) * 2.0 - float4(1.0, 1.0, 1.0, 0.0f); |
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52 | vel = vel * max; |
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53 | //vel *= float4(scale, 1); |
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54 | ret = pos + (vel * timestep); |
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55 | |
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56 | //not drawing if the particle is out of bound |
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57 | if (ret.x < 0 || ret.x > 1 || ret.y < 0 || ret.y > 1 || ret.z < 0 || ret.z > 1) { |
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58 | ret = texRECT(init_pos_tex, uv); |
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59 | } else { |
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60 | ret.w = time; |
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61 | } |
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62 | // } |
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63 | |
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64 | return ret; |
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65 | } |
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