| 1 | /****************************************************************************** |
| 2 | * Arachnoid Graphics Plugin for Mupen64Plus |
| 3 | * http://bitbucket.org/wahrhaft/mupen64plus-video-arachnoid/ |
| 4 | * |
| 5 | * Copyright (C) 2007 Kristofer Karlsson, Rickard Niklasson |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU General Public License |
| 9 | * as published by the Free Software Foundation; either version 2 |
| 10 | * of the License, or (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; if not, write to the Free Software |
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
| 20 | *****************************************************************************/ |
| 21 | |
| 22 | //***************************************************************************** |
| 23 | // |
| 24 | // NOTE THAT THIS FILE IS BASED ON MATERIAL FROM glN64. |
| 25 | // http://gln64.emulation64.com/ |
| 26 | // |
| 27 | //***************************************************************************** |
| 28 | |
| 29 | #include "CombinerStageCreator.h" |
| 30 | |
| 31 | //----------------------------------------------------------------------------- |
| 32 | //* Set Stage |
| 33 | //! Function used to set combiner stage, tries to simplify and optimize as |
| 34 | //! much as possible. |
| 35 | //! From glN64 |
| 36 | //! @param[in] combineCycle Values to be added/subracted/multiplied and interpolated. |
| 37 | //! @param[out] stageOut Simplified combine cycle with combiner formula. |
| 38 | //----------------------------------------------------------------------------- |
| 39 | void setStage(CombineCycle* combineCycle, CombinerStage* stageOut) |
| 40 | { |
| 41 | // Load the first operand |
| 42 | stageOut->op[0].op = LOAD; |
| 43 | stageOut->op[0].param1 = combineCycle->loadValue; |
| 44 | stageOut->numOps = 1; |
| 45 | |
| 46 | // If we're just subtracting zero, skip it |
| 47 | if (combineCycle->subValue != ZERO) |
| 48 | { |
| 49 | if (combineCycle->subValue == stageOut->op[0].param1) |
| 50 | stageOut->op[0].param1 = ZERO; |
| 51 | else |
| 52 | { |
| 53 | //Subract operation |
| 54 | stageOut->op[1].op = SUB; |
| 55 | stageOut->op[1].param1 = combineCycle->subValue; |
| 56 | stageOut->numOps++; |
| 57 | } |
| 58 | } |
| 59 | |
| 60 | //Multiply operation |
| 61 | if ((stageOut->numOps > 1) || (stageOut->op[0].param1 != ZERO)) |
| 62 | { |
| 63 | if (combineCycle->multValue == ZERO) |
| 64 | { |
| 65 | stageOut->numOps = 1; |
| 66 | stageOut->op[0].op = LOAD; |
| 67 | stageOut->op[0].param1 = ZERO; |
| 68 | } |
| 69 | else |
| 70 | { |
| 71 | if ( stageOut->numOps == 1 && stageOut->op[0].param1 == ONE ) |
| 72 | { |
| 73 | //LOAD |
| 74 | stageOut->op[0].param1 = combineCycle->multValue; |
| 75 | } |
| 76 | else |
| 77 | { |
| 78 | //MULT |
| 79 | stageOut->op[stageOut->numOps].op = MUL; |
| 80 | stageOut->op[stageOut->numOps].param1 = combineCycle->multValue; |
| 81 | stageOut->numOps++; |
| 82 | } |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | //Don't bother adding zero |
| 87 | if (combineCycle->addValue != ZERO) |
| 88 | { |
| 89 | // If all we have so far is zero, then load this instead |
| 90 | if ((stageOut->numOps == 1) && (stageOut->op[0].param1 == ZERO)) |
| 91 | { |
| 92 | stageOut->op[0].param1 = combineCycle->addValue; |
| 93 | } |
| 94 | else |
| 95 | { |
| 96 | stageOut->op[stageOut->numOps].op = ADD; |
| 97 | stageOut->op[stageOut->numOps].param1 = combineCycle->addValue; |
| 98 | stageOut->numOps++; |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | // Handle interpolation |
| 103 | if ((stageOut->numOps == 4) && (stageOut->op[1].param1 == stageOut->op[3].param1)) |
| 104 | { |
| 105 | stageOut->numOps = 1; |
| 106 | stageOut->op[0].op = INTERPOLATE; |
| 107 | stageOut->op[0].param2 = stageOut->op[1].param1; |
| 108 | stageOut->op[0].param3 = stageOut->op[2].param1; |
| 109 | } |
| 110 | } |