source: downloads/RenderSystems/GL/src/atifs/include/ps_1_4.h @ 6

/*
-----------------------------------------------------------------------------
This source file is part of OGRE
(Object-oriented Graphics Rendering Engine)
For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2006 Torus Knot Software Ltd
Also see acknowledgements in Readme.html

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA, or go to
http://www.gnu.org/copyleft/lesser.txt.

You may alternatively use this source under the terms of a specific version of
the OGRE Unrestricted License provided you have obtained such a license from
Torus Knot Software Ltd.
-----------------------------------------------------------------------------
*/


/**
        A number of invaluable references were used to put together this ps.1.x compiler for ATI_fragment_shader execution

        References:
                1. MSDN: DirectX 8.1 Reference
                2. Wolfgang F. Engel "Fundamentals of Pixel Shaders - Introduction to Shader Programming Part III" on gamedev.net
                3. Martin Ecker - XEngine
                4. Shawn Kirst - ps14toATIfs
                5. Jason L. Mitchell "Real-Time 3D Graphics With Pixel Shaders" 
                6. Jason L. Mitchell "1.4 Pixel Shaders"
                7. Jason L. Mitchell and Evan Hart "Hardware Shading with EXT_vertex_shader and ATI_fragment_shader"
                6. ATI 8500 SDK
                7. GL_ATI_fragment_shader extension reference

*/
//---------------------------------------------------------------------------
#ifndef ps_1_4H
#define ps_1_4H

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "OgreGLPrerequisites.h"
#include "Compiler2Pass.h"


//---------------------------------------------------------------------------
// macro to get the size of a static array
#define ARRAYSIZE(array) (sizeof(array)/sizeof(array[0]))

#define ALPHA_BIT 0x08
#define RGB_BITS 0x07

// Context key patterns
#define ckp_PS_BASE 0x1
#define ckp_PS_1_1  0x2
#define ckp_PS_1_2  0x4
#define ckp_PS_1_3  0x8
#define ckp_PS_1_4  0x10

#define ckp_PS_1_4_BASE (ckp_PS_BASE + ckp_PS_1_4)




/** Subclasses Compiler2Pass to provide a ps_1_x compiler that takes DirectX pixel shader assembly
        and converts it to a form that can be used by ATI_fragment_shader OpenGL API
@remarks
        all ps_1_1, ps_1_2, ps_1_3, ps_1_4 assembly instructions are recognized but not all are passed
        on to ATI_fragment_shader.      ATI_fragment_shader does not have an equivelant directive for
        texkill or texdepth instructions.

        The user must provide the GL binding interfaces.

        A Test method is provided to verify the basic operation of the compiler which outputs the test
        results to a file.


*/
class PS_1_4 : public Compiler2Pass{
private:
        enum RWAflags {rwa_NONE = 0, rwa_READ = 1, rwa_WRITE = 2};

        enum MachineInstID {mi_COLOROP1, mi_COLOROP2, mi_COLOROP3, mi_ALPHAOP1, mi_ALPHAOP2,
                                                mi_ALPHAOP3, mi_SETCONSTANTS, mi_PASSTEXCOORD, mi_SAMPLEMAP, mi_TEX,
                                                mi_TEXCOORD, mi_TEXREG2RGB, mi_NOP
        };

        struct  TokenInstType{
          char* Name;
          GLuint ID;

        };

        struct RegisterUsage {
                bool Phase1Write;
                bool Phase2Write;
        };

        // Token ID enumeration
        enum SymbolID {
                // Terminal Tokens section

                // DirectX pixel shader source formats 
                sid_PS_1_4, sid_PS_1_1, sid_PS_1_2, sid_PS_1_3,
                                        
                // PS_BASE
                sid_C0, sid_C1, sid_C2, sid_C3, sid_C4, sid_C5, sid_C6, sid_C7,
                sid_V0, sid_V1,
                sid_ADD, sid_SUB, sid_MUL, sid_MAD, sid_LRP, sid_MOV, sid_CMP, sid_CND,
                sid_DP3, sid_DP4, sid_DEF,
                sid_R, sid_RA, sid_G, sid_GA, sid_B, sid_BA, sid_A, sid_RGBA, sid_RGB,
                sid_RG, sid_RGA, sid_RB, sid_RBA, sid_GB, sid_GBA,
                sid_RRRR, sid_GGGG, sid_BBBB, sid_AAAA,
                sid_X2, sid_X4, sid_D2, sid_SAT,
                sid_BIAS, sid_INVERT, sid_NEGATE, sid_BX2,
                sid_COMMA, sid_VALUE,

                //PS_1_4 sid
                sid_R0, sid_R1, sid_R2, sid_R3, sid_R4, sid_R5,
                sid_T0, sid_T1, sid_T2, sid_T3, sid_T4, sid_T5,
                sid_DP2ADD,
                sid_X8, sid_D8, sid_D4,
                sid_TEXCRD, sid_TEXLD,
                sid_STR, sid_STQ,
                sid_STRDR, sid_STQDQ,
                sid_BEM,
                sid_PHASE,

                //PS_1_1 sid
                sid_1R0, sid_1R1, sid_1T0, sid_1T1, sid_1T2, sid_1T3,
                sid_TEX, sid_TEXCOORD, sid_TEXM3X2PAD,
                sid_TEXM3X2TEX, sid_TEXM3X3PAD, sid_TEXM3X3TEX, sid_TEXM3X3SPEC, sid_TEXM3X3VSPEC,
                sid_TEXREG2AR, sid_TEXREG2GB,
                
                //PS_1_2 side
                sid_TEXREG2RGB, sid_TEXDP3, sid_TEXDP3TEX,

                // common
                sid_SKIP, sid_PLUS,

                // non-terminal tokens section
                sid_PROGRAM, sid_PROGRAMTYPE, sid_DECLCONSTS, sid_DEFCONST,
                sid_CONSTANT, sid_COLOR,
                sid_TEXSWIZZLE, sid_UNARYOP,
                sid_NUMVAL, sid_SEPERATOR, sid_ALUOPS, sid_TEXMASK, sid_TEXOP_PS1_1_3,
                sid_TEXOP_PS1_4,
                sid_ALU_STATEMENT, sid_DSTMODSAT, sid_UNARYOP_ARGS, sid_REG_PS1_4,
                sid_TEX_PS1_4, sid_REG_PS1_1_3, sid_TEX_PS1_1_3, sid_DSTINFO,
                sid_SRCINFO, sid_BINARYOP_ARGS, sid_TERNARYOP_ARGS, sid_TEMPREG,
                sid_DSTMASK, sid_PRESRCMOD, sid_SRCNAME, sid_SRCREP, sid_POSTSRCMOD,
                sid_DSTMOD, sid_DSTSAT, sid_BINARYOP,  sid_TERNARYOP,
                sid_TEXOPS_PHASE1, sid_COISSUE, sid_PHASEMARKER, sid_TEXOPS_PHASE2, 
                sid_TEXREG_PS1_4, sid_TEXOPS_PS1_4, sid_TEXOPS_PS1_1_3, sid_TEXCISCOP_PS1_1_3,


                // last token
                sid_INVALID = BAD_TOKEN // must be last in enumeration
        };

        /// structure used to keep track of arguments and instruction parameters
        struct OpParram {
          GLuint Arg;           // type of argument
          bool Filled;          // has it been filled yet
          GLuint MaskRep;       // Mask/Replicator flags
          GLuint Mod;           // argument modifier
        };

        typedef std::vector<uint> MachineInstContainer;
        //typedef MachineInstContainer::iterator MachineInstIterator;


        // there are 2 phases with 2 subphases each
        enum PhaseType {ptPHASE1TEX, ptPHASE1ALU, ptPHASE2TEX, ptPHASE2ALU };

        struct RegModOffset {
                uint MacroOffset;
                uint RegisterBase;
                uint OpParramsIndex;
        };

        struct MacroRegModify {
                TokenInst *             Macro;
                uint                    MacroSize;
                RegModOffset *  RegMods;
                uint                    RegModSize;

        };

        #define R_BASE  (sid_R0 - GL_REG_0_ATI)
        #define C_BASE  (sid_C0 - GL_CON_0_ATI)
        #define T_BASE  (sid_1T0 - GL_REG_0_ATI)

        // static library database for tokens and BNF rules
        static SymbolDef PS_1_4_SymbolTypeLib[];
        static TokenRule PS_1_x_RulePath[];
        static bool LibInitialized;

        // Static Macro database for ps.1.1 ps.1.2 ps.1.3 instructions

        static TokenInst texreg2ar[];
        static RegModOffset texreg2xx_RegMods[];
        static MacroRegModify texreg2ar_MacroMods;

        static TokenInst texreg2gb[];
        static MacroRegModify texreg2gb_MacroMods;

        static TokenInst texdp3[];
        static RegModOffset texdp3_RegMods[];
        static MacroRegModify texdp3_MacroMods;

        static TokenInst texdp3tex[];
        static RegModOffset texdp3tex_RegMods[];
        static MacroRegModify texdp3tex_MacroMods;

        static TokenInst texm3x2pad[];
        static RegModOffset texm3xxpad_RegMods[];
        static MacroRegModify texm3x2pad_MacroMods;

        static TokenInst texm3x2tex[];
        static RegModOffset texm3xxtex_RegMods[];
        static MacroRegModify texm3x2tex_MacroMods;

        static TokenInst texm3x3pad[];
        static MacroRegModify texm3x3pad_MacroMods;

        static TokenInst texm3x3tex[];
        static MacroRegModify texm3x3tex_MacroMods;

        static TokenInst texm3x3spec[];
        static RegModOffset texm3x3spec_RegMods[];
        static MacroRegModify texm3x3spec_MacroMods;

        static TokenInst texm3x3vspec[];
        static RegModOffset texm3x3vspec_RegMods[];
        static MacroRegModify texm3x3vspec_MacroMods;


        MachineInstContainer mPhase1TEX_mi; /// machine instructions for phase one texture section
        MachineInstContainer mPhase1ALU_mi; /// machine instructions for phase one ALU section
        MachineInstContainer mPhase2TEX_mi; /// machine instructions for phase two texture section
        MachineInstContainer mPhase2ALU_mi; /// machine instructions for phase two ALU section

        MachineInstContainer* mActivePhaseMachineInstructions;
        // vars used during pass 2
        MachineInstID mOpType;
        uint mOpInst;
        bool mDo_Alpha;
        PhaseType mInstructionPhase;
        int mArgCnt;
        int mConstantsPos;

        #define MAXOPPARRAMS 5 // max number of parrams bound to an instruction
        
        OpParram mOpParrams[MAXOPPARRAMS];

        /// keeps track of which registers are written to in each phase
        /// if a register is read from but has not been written to in phase 2
        /// then if it was written to in phase 1 perform a register pass function
        /// at the begining of phase2 so that the register has something worthwhile in it
        /// NB: check ALU and TEX section of phase 1 and phase 2
        /// there are 6 temp registers r0 to r5 to keep track off
        /// checks are performed in pass 2 when building machine instructions
        RegisterUsage Phase_RegisterUsage[6];

        bool mMacroOn; // if true then put all ALU instructions in phase 1

        uint mTexm3x3padCount; // keep track of how many texm3x3pad instructions are used so know which mask to use

        size_t mLastInstructionPos; // keep track of last phase 2 ALU instruction to check for R0 setting
        size_t mSecondLastInstructionPos;

        // keep track if phase marker found: determines which phase the ALU instructions go into
        bool mPhaseMarkerFound; 

#ifdef _DEBUG
        FILE* fp;
        // full compiler test with output results going to a text file
        void testCompile(char* testname, char* teststr, SymbolID* testresult,
                uint testresultsize, GLuint* MachinInstResults = NULL, uint MachinInstResultsSize = 0);
#endif // _DEBUG


        /** attempt to build a machine instruction using current tokens
                determines what phase machine insturction should be in and if an Alpha Op is required
                calls expandMachineInstruction() to expand the token into machine instructions
        */
        bool BuildMachineInst();
        
        void clearMachineInstState();

        bool setOpParram(const SymbolDef* symboldef);

        /** optimizes machine instructions depending on pixel shader context
                only applies to ps.1.1 ps.1.2 and ps.1.3 since they use CISC instructions
                that must be transformed into RISC instructions
        */
        void optimize();

        // the method is expected to be recursive to allow for inline expansion of instructions if required
        bool Pass2scan(const TokenInst * Tokens, const size_t size);

        // supply virtual functions for Compiler2Pass
        /// Pass 1 is completed so now take tokens generated and build machine instructions
        bool doPass2();

        /** Build a machine instruction from token and ready it for expansion
                will expand CISC tokens using macro database

        */
        bool bindMachineInstInPassToFragmentShader(const MachineInstContainer & PassMachineInstructions);

        /** Expand CISC tokens into PS1_4 token equivalents

        */
        bool expandMacro(const MacroRegModify & MacroMod);

        /** Expand Machine instruction into operation type and arguments and put into proper machine
                instruction container
                also expands scaler alpha machine instructions if required

        */
        bool expandMachineInstruction();

        // mainly used by tests - too slow for use in binding
        size_t getMachineInst(size_t Idx);

        size_t getMachineInstCount();

        void addMachineInst(PhaseType phase, const uint inst);

        void clearAllMachineInst();

        void updateRegisterWriteState(const PhaseType phase);

        bool isRegisterReadValid(const PhaseType phase, const int param);

public:

        /// constructor
        PS_1_4();

        /// binds machine instructions generated in Pass 2 to the ATI GL fragment shader
        bool bindAllMachineInstToFragmentShader();

#ifdef _DEBUG
        /// perform compiler tests - only available in _DEBUG mode
        void test();
        void testbinder();

#endif
};


#endif