/**

 * MojoShader; generate shader programs from bytecode of compiled

 *  Direct3D shaders.

 *

 * Please see the file LICENSE.txt in the source's root directory.

 *

 *  This file written by Ryan C. Gordon.

 */

#ifndef __INCL_MOJOSHADER_H_

#define __INCL_MOJOSHADER_H_

#ifdef __cplusplus

extern "C" {

#endif

/*

 * For determining the version of MojoShader you are using:

 *    const int compiled_against = MOJOSHADER_VERSION;

 *    const int linked_against = MOJOSHADER_version();

 *

 * The version is a single integer that increments, not a major/minor value.

 */

#define MOJOSHADER_VERSION 1

int MOJOSHADER_version(void);

/*

 * These allocators work just like the C runtime's malloc() and free()

 *  (in fact, they probably use malloc() and free() internally if you don't

 *  specify your own allocator, but don't rely on that behaviour).

 * (data) is the pointer you supplied when specifying these allocator

 *  callbacks, in case you need instance-specific data...it is passed through

 *  to your allocator unmolested, and can be NULL if you like.

 */

typedef void *(*MOJOSHADER_malloc)(int bytes, void *data);

typedef void (*MOJOSHADER_free)(void *ptr, void *data);

/*

 * These are enum values, but they also can be used in bitmasks, so we can

 *  test if an opcode is acceptable: if (op->shader_types & ourtype) {} ...

 */

typedef enum

{

    MOJOSHADER_TYPE_UNKNOWN  = 0,

    MOJOSHADER_TYPE_PIXEL    = (1 << 0),

    MOJOSHADER_TYPE_VERTEX   = (1 << 1),

    MOJOSHADER_TYPE_GEOMETRY = (1 << 2),  /* (not supported yet.) */

    MOJOSHADER_TYPE_ANY = 0xFFFFFFFF   /* used for bitmasks */

} MOJOSHADER_shaderType;

/*

 * Data types for vertex attribute streams.

 */

typedef enum

{

    MOJOSHADER_ATTRIBUTE_BYTE,

    MOJOSHADER_ATTRIBUTE_UBYTE,

    MOJOSHADER_ATTRIBUTE_SHORT,

    MOJOSHADER_ATTRIBUTE_USHORT,

    MOJOSHADER_ATTRIBUTE_INT,

    MOJOSHADER_ATTRIBUTE_UINT,

    MOJOSHADER_ATTRIBUTE_FLOAT,

    MOJOSHADER_ATTRIBUTE_DOUBLE

} MOJOSHADER_attributeType;

/*

 * Data types for uniforms. See MOJOSHADER_uniform for more information.

 */

typedef enum

{

    MOJOSHADER_UNIFORM_FLOAT,

    MOJOSHADER_UNIFORM_INT,

    MOJOSHADER_UNIFORM_BOOL,

} MOJOSHADER_uniformType;

/*

 * These are the uniforms to be set for a shader. "Uniforms" are what Direct3D

 *  calls "Constants" ... IDirect3DDevice::SetVertexShaderConstantF() would

 *  need this data, for example. These integers are register indexes. So if

 *  index==6 and type==MOJOSHADER_UNIFORM_FLOAT, that means we'd expect a

 *  4-float vector to be specified for what would be register "c6" in D3D

 *  assembly language, before drawing with the shader.

 * (name) is a profile-specific variable name; it may be NULL if it isn't

 *  applicable to the requested profile.

 */

typedef struct

{

    MOJOSHADER_uniformType type;

    int index;

    const char *name;

} MOJOSHADER_uniform;

/*

 * Data types for samplers. See MOJOSHADER_sampler for more information.

 */

typedef enum

{

    MOJOSHADER_SAMPLER_2D,

    MOJOSHADER_SAMPLER_CUBE,

    MOJOSHADER_SAMPLER_VOLUME,

} MOJOSHADER_samplerType;

/*

 * These are the samplers to be set for a shader. ...

 *  IDirect3DDevice::SetTexture() would need this data, for example.

 * These integers are the sampler "stage". So if index==6 and

 *  type==MOJOSHADER_SAMPLER_2D, that means we'd expect a regular 2D texture

 *  to be specified for what would be register "s6" in D3D assembly language,

 *  before drawing with the shader.

 * (name) is a profile-specific variable name; it may be NULL if it isn't

 *  applicable to the requested profile.

 */

typedef struct

{

    MOJOSHADER_samplerType type;

    int index;

    const char *name;

} MOJOSHADER_sampler;

/*

 * Data types for attributes. See MOJOSHADER_attribute for more information.

 */

typedef enum

{

    MOJOSHADER_USAGE_POSITION,

    MOJOSHADER_USAGE_BLENDWEIGHT,

    MOJOSHADER_USAGE_BLENDINDICES,

    MOJOSHADER_USAGE_NORMAL,

    MOJOSHADER_USAGE_POINTSIZE,

    MOJOSHADER_USAGE_TEXCOORD,

    MOJOSHADER_USAGE_TANGENT,

    MOJOSHADER_USAGE_BINORMAL,

    MOJOSHADER_USAGE_TESSFACTOR,

    MOJOSHADER_USAGE_POSITIONT,

    MOJOSHADER_USAGE_COLOR,

    MOJOSHADER_USAGE_FOG,

    MOJOSHADER_USAGE_DEPTH,

    MOJOSHADER_USAGE_SAMPLE,

    MOJOSHADER_USAGE_TOTAL,  /* housekeeping value; not ever returned. */

} MOJOSHADER_usage;

/*

 * These are the attributes to be set for a shader. "Attributes" are what

 *  Direct3D calls "Vertex Declarations Usages" ...

 *  IDirect3DDevice::CreateVertexDeclaration() would need this data, for

 *  example. Each attribute is associated with an array of data that uses one

 *  element per-vertex. So if usage==MOJOSHADER_USAGE_COLOR and index==1, that

 *  means we'd expect a secondary color array to be bound to this shader

 *  before drawing.

 * (name) is a profile-specific variable name; it may be NULL if it isn't

 *  applicable to the requested profile.

 */

typedef struct

{

    MOJOSHADER_usage usage;

    int index;

    const char *name;

} MOJOSHADER_attribute;

/*

 * Structure used to return data from parsing of a shader...

 */

typedef struct

{

    /*

     * Human-readable error, if there is one. Will be NULL if there was no

     *  error. The string will be UTF-8 encoded, and English only. Most of

     *  these shouldn't be shown to the end-user anyhow.

     */

    const char *error;

    /*

     * The name of the profile used to parse the shader. Will be NULL on error.

     */

    const char *profile;

    /*

     * Bytes of output from parsing. Most profiles produce a string of source

     *  code, but profiles that do binary output may not be text at all.

     *  Will be NULL on error.

     */

    const char *output;

    /*

     * Byte count for output, not counting any null terminator. Most profiles

     *  produce an ASCII string of source code (which will be null-terminated

     *  even though that null char isn't included in output_len), but profiles

     *  that do binary output may not be text at all. Will be 0 on error.

     */

    int output_len;

    /*

     * Count of Direct3D instructions we parsed. This is meaningless in terms

     *  of the actual output, as the profile will probably grow or reduce

     *  the count (or for high-level languages, not have that information at

     *  all), but it can give you a rough idea of the size of your shader.

     *  Will be zero on error.

     */

    int instruction_count;

    /*

     * The type of shader we parsed. Will be MOJOSHADER_TYPE_UNKNOWN on error.

     */

    MOJOSHADER_shaderType shader_type;

    /*

     * The shader's major version. If this was a "vs_3_0", this would be 3.

     */

    int major_ver;

    /*

     * The shader's minor version. If this was a "ps_1_4", this would be 4.

     *  Two notes: for "vs_2_x", this is 1, and for "vs_3_sw", this is 255.

     */

    int minor_ver;

    /*

     * The number of elements pointed to by (uniforms).

     */

    int uniform_count;

    /*

     * (uniform_count) elements of data that specify Uniforms to be set for

     *  this shader. See discussion on MOJOSHADER_uniform for details.

     * This can be NULL on error or if (uniform_count) is zero.

     */

    MOJOSHADER_uniform *uniforms;

    /*

     * The number of elements pointed to by (samplers).

     */

    int sampler_count;

    /*

     * (sampler_count) elements of data that specify Samplers to be set for

     *  this shader. See discussion on MOJOSHADER_sampler for details.

     * This can be NULL on error or if (sampler_count) is zero.

     */

    MOJOSHADER_sampler *samplers;

    /*

     * The number of elements pointed to by (attributes).

     */

    int attribute_count;

    /*

     * (attribute_count) elements of data that specify Attributes to be set

     *  for this shader. See discussion on MOJOSHADER_attribute for details.

     * This can be NULL on error or if (attribute_count) is zero.

     */

    MOJOSHADER_attribute *attributes;

    /*

     * This is the malloc implementation you passed to MOJOSHADER_parse().

     */

    MOJOSHADER_malloc malloc;

    /*

     * This is the free implementation you passed to MOJOSHADER_parse().

     */

    MOJOSHADER_free free;

    /*

     * This is the pointer you passed as opaque data for your allocator.

     */

    void *malloc_data;

} MOJOSHADER_parseData;

/*

 * Profile string for Direct3D assembly language output.

 */

#define MOJOSHADER_PROFILE_D3D "d3d"

/*

 * Profile string for passthrough of the original bytecode, unchanged.

 */

#define MOJOSHADER_PROFILE_PASSTHROUGH "passthrough"

/*

 * Profile string for GLSL: OpenGL high-level shader language output.

 */

#define MOJOSHADER_PROFILE_GLSL "glsl"

/*

 * Parse a compiled Direct3D shader's bytecode.

 *

 * This is your primary entry point into MojoShader. You need to pass it

 *  a compiled D3D shader and tell it which "profile" you want to use to

 *  convert it into useful data.

 *

 * The available profiles are the set of MOJOSHADER_PROFILE_* defines.

 *  Note that MojoShader may be built without support for all listed

 *  profiles (in which case using one here will return with an error).

 *

 * As parsing requires some memory to be allocated, you may provide a custom

 *  allocator to this function, which will be used to allocate/free memory.

 *  They function just like malloc() and free(). We do not use realloc().

 *  If you don't care, pass NULL in for the allocator functions. If your

 *  allocator needs instance-specific data, you may supply it with the

 *  (d) parameter. This pointer is passed as-is to your (m) and (f) functions.

 *

 * This function returns a MOJOSHADER_parseData.

 *

 * This function will never return NULL, even if the system is completely

 *  out of memory upon entry (in which case, this function returns a static

 *  MOJOSHADER_parseData object, which is still safe to pass to

 *  MOJOSHADER_freeParseData()).

 *

 * This function is thread safe, so long as (m) and (f) are too, and that

 *  (tokenbuf) remains intact for the duration of the call. This allows you

 *  to parse several shaders on separate CPU cores at the same time.

 */

const MOJOSHADER_parseData *MOJOSHADER_parse(const char *profile,

                                             const unsigned char *tokenbuf,

                                             const unsigned int bufsize,

                                             MOJOSHADER_malloc m,

                                             MOJOSHADER_free f,

                                             void *d);

/*

 * Call this to dispose of parsing results when you are done with them.

 *  This will call the MOJOSHADER_free function you provided to

 *  MOJOSHADER_parse multiple times, if you provided one.

 *  Passing a NULL here is a safe no-op.

 *

 * This function is thread safe, so long as any allocator you passed into

 *  MOJOSHADER_parse() is, too.

 */

void MOJOSHADER_freeParseData(const MOJOSHADER_parseData *data);

/*

 * Prepare MojoShader to manage OpenGL shaders.

 *

 * You do not need to call this if all you want is MOJOSHADER_parse().

 *

 * You must call this once AFTER you have successfully built your GL context

 *  and made it current. This function will lookup the GL functions it needs

 *  through the callback you supply, after which it may call them at any time

 *  up until you call MOJOSHADER_glDeinit(). The lookup function is neither

 *  stored nor used by MojoShader after this function returns.

 *

 * (profile) is an OpenGL-specific MojoShader profile, which decides how

 *  Direct3D bytecode shaders get turned into OpenGL programs, and how they

 *  are fed to the GL.

 *

 * (lookup) is a callback that is used to load GL entry points. This callback

 *  has to look up base GL functions and extension entry points.

 *

 * As MojoShader requires some memory to be allocated, you may provide a

 *  custom allocator to this function, which will be used to allocate/free

 *  memory. They function just like malloc() and free(). We do not use

 *  realloc(). If you don't care, pass NULL in for the allocator functions.

 *  If your allocator needs instance-specific data, you may supply it with the

 *  (d) parameter. This pointer is passed as-is to your (m) and (f) functions.

 *

 * Returns zero on error, non-zero on success.

 *

 * This call is NOT thread safe! It must return success before you may call

 *  any other MOJOSHADER_gl* function. Also, as most OpenGL implementations

 *  are not thread safe, you should probably only call this from the same

 *  thread that created the GL context.

 */

int MOJOSHADER_glInit(const char *profile,

                      void *(*lookup)(const char *fnname),

                      MOJOSHADER_malloc m, MOJOSHADER_free f, void *d);

/*

 * "Shaders" refer to individual vertex or pixel programs, and are created

 *  by "compiling" Direct3D shader bytecode. A vertex and pixel shader are

 *  "linked" into a "Program" before you can use them to render.

 *

 * To the calling application, these are opaque handles.

 */

typedef struct MOJOSHADER_glShader MOJOSHADER_glShader;

typedef struct MOJOSHADER_glProgram MOJOSHADER_glProgram;

/*

 * Compile a buffer of Direct3D shader bytecode into an OpenGL shader.

 *  You still need to link the shader before you may render with it.

 *

 *   (tokenbuf) is a buffer of Direct3D shader bytecode.

 *   (bufsize) is the size, in bytes, of the bytecode buffer.

 *

 * Returns NULL on error, or a shader handle on success.

 */

MOJOSHADER_glShader *MOJOSHADER_glCompileShader(const unsigned char *tokenbuf,

                                                const unsigned int bufsize);

/*

 * Link a vertex and pixel shader into an OpenGL program.

 *  (vshader) or (pshader) can be NULL, to specify that the GL should use the

 *  fixed-function pipeline instead of the programmable pipeline for that

 *  portion of the work. You can reuse shaders in various combinations across

 *  multiple programs, by relinking different pairs.

 *

 * It is illegal to give a vertex shader for (pshader) or a pixel shader

 *  for (vshader).

 *

 * Once you have successfully linked a program, you may render with it.

 *

 * Returns NULL on error, or a program handle on success.

 */

MOJOSHADER_glProgram *MOJOSHADER_glLinkProgram(MOJOSHADER_glShader *vshader,

                                               MOJOSHADER_glShader *pshader);

/*

 * This binds the program (using, for example, glUseProgramObjectARB()), and

 *  disables all the client-side arrays so we can reset them with new values

 *  if appropriate.

 *

 * Call with NULL to disable the programmable pipeline and all enabled

 *  client-side arrays.

 *

 * After binding a program, you should update any uniforms you care about

 *  with MOJOSHADER_glSetVertexShaderUniformF() (etc), set any vertex arrays

 *  you want to use with MOJOSHADER_glSetVertexAttribute(), and finally call

 *  MOJOSHADER_glProgramReady() to commit everything to the GL. Then you may

 *  begin drawing through standard GL entry points.

 */

void MOJOSHADER_glBindProgram(MOJOSHADER_glProgram *program);

/*

 * Set a floating-point uniform value (what Direct3D calls a "constant").

 *

 * There is a single array of 4-float "registers" shared by all vertex shaders.

 *  This is the "c" register file in Direct3D (c0, c1, c2, etc...)

 *  MojoShader will take care of synchronizing this internal array with the

 *  appropriate variables in the GL shaders.

 *

 * (idx) is the index into the internal array: 0 is the first four floats,

 *  1 is the next four, etc.

 * (data) is a pointer to (vec4count*4) floats.

 */

void MOJOSHADER_glSetVertexShaderUniformF(unsigned int idx, const float *data,

                                          unsigned int vec4count);

/*

 * Set an integer uniform value (what Direct3D calls a "constant").

 *

 * There is a single array of 4-int "registers" shared by all vertex shaders.

 *  This is the "i" register file in Direct3D (i0, i1, i2, etc...)

 *  MojoShader will take care of synchronizing this internal array with the

 *  appropriate variables in the GL shaders.

 *

 * (idx) is the index into the internal array: 0 is the first four ints,

 *  1 is the next four, etc.

 * (data) is a pointer to (ivec4count*4) ints.

 */

void MOJOSHADER_glSetVertexShaderUniformI(unsigned int idx, const int *data,

                                          unsigned int ivec4count);

/*

 * Set a boolean uniform value (what Direct3D calls a "constant").

 *

 * There is a single array of "registers" shared by all vertex shaders.

 *  This is the "b" register file in Direct3D (b0, b1, b2, etc...)

 *  MojoShader will take care of synchronizing this internal array with the

 *  appropriate variables in the GL shaders.

 *

 * Unlike the float and int counterparts, booleans are single values, not

 *  four-element vectors...so idx==1 is the second boolean in the internal

 *  array, not the fifth.

 *

 * Non-zero values are considered "true" and zero is considered "false".