//
//Copyright (C) 2002-2005  3Dlabs Inc. Ltd.
//Copyright (C) 2012-2013 LunarG, Inc.
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//

#ifndef _BASICTYPES_INCLUDED_
#define _BASICTYPES_INCLUDED_

namespace glslang {

//
// Basic type.  Arrays, vectors, sampler details, etc., are orthogonal to this.
//
enum TBasicType {
    EbtVoid,
    EbtFloat,
    EbtDouble,
    EbtInt,
    EbtUint,
    EbtBool,
    EbtAtomicUint,
    EbtSampler,
    EbtStruct,
    EbtBlock,
    EbtNumTypes
};

//
// Qualifiers and built-ins.  These are mainly used to see what can be read
// or written, and by the machine dependent translator to know which registers
// to allocate variables in.  Since built-ins tend to go to different registers
// than varying or uniform, it makes sense they are peers, not sub-classes.
//
enum TStorageQualifier {
    EvqTemporary,     // For temporaries (within a function), read/write
    EvqGlobal,        // For globals read/write
    EvqConst,         // User-defined constant values, will be semantically constant and constant folded
    EvqVaryingIn,     // pipeline input, read only, also supercategory for all built-ins not included in this enum (see TBuiltInVariable)
    EvqVaryingOut,    // pipeline ouput, read/write, also supercategory for all built-ins not included in this enum (see TBuiltInVariable)
    EvqUniform,       // read only, shared with app
    EvqBuffer,        // read/write, shared with app
    EvqShared,        // compute shader's read/write 'shared' qualifier
    
    // parameters
    EvqIn,            // also, for 'in' in the grammar before we know if it's a pipeline input or an 'in' parameter
    EvqOut,           // also, for 'out' in the grammar before we know if it's a pipeline output or an 'out' parameter
    EvqInOut,
    EvqConstReadOnly, // input; also other read-only types having neither a constant value nor constant-value semantics

    // built-ins read by vertex shader
    EvqVertexId,
    EvqInstanceId,

    // built-ins written by vertex shader
    EvqPosition,
    EvqPointSize,
    EvqClipVertex,

    // built-ins read by fragment shader
    EvqFace,
    EvqFragCoord,
    EvqPointCoord,

    // built-ins written by fragment shader
    EvqFragColor,
    EvqFragDepth,

    // end of list
    EvqLast
};

//
// Subcategories of the TStorageQualifier, simply to give a direct mapping
// between built-in variable names and an numerical value (the enum).
//
// For backward compatibility, there is some redundancy between the
// TStorageQualifier and these.  Both should be maintained accurately.
// However, any new built-in variable (and any existing non-redundant one)
// must follow the pattern that the specific built-in is here, and only its
// general qualifier is in TStorageQualifier.
//
// Something like gl_Position, which is sometimes 'in' and sometimes 'out'
// shows up as two different built-in variables in a single stage, but
// only has a single enum in TBuiltInVariable, so both the
// TStorageQualifier and the TBuitinVariable are needed to distinguish
// between them.
//
enum TBuiltInVariable {
    EbvNone,
    EbvNumWorkGroups,
    EbvWorkGroupSize,
    EbvWorkGroupId,
    EbvLocalInvocationId,
    EbvGlobalInvocationId,
    EbvLocalInvocationIndex,
    EbvVertexId,
    EbvInstanceId,
    EbvPosition,
    EbvPointSize,
    EbvClipVertex,
    EbvClipDistance,
    EbvCullDistance,
    EbvNormal,
    EbvVertex,
    EbvMultiTexCoord0,
    EbvMultiTexCoord1,
    EbvMultiTexCoord2,
    EbvMultiTexCoord3,
    EbvMultiTexCoord4,
    EbvMultiTexCoord5,
    EbvMultiTexCoord6,
    EbvMultiTexCoord7,
    EbvFrontColor,
    EbvBackColor,
    EbvFrontSecondaryColor,
    EbvBackSecondaryColor,
    EbvTexCoord,
    EbvFogFragCoord,
    EbvInvocationId,
    EbvPrimitiveId,
    EbvLayer,
    EbvViewportIndex,
    EbvPatchVertices,
    EbvTessLevelOuter,
    EbvTessLevelInner,
    EbvTessCoord,
    EbvColor,
    EbvSecondaryColor,
    EbvFace,
    EbvFragCoord,
    EbvPointCoord,
    EbvFragColor,
    EbvFragData,
    EbvFragDepth,
    EbvSampleId,
    EbvSamplePosition,
    EbvSampleMask,
    EbvHelperInvocation,

    EbvLast
};

// These will show up in error messages
__inline const char* GetStorageQualifierString(TStorageQualifier q) 
{
    switch (q) {
    case EvqTemporary:      return "temp";           break;
    case EvqGlobal:         return "global";         break;
    case EvqConst:          return "const";          break;
    case EvqConstReadOnly:  return "const (read only)"; break;
    case EvqVaryingIn:      return "in";             break;
    case EvqVaryingOut:     return "out";            break;
    case EvqUniform:        return "uniform";        break;
    case EvqBuffer:         return "buffer";         break;
    case EvqShared:         return "shared";         break;
    case EvqIn:             return "in";             break;
    case EvqOut:            return "out";            break;
    case EvqInOut:          return "inout";          break;
    case EvqVertexId:       return "gl_VertexId";    break;
    case EvqInstanceId:     return "gl_InstanceId";  break;
    case EvqPosition:       return "gl_Position";    break;
    case EvqPointSize:      return "gl_PointSize";   break;
    case EvqClipVertex:     return "gl_ClipVertex";  break;
    case EvqFace:           return "gl_FrontFacing"; break;
    case EvqFragCoord:      return "gl_FragCoord";   break;
    case EvqPointCoord:     return "gl_PointCoord";  break;
    case EvqFragColor:      return "fragColor";      break;
    case EvqFragDepth:      return "gl_FragDepth";   break;
    default:                return "unknown qualifier";
    }
}

__inline const char* GetBuiltInVariableString(TBuiltInVariable v)
{
    switch (v) {
    case EbvNone:                 return "";
    case EbvNumWorkGroups:        return "NumWorkGroups";
    case EbvWorkGroupSize:        return "WorkGroupSize";
    case EbvWorkGroupId:          return "WorkGroupID";
    case EbvLocalInvocationId:    return "LocalInvocationID";
    case EbvGlobalInvocationId:   return "GlobalInvocationID";
    case EbvLocalInvocationIndex: return "LocalInvocationIndex";
    case EbvVertexId:             return "VertexId";
    case EbvInstanceId:           return "InstanceId";
    case EbvPosition:             return "Position";
    case EbvPointSize:            return "PointSize";
    case EbvClipVertex:           return "ClipVertex";
    case EbvClipDistance:         return "ClipDistance";
    case EbvCullDistance:         return "CullDistance";
    case EbvNormal:               return "Normal";
    case EbvVertex:               return "Vertex";
    case EbvMultiTexCoord0:       return "MultiTexCoord0";
    case EbvMultiTexCoord1:       return "MultiTexCoord1";
    case EbvMultiTexCoord2:       return "MultiTexCoord2";
    case EbvMultiTexCoord3:       return "MultiTexCoord3";
    case EbvMultiTexCoord4:       return "MultiTexCoord4";
    case EbvMultiTexCoord5:       return "MultiTexCoord5";
    case EbvMultiTexCoord6:       return "MultiTexCoord6";
    case EbvMultiTexCoord7:       return "MultiTexCoord7";
    case EbvFrontColor:           return "FrontColor";
    case EbvBackColor:            return "BackColor";
    case EbvFrontSecondaryColor:  return "FrontSecondaryColor";
    case EbvBackSecondaryColor:   return "BackSecondaryColor";
    case EbvTexCoord:             return "TexCoord";
    case EbvFogFragCoord:         return "FogFragCoord";
    case EbvInvocationId:         return "InvocationID";
    case EbvPrimitiveId:          return "PrimitiveID";
    case EbvLayer:                return "Layer";
    case EbvViewportIndex:        return "ViewportIndex";
    case EbvPatchVertices:        return "PatchVertices";
    case EbvTessLevelOuter:       return "TessLevelOuter";
    case EbvTessLevelInner:       return "TessLevelInner";
    case EbvTessCoord:            return "TessCoord";
    case EbvColor:                return "Color";
    case EbvSecondaryColor:       return "SecondaryColor";
    case EbvFace:                 return "Face";
    case EbvFragCoord:            return "FragCoord";
    case EbvPointCoord:           return "PointCoord";
    case EbvFragColor:            return "FragColor";
    case EbvFragData:             return "FragData";
    case EbvFragDepth:            return "FragDepth";
    case EbvSampleId:             return "SampleId";
    case EbvSamplePosition:       return "SamplePosition";
    case EbvSampleMask:           return "SampleMaskIn";
    case EbvHelperInvocation:     return "HelperInvocation";
    default:                      return "unknown built-in variable";
    }
}

// In this enum, order matters; users can assume higher precision is a bigger value
// and EpqNone is 0.
enum TPrecisionQualifier {
    EpqNone = 0,
    EpqLow,
    EpqMedium,
    EpqHigh
};

__inline const char* GetPrecisionQualifierString(TPrecisionQualifier p)
{
    switch(p) {
    case EpqNone:   return "";        break;
    case EpqLow:    return "lowp";    break;
    case EpqMedium: return "mediump"; break;
    case EpqHigh:   return "highp";   break;
    default:        return "unknown precision qualifier";
    }
}

} // end namespace glslang

#endif // _BASICTYPES_INCLUDED_
