| // |
| // Copyright 2002 The ANGLE Project Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| // |
| |
| #include "compiler/translator/BuiltInFunctionEmulatorGLSL.h" |
| |
| #include "angle_gl.h" |
| #include "compiler/translator/BuiltInFunctionEmulator.h" |
| #include "compiler/translator/VersionGLSL.h" |
| #include "compiler/translator/tree_util/BuiltIn.h" |
| |
| namespace sh |
| { |
| |
| void InitBuiltInAbsFunctionEmulatorForGLSLWorkarounds(BuiltInFunctionEmulator *emu, |
| sh::GLenum shaderType) |
| { |
| if (shaderType == GL_VERTEX_SHADER) |
| { |
| emu->addEmulatedFunction(BuiltInId::abs_Int1, "int abs_emu(int x) { return x * sign(x); }"); |
| } |
| } |
| |
| void InitBuiltInIsnanFunctionEmulatorForGLSLWorkarounds(BuiltInFunctionEmulator *emu, |
| int targetGLSLVersion) |
| { |
| // isnan() is supported since GLSL 1.3. |
| if (targetGLSLVersion < GLSL_VERSION_130) |
| return; |
| |
| // !(x > 0.0 || x < 0.0 || x == 0.0) will be optimized and always equal to false. |
| emu->addEmulatedFunction( |
| BuiltInId::isnan_Float1, |
| "bool isnan_emu(float x) { return (x > 0.0 || x < 0.0) ? false : x != 0.0; }"); |
| emu->addEmulatedFunction( |
| BuiltInId::isnan_Float2, |
| "bvec2 isnan_emu(vec2 x)\n" |
| "{\n" |
| " bvec2 isnan;\n" |
| " for (int i = 0; i < 2; i++)\n" |
| " {\n" |
| " isnan[i] = (x[i] > 0.0 || x[i] < 0.0) ? false : x[i] != 0.0;\n" |
| " }\n" |
| " return isnan;\n" |
| "}\n"); |
| emu->addEmulatedFunction( |
| BuiltInId::isnan_Float3, |
| "bvec3 isnan_emu(vec3 x)\n" |
| "{\n" |
| " bvec3 isnan;\n" |
| " for (int i = 0; i < 3; i++)\n" |
| " {\n" |
| " isnan[i] = (x[i] > 0.0 || x[i] < 0.0) ? false : x[i] != 0.0;\n" |
| " }\n" |
| " return isnan;\n" |
| "}\n"); |
| emu->addEmulatedFunction( |
| BuiltInId::isnan_Float4, |
| "bvec4 isnan_emu(vec4 x)\n" |
| "{\n" |
| " bvec4 isnan;\n" |
| " for (int i = 0; i < 4; i++)\n" |
| " {\n" |
| " isnan[i] = (x[i] > 0.0 || x[i] < 0.0) ? false : x[i] != 0.0;\n" |
| " }\n" |
| " return isnan;\n" |
| "}\n"); |
| } |
| |
| void InitBuiltInAtanFunctionEmulatorForGLSLWorkarounds(BuiltInFunctionEmulator *emu) |
| { |
| emu->addEmulatedFunction(BuiltInId::atan_Float1_Float1, |
| "emu_precision float atan_emu(emu_precision float y, emu_precision " |
| "float x)\n" |
| "{\n" |
| " if (x > 0.0) return atan(y / x);\n" |
| " else if (x < 0.0 && y >= 0.0) return atan(y / x) + 3.14159265;\n" |
| " else if (x < 0.0 && y < 0.0) return atan(y / x) - 3.14159265;\n" |
| " else return 1.57079632 * sign(y);\n" |
| "}\n"); |
| static const std::array<TSymbolUniqueId, 4> ids = { |
| BuiltInId::atan_Float1_Float1, |
| BuiltInId::atan_Float2_Float2, |
| BuiltInId::atan_Float3_Float3, |
| BuiltInId::atan_Float4_Float4, |
| }; |
| for (int dim = 2; dim <= 4; ++dim) |
| { |
| std::stringstream ss = sh::InitializeStream<std::stringstream>(); |
| ss << "emu_precision vec" << dim << " atan_emu(emu_precision vec" << dim |
| << " y, emu_precision vec" << dim << " x)\n" |
| << "{\n" |
| " return vec" |
| << dim << "("; |
| for (int i = 0; i < dim; ++i) |
| { |
| ss << "atan_emu(y[" << i << "], x[" << i << "])"; |
| if (i < dim - 1) |
| { |
| ss << ", "; |
| } |
| } |
| ss << ");\n" |
| "}\n"; |
| emu->addEmulatedFunctionWithDependency(BuiltInId::atan_Float1_Float1, ids[dim - 1], |
| ss.str().c_str()); |
| } |
| } |
| |
| // Emulate built-in functions missing from GLSL 1.30 and higher |
| void InitBuiltInFunctionEmulatorForGLSLMissingFunctions(BuiltInFunctionEmulator *emu, |
| sh::GLenum shaderType, |
| int targetGLSLVersion) |
| { |
| // Emulate packUnorm2x16 and unpackUnorm2x16 (GLSL 4.10) |
| if (targetGLSLVersion < GLSL_VERSION_410) |
| { |
| // clang-format off |
| emu->addEmulatedFunction(BuiltInId::packUnorm2x16_Float2, |
| "uint packUnorm2x16_emu(vec2 v)\n" |
| "{\n" |
| " int x = int(round(clamp(v.x, 0.0, 1.0) * 65535.0));\n" |
| " int y = int(round(clamp(v.y, 0.0, 1.0) * 65535.0));\n" |
| " return uint((y << 16) | (x & 0xFFFF));\n" |
| "}\n"); |
| |
| emu->addEmulatedFunction(BuiltInId::unpackUnorm2x16_UInt1, |
| "vec2 unpackUnorm2x16_emu(uint u)\n" |
| "{\n" |
| " float x = float(u & 0xFFFFu) / 65535.0;\n" |
| " float y = float(u >> 16) / 65535.0;\n" |
| " return vec2(x, y);\n" |
| "}\n"); |
| // clang-format on |
| } |
| |
| // Emulate packSnorm2x16, packHalf2x16, unpackSnorm2x16, and unpackHalf2x16 (GLSL 4.20) |
| // by using floatBitsToInt, floatBitsToUint, intBitsToFloat, and uintBitsToFloat (GLSL 3.30). |
| if (targetGLSLVersion >= GLSL_VERSION_330 && targetGLSLVersion < GLSL_VERSION_420) |
| { |
| // clang-format off |
| emu->addEmulatedFunction(BuiltInId::packSnorm2x16_Float2, |
| "uint packSnorm2x16_emu(vec2 v)\n" |
| "{\n" |
| " #if defined(GL_ARB_shading_language_packing)\n" |
| " return packSnorm2x16(v);\n" |
| " #else\n" |
| " int x = int(round(clamp(v.x, -1.0, 1.0) * 32767.0));\n" |
| " int y = int(round(clamp(v.y, -1.0, 1.0) * 32767.0));\n" |
| " return uint((y << 16) | (x & 0xFFFF));\n" |
| " #endif\n" |
| "}\n"); |
| emu->addEmulatedFunction(BuiltInId::unpackSnorm2x16_UInt1, |
| "#if !defined(GL_ARB_shading_language_packing)\n" |
| " float fromSnorm(uint x)\n" |
| " {\n" |
| " int xi = (int(x) & 0x7FFF) - (int(x) & 0x8000);\n" |
| " return clamp(float(xi) / 32767.0, -1.0, 1.0);\n" |
| " }\n" |
| "#endif\n" |
| "\n" |
| "vec2 unpackSnorm2x16_emu(uint u)\n" |
| "{\n" |
| " #if defined(GL_ARB_shading_language_packing)\n" |
| " return unpackSnorm2x16(u);\n" |
| " #else\n" |
| " uint y = (u >> 16);\n" |
| " uint x = u;\n" |
| " return vec2(fromSnorm(x), fromSnorm(y));\n" |
| " #endif\n" |
| "}\n"); |
| // Functions uint f32tof16(float val) and float f16tof32(uint val) are |
| // based on the OpenGL redbook Appendix Session "Floating-Point Formats Used in OpenGL". |
| emu->addEmulatedFunction(BuiltInId::packHalf2x16_Float2, |
| "#if !defined(GL_ARB_shading_language_packing)\n" |
| " uint f32tof16(float val)\n" |
| " {\n" |
| " uint f32 = floatBitsToUint(val);\n" |
| " uint f16 = 0u;\n" |
| " uint sign = (f32 >> 16) & 0x8000u;\n" |
| " int exponent = int((f32 >> 23) & 0xFFu) - 127;\n" |
| " uint mantissa = f32 & 0x007FFFFFu;\n" |
| " if (exponent == 128)\n" |
| " {\n" |
| " // Infinity or NaN\n" |
| " // NaN bits that are masked out by 0x3FF get discarded.\n" |
| " // This can turn some NaNs to infinity, but this is allowed by the spec.\n" |
| " f16 = sign | (0x1Fu << 10);\n" |
| " f16 |= (mantissa & 0x3FFu);\n" |
| " }\n" |
| " else if (exponent > 15)\n" |
| " {\n" |
| " // Overflow - flush to Infinity\n" |
| " f16 = sign | (0x1Fu << 10);\n" |
| " }\n" |
| " else if (exponent > -15)\n" |
| " {\n" |
| " // Representable value\n" |
| " exponent += 15;\n" |
| " mantissa >>= 13;\n" |
| " f16 = sign | uint(exponent << 10) | mantissa;\n" |
| " }\n" |
| " else\n" |
| " {\n" |
| " f16 = sign;\n" |
| " }\n" |
| " return f16;\n" |
| " }\n" |
| "#endif\n" |
| "\n" |
| "uint packHalf2x16_emu(vec2 v)\n" |
| "{\n" |
| " #if defined(GL_ARB_shading_language_packing)\n" |
| " return packHalf2x16(v);\n" |
| " #else\n" |
| " uint x = f32tof16(v.x);\n" |
| " uint y = f32tof16(v.y);\n" |
| " return (y << 16) | x;\n" |
| " #endif\n" |
| "}\n"); |
| emu->addEmulatedFunction(BuiltInId::unpackHalf2x16_UInt1, |
| "#if !defined(GL_ARB_shading_language_packing)\n" |
| " float f16tof32(uint val)\n" |
| " {\n" |
| " uint sign = (val & 0x8000u) << 16;\n" |
| " int exponent = int((val & 0x7C00u) >> 10);\n" |
| " uint mantissa = val & 0x03FFu;\n" |
| " float f32 = 0.0;\n" |
| " if(exponent == 0)\n" |
| " {\n" |
| " if (mantissa != 0u)\n" |
| " {\n" |
| " const float scale = 1.0 / (1 << 24);\n" |
| " f32 = scale * mantissa;\n" |
| " }\n" |
| " }\n" |
| " else if (exponent == 31)\n" |
| " {\n" |
| " return uintBitsToFloat(sign | 0x7F800000u | mantissa);\n" |
| " }\n" |
| " else\n" |
| " {\n" |
| " exponent -= 15;\n" |
| " float scale;\n" |
| " if(exponent < 0)\n" |
| " {\n" |
| " // The negative unary operator is buggy on OSX.\n" |
| " // Work around this by using abs instead.\n" |
| " scale = 1.0 / (1 << abs(exponent));\n" |
| " }\n" |
| " else\n" |
| " {\n" |
| " scale = 1 << exponent;\n" |
| " }\n" |
| " float decimal = 1.0 + float(mantissa) / float(1 << 10);\n" |
| " f32 = scale * decimal;\n" |
| " }\n" |
| "\n" |
| " if (sign != 0u)\n" |
| " {\n" |
| " f32 = -f32;\n" |
| " }\n" |
| "\n" |
| " return f32;\n" |
| " }\n" |
| "#endif\n" |
| "\n" |
| "vec2 unpackHalf2x16_emu(uint u)\n" |
| "{\n" |
| " #if defined(GL_ARB_shading_language_packing)\n" |
| " return unpackHalf2x16(u);\n" |
| " #else\n" |
| " uint y = (u >> 16);\n" |
| " uint x = u & 0xFFFFu;\n" |
| " return vec2(f16tof32(x), f16tof32(y));\n" |
| " #endif\n" |
| "}\n"); |
| // clang-format on |
| } |
| } |
| |
| } // namespace sh |
