| // |
| // Copyright (c) 2002-2011 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 "angle_gl.h" |
| #include "compiler/translator/BuiltInFunctionEmulator.h" |
| #include "compiler/translator/BuiltInFunctionEmulatorGLSL.h" |
| #include "compiler/translator/Cache.h" |
| #include "compiler/translator/SymbolTable.h" |
| #include "compiler/translator/VersionGLSL.h" |
| |
| void InitBuiltInFunctionEmulatorForGLSLWorkarounds(BuiltInFunctionEmulator *emu, sh::GLenum shaderType) |
| { |
| // we use macros here instead of function definitions to work around more GLSL |
| // compiler bugs, in particular on NVIDIA hardware on Mac OSX. Macros are |
| // problematic because if the argument has side-effects they will be repeatedly |
| // evaluated. This is unlikely to show up in real shaders, but is something to |
| // consider. |
| |
| const TType *float1 = TCache::getType(EbtFloat); |
| const TType *float2 = TCache::getType(EbtFloat, 2); |
| const TType *float3 = TCache::getType(EbtFloat, 3); |
| const TType *float4 = TCache::getType(EbtFloat, 4); |
| |
| if (shaderType == GL_FRAGMENT_SHADER) |
| { |
| emu->addEmulatedFunction(EOpCos, float1, "webgl_emu_precision float webgl_cos_emu(webgl_emu_precision float a) { return cos(a); }"); |
| emu->addEmulatedFunction(EOpCos, float2, "webgl_emu_precision vec2 webgl_cos_emu(webgl_emu_precision vec2 a) { return cos(a); }"); |
| emu->addEmulatedFunction(EOpCos, float3, "webgl_emu_precision vec3 webgl_cos_emu(webgl_emu_precision vec3 a) { return cos(a); }"); |
| emu->addEmulatedFunction(EOpCos, float4, "webgl_emu_precision vec4 webgl_cos_emu(webgl_emu_precision vec4 a) { return cos(a); }"); |
| } |
| emu->addEmulatedFunction(EOpDistance, float1, float1, "#define webgl_distance_emu(x, y) ((x) >= (y) ? (x) - (y) : (y) - (x))"); |
| emu->addEmulatedFunction(EOpDot, float1, float1, "#define webgl_dot_emu(x, y) ((x) * (y))"); |
| emu->addEmulatedFunction(EOpLength, float1, "#define webgl_length_emu(x) ((x) >= 0.0 ? (x) : -(x))"); |
| emu->addEmulatedFunction(EOpNormalize, float1, "#define webgl_normalize_emu(x) ((x) == 0.0 ? 0.0 : ((x) > 0.0 ? 1.0 : -1.0))"); |
| emu->addEmulatedFunction(EOpReflect, float1, float1, "#define webgl_reflect_emu(I, N) ((I) - 2.0 * (N) * (I) * (N))"); |
| } |
| |
| // 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) |
| { |
| const TType *float2 = TCache::getType(EbtFloat, 2); |
| const TType *uint1 = TCache::getType(EbtUInt); |
| |
| // clang-format off |
| emu->addEmulatedFunction(EOpPackUnorm2x16, float2, |
| "uint webgl_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(EOpUnpackUnorm2x16, uint1, |
| "vec2 webgl_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) |
| { |
| const TType *float2 = TCache::getType(EbtFloat, 2); |
| const TType *uint1 = TCache::getType(EbtUInt); |
| |
| // clang-format off |
| emu->addEmulatedFunction(EOpPackSnorm2x16, float2, |
| "uint webgl_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(EOpUnpackSnorm2x16, uint1, |
| "#if !defined(GL_ARB_shading_language_packing)\n" |
| " float webgl_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 webgl_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(webgl_fromSnorm(x), webgl_fromSnorm(y));\n" |
| " #endif\n" |
| "}\n"); |
| // Functions uint webgl_f32tof16(float val) and float webgl_f16tof32(uint val) are |
| // based on the OpenGL redbook Appendix Session "Floating-Point Formats Used in OpenGL". |
| emu->addEmulatedFunction(EOpPackHalf2x16, float2, |
| "#if !defined(GL_ARB_shading_language_packing)\n" |
| " uint webgl_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 webgl_packHalf2x16_emu(vec2 v)\n" |
| "{\n" |
| " #if defined(GL_ARB_shading_language_packing)\n" |
| " return packHalf2x16(v);\n" |
| " #else\n" |
| " uint x = webgl_f32tof16(v.x);\n" |
| " uint y = webgl_f32tof16(v.y);\n" |
| " return (y << 16) | x;\n" |
| " #endif\n" |
| "}\n"); |
| emu->addEmulatedFunction(EOpUnpackHalf2x16, uint1, |
| "#if !defined(GL_ARB_shading_language_packing)\n" |
| " float webgl_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" |
| " scale = 1.0 / (1 << -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 webgl_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(webgl_f16tof32(x), webgl_f16tof32(y));\n" |
| " #endif\n" |
| "}\n"); |
| // clang-format on |
| } |
| } |
