// // 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 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 } }