diff options
Diffstat (limited to 'src/util')
| -rw-r--r-- | src/util/Makefile.sources | 1 | ||||
| -rw-r--r-- | src/util/format_r11g11b10f.h | 232 |
2 files changed, 233 insertions, 0 deletions
diff --git a/src/util/Makefile.sources b/src/util/Makefile.sources index 6bf01437a8b..6def4f7c561 100644 --- a/src/util/Makefile.sources +++ b/src/util/Makefile.sources @@ -4,6 +4,7 @@ MESA_UTIL_FILES := \ bitset.h \ debug.c \ debug.h \ + format_r11g11b10f.h \ format_rgb9e5.h \ format_srgb.h \ half_float.c \ diff --git a/src/util/format_r11g11b10f.h b/src/util/format_r11g11b10f.h new file mode 100644 index 00000000000..218822b16e6 --- /dev/null +++ b/src/util/format_r11g11b10f.h @@ -0,0 +1,232 @@ +/* + * Copyright (C) 2011 Marek Olšák <[email protected]> + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + */ + +/* Based on code from The OpenGL Programming Guide / 7th Edition, Appendix J. + * Available here: http://www.opengl-redbook.com/appendices/ + * The algorithm in the book contains a bug though, which is fixed in the code + * below. + */ + +#define UF11(e, m) ((e << 6) | (m)) +#define UF11_EXPONENT_BIAS 15 +#define UF11_EXPONENT_BITS 0x1F +#define UF11_EXPONENT_SHIFT 6 +#define UF11_MANTISSA_BITS 0x3F +#define UF11_MANTISSA_SHIFT (23 - UF11_EXPONENT_SHIFT) +#define UF11_MAX_EXPONENT (UF11_EXPONENT_BITS << UF11_EXPONENT_SHIFT) + +#define UF10(e, m) ((e << 5) | (m)) +#define UF10_EXPONENT_BIAS 15 +#define UF10_EXPONENT_BITS 0x1F +#define UF10_EXPONENT_SHIFT 5 +#define UF10_MANTISSA_BITS 0x1F +#define UF10_MANTISSA_SHIFT (23 - UF10_EXPONENT_SHIFT) +#define UF10_MAX_EXPONENT (UF10_EXPONENT_BITS << UF10_EXPONENT_SHIFT) + +#define F32_INFINITY 0x7f800000 + +static inline unsigned f32_to_uf11(float val) +{ + union { + float f; + uint32_t ui; + } f32 = {val}; + + uint16_t uf11 = 0; + + /* Decode little-endian 32-bit floating-point value */ + int sign = (f32.ui >> 16) & 0x8000; + /* Map exponent to the range [-127,128] */ + int exponent = ((f32.ui >> 23) & 0xff) - 127; + int mantissa = f32.ui & 0x007fffff; + + if (exponent == 128) { /* Infinity or NaN */ + /* From the GL_EXT_packed_float spec: + * + * "Additionally: negative infinity is converted to zero; positive + * infinity is converted to positive infinity; and both positive and + * negative NaN are converted to positive NaN." + */ + uf11 = UF11_MAX_EXPONENT; + if (mantissa) { + uf11 |= 1; /* NaN */ + } else { + if (sign) + uf11 = 0; /* 0.0 */ + } + } else if (sign) { + return 0; + } else if (val > 65024.0f) { + /* From the GL_EXT_packed_float spec: + * + * "Likewise, finite positive values greater than 65024 (the maximum + * finite representable unsigned 11-bit floating-point value) are + * converted to 65024." + */ + uf11 = UF11(30, 63); + } + else if (exponent > -15) { /* Representable value */ + exponent += UF11_EXPONENT_BIAS; + mantissa >>= UF11_MANTISSA_SHIFT; + uf11 = exponent << UF11_EXPONENT_SHIFT | mantissa; + } + + return uf11; +} + +static inline float uf11_to_f32(uint16_t val) +{ + union { + float f; + uint32_t ui; + } f32; + + int exponent = (val & 0x07c0) >> UF11_EXPONENT_SHIFT; + int mantissa = (val & 0x003f); + + f32.f = 0.0; + + if (exponent == 0) { + if (mantissa != 0) { + const float scale = 1.0 / (1 << 20); + f32.f = scale * mantissa; + } + } + else if (exponent == 31) { + f32.ui = F32_INFINITY | mantissa; + } + else { + float scale, decimal; + exponent -= 15; + if (exponent < 0) { + scale = 1.0f / (1 << -exponent); + } + else { + scale = (float) (1 << exponent); + } + decimal = 1.0f + (float) mantissa / 64; + f32.f = scale * decimal; + } + + return f32.f; +} + +static inline unsigned f32_to_uf10(float val) +{ + union { + float f; + uint32_t ui; + } f32 = {val}; + + uint16_t uf10 = 0; + + /* Decode little-endian 32-bit floating-point value */ + int sign = (f32.ui >> 16) & 0x8000; + /* Map exponent to the range [-127,128] */ + int exponent = ((f32.ui >> 23) & 0xff) - 127; + int mantissa = f32.ui & 0x007fffff; + + if (exponent == 128) { + /* From the GL_EXT_packed_float spec: + * + * "Additionally: negative infinity is converted to zero; positive + * infinity is converted to positive infinity; and both positive and + * negative NaN are converted to positive NaN." + */ + uf10 = UF10_MAX_EXPONENT; + if (mantissa) { + uf10 |= 1; /* NaN */ + } else { + if (sign) + uf10 = 0; /* 0.0 */ + } + } else if (sign) { + return 0; + } else if (val > 64512.0f) { + /* From the GL_EXT_packed_float spec: + * + * "Likewise, finite positive values greater than 64512 (the maximum + * finite representable unsigned 10-bit floating-point value) are + * converted to 64512." + */ + uf10 = UF10(30, 31); + } + else if (exponent > -15) { /* Representable value */ + exponent += UF10_EXPONENT_BIAS; + mantissa >>= UF10_MANTISSA_SHIFT; + uf10 = exponent << UF10_EXPONENT_SHIFT | mantissa; + } + + return uf10; +} + +static inline float uf10_to_f32(uint16_t val) +{ + union { + float f; + uint32_t ui; + } f32; + + int exponent = (val & 0x03e0) >> UF10_EXPONENT_SHIFT; + int mantissa = (val & 0x001f); + + f32.f = 0.0; + + if (exponent == 0) { + if (mantissa != 0) { + const float scale = 1.0 / (1 << 20); + f32.f = scale * mantissa; + } + } + else if (exponent == 31) { + f32.ui = F32_INFINITY | mantissa; + } + else { + float scale, decimal; + exponent -= 15; + if (exponent < 0) { + scale = 1.0f / (1 << -exponent); + } + else { + scale = (float) (1 << exponent); + } + decimal = 1.0f + (float) mantissa / 32; + f32.f = scale * decimal; + } + + return f32.f; +} + +static inline unsigned float3_to_r11g11b10f(const float rgb[3]) +{ + return ( f32_to_uf11(rgb[0]) & 0x7ff) | + ((f32_to_uf11(rgb[1]) & 0x7ff) << 11) | + ((f32_to_uf10(rgb[2]) & 0x3ff) << 22); +} + +static inline void r11g11b10f_to_float3(unsigned rgb, float retval[3]) +{ + retval[0] = uf11_to_f32( rgb & 0x7ff); + retval[1] = uf11_to_f32((rgb >> 11) & 0x7ff); + retval[2] = uf10_to_f32((rgb >> 22) & 0x3ff); +} |