diff options
Diffstat (limited to 'mesalib/src/gallium/auxiliary/util/u_format_r11g11b10f.h')
| -rw-r--r-- | mesalib/src/gallium/auxiliary/util/u_format_r11g11b10f.h | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/mesalib/src/gallium/auxiliary/util/u_format_r11g11b10f.h b/mesalib/src/gallium/auxiliary/util/u_format_r11g11b10f.h new file mode 100644 index 000000000..e079b90b1 --- /dev/null +++ b/mesalib/src/gallium/auxiliary/util/u_format_r11g11b10f.h @@ -0,0 +1,190 @@ +/*
+ * Copyright (C) 2011 Marek Olšák <maraeo@gmail.com>
+ *
+ * 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_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_EXPONENT_BIAS 15
+#define UF10_EXPONENT_BITS 0x1F
+#define UF10_EXPONENT_SHIFT 5
+#define UF10_MANTISSA_BITS 0x3F
+#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)
+{
+ uint32_t f32 = (*(uint32_t *) &val);
+ uint16_t uf11 = 0;
+
+ /* Decode little-endian 32-bit floating-point value */
+ int sign = (f32 >> 16) & 0x8000;
+ /* Map exponent to the range [-127,128] */
+ int exponent = ((f32 >> 23) & 0xff) - 127;
+ int mantissa = f32 & 0x007fffff;
+
+ if (sign) return 0;
+
+ if (exponent == 128) { /* Infinity or NaN */
+ uf11 = UF11_MAX_EXPONENT;
+ if (mantissa) uf11 |= (mantissa & UF11_MANTISSA_BITS);
+ }
+ else if (exponent > 15) { /* Overflow - flush to Infinity */
+ uf11 = UF11_MAX_EXPONENT;
+ }
+ 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 = 1.0 / (1 << -exponent);
+ }
+ else {
+ scale = 1 << exponent;
+ }
+ decimal = 1.0 + (float) mantissa / 64;
+ f32.f = scale * decimal;
+ }
+
+ return f32.f;
+}
+
+static INLINE unsigned f32_to_uf10(float val)
+{
+ uint32_t f32 = (*(uint32_t *) &val);
+ uint16_t uf10 = 0;
+
+ /* Decode little-endian 32-bit floating-point value */
+ int sign = (f32 >> 16) & 0x8000;
+ /* Map exponent to the range [-127,128] */
+ int exponent = ((f32 >> 23) & 0xff) - 127;
+ int mantissa = f32 & 0x007fffff;
+
+ if (sign) return 0;
+
+ if (exponent == 128) { /* Infinity or NaN */
+ uf10 = UF10_MAX_EXPONENT;
+ if (mantissa) uf10 |= (mantissa & UF10_MANTISSA_BITS);
+ }
+ else if (exponent > 15) { /* Overflow - flush to Infinity */
+ uf10 = UF10_MAX_EXPONENT;
+ }
+ 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 & 0x07c0) >> UF10_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 = 1.0 / (1 << -exponent);
+ }
+ else {
+ scale = 1 << exponent;
+ }
+ decimal = 1.0 + (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);
+}
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