r300g: implement MSAA

[mesa.git] / src / gallium / auxiliary / util / u_format_r11g11b10f.h

diff --git a/src/gallium/auxiliary/util/u_format_r11g11b10f.h b/src/gallium/auxiliary/util/u_format_r11g11b10f.h
index c4181d0e34eb9a075e7e71395a710e9b1504d29b..b883b318e03601f5cbfa68fb6644445f5a42167d 100644 (file)
--- a/src/gallium/auxiliary/util/u_format_r11g11b10f.h
+++ b/src/gallium/auxiliary/util/u_format_r11g11b10f.h
@@ -27,6 +27,7 @@
  * below.
  */
 
+#define UF11(e, m)           ((e << 6) | (m))
 #define UF11_EXPONENT_BIAS   15
 #define UF11_EXPONENT_BITS   0x1F
 #define UF11_EXPONENT_SHIFT  6
@@ -34,10 +35,11 @@
 #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   0x3F
+#define UF10_MANTISSA_BITS   0x1F
 #define UF10_MANTISSA_SHIFT  (23 - UF10_EXPONENT_SHIFT)
 #define UF10_MAX_EXPONENT    (UF10_EXPONENT_BITS << UF10_EXPONENT_SHIFT)
 
@@ -45,23 +47,43 @@
 
 static INLINE unsigned f32_to_uf11(float val)
 {
-   uint32_t f32 = (*(uint32_t *) &val);
+   union {
+      float f;
+      uint32_t ui;
+   } f32 = {val};
+
    uint16_t uf11 = 0;
 
    /* Decode little-endian 32-bit floating-point value */
-   int sign = (f32 >> 16) & 0x8000;
+   int sign = (f32.ui >> 16) & 0x8000;
    /* Map exponent to the range [-127,128] */
-   int exponent = ((f32 >> 23) & 0xff) - 127;
-   int mantissa = f32 & 0x007fffff;
-
-   if (sign) return 0;
+   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 |= (mantissa & UF11_MANTISSA_BITS);
-   }
-   else if (exponent > 15) { /* Overflow - flush to Infinity */
-      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;
@@ -97,12 +119,12 @@ static INLINE float uf11_to_f32(uint16_t val)
       float scale, decimal;
       exponent -= 15;
       if (exponent < 0) {
-         scale = 1.0 / (1 << -exponent);
+         scale = 1.0f / (1 << -exponent);
       }
       else {
-         scale = 1 << exponent;
+         scale = (float) (1 << exponent);
       }
-      decimal = 1.0 + (float) mantissa / 64;
+      decimal = 1.0f + (float) mantissa / 64;
       f32.f = scale * decimal;
    }
 
@@ -111,23 +133,43 @@ static INLINE float uf11_to_f32(uint16_t val)
 
 static INLINE unsigned f32_to_uf10(float val)
 {
-   uint32_t f32 = (*(uint32_t *) &val);
+   union {
+      float f;
+      uint32_t ui;
+   } f32 = {val};
+
    uint16_t uf10 = 0;
 
    /* Decode little-endian 32-bit floating-point value */
-   int sign = (f32 >> 16) & 0x8000;
+   int sign = (f32.ui >> 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 */
+   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) { /* Overflow - flush to Infinity */
+      /* 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;
@@ -145,8 +187,8 @@ static INLINE float uf10_to_f32(uint16_t val)
       uint32_t ui;
    } f32;
 
-   int exponent = (val & 0x07c0) >> UF10_EXPONENT_SHIFT;
-   int mantissa = (val & 0x003f);
+   int exponent = (val & 0x03e0) >> UF10_EXPONENT_SHIFT;
+   int mantissa = (val & 0x001f);
 
    f32.f = 0.0;
 
@@ -163,12 +205,12 @@ static INLINE float uf10_to_f32(uint16_t val)
       float scale, decimal;
       exponent -= 15;
       if (exponent < 0) {
-         scale = 1.0 / (1 << -exponent);
+         scale = 1.0f / (1 << -exponent);
       }
       else {
-         scale = 1 << exponent;
+         scale = (float) (1 << exponent);
       }
-      decimal = 1.0 + (float) mantissa / 32;
+      decimal = 1.0f + (float) mantissa / 32;
       f32.f = scale * decimal;
    }