r300: move some more function to generic

1 files changed, 45 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/radeon/common_context.h b/src/mesa/drivers/dri/radeon/common_context.h
index 2748c51a59..d6e15bc3b8 100644
--- a/src/mesa/drivers/dri/radeon/common_context.h
+++ b/src/mesa/drivers/dri/radeon/common_context.h
@@ -343,6 +343,51 @@ struct radeon_context {
 
 #define RADEON_CONTEXT(glctx) ((radeonContextPtr)(ctx->DriverCtx))
 
+/**
+ * This function takes a float and packs it into a uint32_t
+ */
+static INLINE uint32_t radeonPackFloat32(float fl)
+{
+	union {
+		float fl;
+		uint32_t u;
+	} u;
+
+	u.fl = fl;
+	return u.u;
+}
+
+/* This is probably wrong for some values, I need to test this
+ * some more.  Range checking would be a good idea also..
+ *
+ * But it works for most things.  I'll fix it later if someone
+ * else with a better clue doesn't
+ */
+static INLINE uint32_t radeonPackFloat24(float f)
+{
+	float mantissa;
+	int exponent;
+	uint32_t float24 = 0;
+
+	if (f == 0.0)
+		return 0;
+
+	mantissa = frexpf(f, &exponent);
+
+	/* Handle -ve */
+	if (mantissa < 0) {
+		float24 |= (1 << 23);
+		mantissa = mantissa * -1.0;
+	}
+	/* Handle exponent, bias of 63 */
+	exponent += 62;
+	float24 |= (exponent << 16);
+	/* Kill 7 LSB of mantissa */
+	float24 |= (radeonPackFloat32(mantissa) & 0x7FFFFF) >> 7;
+
+	return float24;
+}
+
 /* ================================================================
  * Debugging:
  */