mesa: add new signed rgba texture format

This is a (partial) backport of the signed texture format support in OGL 3.1.
Since it wasn't promoted from an existing extension roll our own.

1 files changed, 22 insertions, 0 deletions

diff --git a/src/mesa/main/macros.h b/src/mesa/main/macros.h
index bfd740870e..01d59dd42d 100644
--- a/src/mesa/main/macros.h
+++ b/src/mesa/main/macros.h
@@ -54,12 +54,20 @@ extern GLfloat _mesa_ubyte_to_float_color_tab[256];
 #define FLOAT_TO_BYTE(X)    ( (((GLint) (255.0F * (X))) - 1) / 2 )
 
 
+/** Convert GLbyte in [-128,127] to GLfloat in [-1.0,1.0], texture/fb data */
+#define BYTE_TO_FLOAT_TEX(B)    ((B) == -128 ? -1.0 : (B) * (1.0F/127.0F))
+
+/** Convert GLfloat in [-1.0,1.0] to GLbyte in [-128,127], texture/fb data */
+#define FLOAT_TO_BYTE_TEX(X)    ( (GLint) (127.0F * (X)) )
+
+
 /** Convert GLushort in [0,65535] to GLfloat in [0.0,1.0] */
 #define USHORT_TO_FLOAT(S)  ((GLfloat) (S) * (1.0F / 65535.0F))
 
 /** Convert GLfloat in [0.0,1.0] to GLushort in [0, 65535] */
 #define FLOAT_TO_USHORT(X)   ((GLuint) ((X) * 65535.0))
 
+
 /** Convert GLshort in [-32768,32767] to GLfloat in [-1.0,1.0] */
 #define SHORT_TO_FLOAT(S)   ((2.0F * (S) + 1.0F) * (1.0F/65535.0F))
 
@@ -67,6 +75,13 @@ extern GLfloat _mesa_ubyte_to_float_color_tab[256];
 #define FLOAT_TO_SHORT(X)   ( (((GLint) (65535.0F * (X))) - 1) / 2 )
 
 
+/** Convert GLshort in [-32768,32767] to GLfloat in [-1.0,1.0], texture/fb data */
+#define SHORT_TO_FLOAT_TEX(S)    ((S) == -32768 ? -1.0 : (S) * (1.0F/32767.0F))
+
+/** Convert GLfloat in [-1.0,1.0] to GLshort in [-32768,32767], texture/fb data */
+#define FLOAT_TO_SHORT_TEX(X)    ( (GLint) (32767.0F * (X)) )
+
+
 /** Convert GLuint in [0,4294967295] to GLfloat in [0.0,1.0] */
 #define UINT_TO_FLOAT(U)    ((GLfloat) (U) * (1.0F / 4294967295.0F))
 
@@ -85,6 +100,13 @@ extern GLfloat _mesa_ubyte_to_float_color_tab[256];
 #define FLOAT_TO_INT(X)     ( (GLint) (2147483647.0 * (X)) )
 
 
+/** Convert GLint in [-2147483648,2147483647] to GLfloat in [-1.0,1.0], texture/fb data */
+#define INT_TO_FLOAT_TEX(I)    ((I) == -2147483648 ? -1.0 : (I) * (1.0F/2147483647.0))
+
+/** Convert GLfloat in [-1.0,1.0] to GLint in [-2147483648,2147483647], texture/fb data */
+#define FLOAT_TO_INT_TEX(X)    ( (GLint) (2147483647.0F * (X)) )
+
+
 #define BYTE_TO_UBYTE(b)   ((GLubyte) ((b) < 0 ? 0 : (GLubyte) (b)))
 #define SHORT_TO_UBYTE(s)  ((GLubyte) ((s) < 0 ? 0 : (GLubyte) ((s) >> 7)))
 #define USHORT_TO_UBYTE(s) ((GLubyte) ((s) >> 8))