texture format and sampler pt partial

hw/rtl/tex_unit/VX_tex_define.vh

@@ -23,4 +23,16 @@
 `define TEX_WRAP_CLAMP   1
 `define TEX_WRAP_MIRROR  2
 
+`define MAX_COLOR_WIDTH   8
+`define NUM_COLOR_CHANNEL 4  
+
+`define R5G6B5            `TEX_FORMAT_BITS'h1
+`define R8G8B8            `TEX_FORMAT_BITS'h2
+`define R8G8B8A8          `TEX_FORMAT_BITS'h3
+
+`define RBEGIN            24
+`define GBEGIN            16
+`define BBEGIN            8
+`define ABEGIN            0
+
 `endif