From 638342858894293246400d95a90d153c7f66719a Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Tue, 25 May 2010 11:45:05 -0700
Subject: i965: Add support for GL_ALPHA framebuffer objects.

---
 src/mesa/drivers/dri/common/spantmp2.h | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

(limited to 'src/mesa/drivers/dri/common')

diff --git a/src/mesa/drivers/dri/common/spantmp2.h b/src/mesa/drivers/dri/common/spantmp2.h
index 98422a85647..1dab7336b9b 100644
--- a/src/mesa/drivers/dri/common/spantmp2.h
+++ b/src/mesa/drivers/dri/common/spantmp2.h
@@ -413,6 +413,38 @@
      } while (0)
 # endif
 
+#elif (SPANTMP_PIXEL_FMT == GL_ALPHA) && (SPANTMP_PIXEL_TYPE == GL_UNSIGNED_BYTE)
+
+/**
+ ** GL_ALPHA, GL_UNSIGNED_BYTE
+ **/
+
+#ifndef GET_VALUE
+#ifndef GET_PTR
+#define GET_PTR(_x, _y) (     buf + (_x) + (_y) * pitch)
+#endif
+
+#define GET_VALUE(_x, _y) *(volatile GLubyte *)(GET_PTR(_x, _y))
+#define PUT_VALUE(_x, _y, _v) *(volatile GLubyte *)(GET_PTR(_x, _y)) = (_v)
+#endif /* GET_VALUE */
+
+# define INIT_MONO_PIXEL(p, color)                       \
+     p = color[3]
+
+# define WRITE_RGBA(_x, _y, r, g, b, a)                                 \
+   PUT_VALUE(_x, _y, a | (r & 0 /* quiet warnings */))
+
+#define WRITE_PIXEL(_x, _y, p) PUT_VALUE(_x, _y, p)
+
+#define READ_RGBA( rgba, _x, _y )				        \
+     do {								\
+        GLubyte p = GET_VALUE(_x, _y);					\
+	rgba[0] = 0;							\
+	rgba[1] = 0;							\
+	rgba[2] = 0;							\
+	rgba[3] = p;							\
+     } while (0)
+
 #else
 #error SPANTMP_PIXEL_FMT must be set to a valid value!
 #endif
-- 
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