From: Oliver McFadden <z3ro.geek@gmail.com>
Date: Mon, 28 May 2007 01:11:54 +0000 (+0000)
Subject: r300: Document registers 0x2220 to 0x2230.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=97a89227b0edd3ef51d3ef9fd015bff12dc9b97b;p=mesa.git

r300: Document registers 0x2220 to 0x2230.

These registers are per-pixel and per-vertex X and Y clipping planes.
---

diff --git a/src/mesa/drivers/dri/r300/r300_cmdbuf.c b/src/mesa/drivers/dri/r300/r300_cmdbuf.c
index 0351989b2e4..0bc3be8880c 100644
--- a/src/mesa/drivers/dri/r300/r300_cmdbuf.c
+++ b/src/mesa/drivers/dri/r300/r300_cmdbuf.c
@@ -318,8 +318,8 @@ void r300InitCmdBuf(r300ContextPtr r300)
 	r300->hw.unk21DC.cmd[0] = cmdpacket0(0x21DC, 1);
 	ALLOC_STATE(unk221C, always, 2, 0);
 	r300->hw.unk221C.cmd[0] = cmdpacket0(R300_VAP_UNKNOWN_221C, 1);
-	ALLOC_STATE(unk2220, always, 5, 0);
-	r300->hw.unk2220.cmd[0] = cmdpacket0(0x2220, 4);
+	ALLOC_STATE(vap_clip, always, 5, 0);
+	r300->hw.vap_clip.cmd[0] = cmdpacket0(R300_VAP_CLIP_X_0, 4);
 	ALLOC_STATE(unk2288, always, 2, 0);
 	r300->hw.unk2288.cmd[0] = cmdpacket0(R300_VAP_UNKNOWN_2288, 1);
 	ALLOC_STATE(vof, always, R300_VOF_CMDSIZE, 0);
diff --git a/src/mesa/drivers/dri/r300/r300_context.h b/src/mesa/drivers/dri/r300/r300_context.h
index 6bd74fe9cd8..076bb49a006 100644
--- a/src/mesa/drivers/dri/r300/r300_context.h
+++ b/src/mesa/drivers/dri/r300/r300_context.h
@@ -452,7 +452,7 @@ struct r300_hw_state {
 	struct r300_state_atom vic;	/* vap input control (2180) */
 	struct r300_state_atom unk21DC;	/* (21DC) */
 	struct r300_state_atom unk221C;	/* (221C) */
-	struct r300_state_atom unk2220;	/* (2220) */
+	struct r300_state_atom vap_clip;
 	struct r300_state_atom unk2288;	/* (2288) */
 	struct r300_state_atom pvs;	/* pvs_cntl (22D0) */
 	struct r300_state_atom gb_enable;	/* (4008) */
diff --git a/src/mesa/drivers/dri/r300/r300_reg.h b/src/mesa/drivers/dri/r300/r300_reg.h
index 3f14dafc70a..6f0ed4d74ee 100644
--- a/src/mesa/drivers/dri/r300/r300_reg.h
+++ b/src/mesa/drivers/dri/r300/r300_reg.h
@@ -299,6 +299,16 @@ USE OR OTHER DEALINGS IN THE SOFTWARE.
 #       define R300_221C_NORMAL                  0x00000000
 #       define R300_221C_CLEAR                   0x0001C000
 
+/* These seem to be per-pixel and per-vertex X and Y clipping planes. The first
+ * plane is per-pixel and the second plane is per-vertex.
+ *
+ * This was determined by experimentation alone but I believe it is correct.
+ */
+#define R300_VAP_CLIP_X_0                   0x2220
+#define R300_VAP_CLIP_X_1                   0x2224
+#define R300_VAP_CLIP_Y_0                   0x2228
+#define R300_VAP_CLIP_Y_1                   0x2230
+
 /* gap */
 
 /* Sometimes, END_OF_PKT and 0x2284=0 are the only commands sent between
diff --git a/src/mesa/drivers/dri/r300/r300_state.c b/src/mesa/drivers/dri/r300/r300_state.c
index a9b20622e4c..38cf9d29a73 100644
--- a/src/mesa/drivers/dri/r300/r300_state.c
+++ b/src/mesa/drivers/dri/r300/r300_state.c
@@ -1882,10 +1882,10 @@ static void r300ResetHwState(r300ContextPtr r300)
 
 	r300->hw.unk221C.cmd[1] = R300_221C_NORMAL;
 
-	r300->hw.unk2220.cmd[1] = r300PackFloat32(1.0);
-	r300->hw.unk2220.cmd[2] = r300PackFloat32(1.0);
-	r300->hw.unk2220.cmd[3] = r300PackFloat32(1.0);
-	r300->hw.unk2220.cmd[4] = r300PackFloat32(1.0);
+	r300->hw.vap_clip.cmd[1] = r300PackFloat32(1.0); /* X */
+	r300->hw.vap_clip.cmd[2] = r300PackFloat32(1.0); /* X */
+	r300->hw.vap_clip.cmd[3] = r300PackFloat32(1.0); /* Y */
+	r300->hw.vap_clip.cmd[4] = r300PackFloat32(1.0); /* Y */
 
 	/* XXX: Other families? */
 	switch (r300->radeon.radeonScreen->chip_family) {