From 3c9df0bda67cdcbc340a4f20997f7a3345cbe9cb Mon Sep 17 00:00:00 2001
From: Christoph Bumiller <e0425955@student.tuwien.ac.at>
Date: Tue, 20 Apr 2010 21:18:15 +0200
Subject: [PATCH] nv50: support vertex index bias

---
 src/gallium/drivers/nv50/nv50_push.c | 39 +++++++++++++++++++++++++---
 src/gallium/drivers/nv50/nv50_vbo.c  |  9 ++++---
 2 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/src/gallium/drivers/nv50/nv50_push.c b/src/gallium/drivers/nv50/nv50_push.c
index c54fed5a36f..244242b8434 100644
--- a/src/gallium/drivers/nv50/nv50_push.c
+++ b/src/gallium/drivers/nv50/nv50_push.c
@@ -13,6 +13,7 @@ struct push_context {
    unsigned vtx_size;
 
    void *idxbuf;
+   int32_t idxbias;
    unsigned idxsize;
 
    float edgeflag;
@@ -143,6 +144,16 @@ emit_elt08(void *priv, unsigned start, unsigned count)
       emit_vertex(ctx, idxbuf[start++]);
 }
 
+static void
+emit_elt08_biased(void *priv, unsigned start, unsigned count)
+{
+   struct push_context *ctx = priv;
+   uint8_t *idxbuf = ctx->idxbuf;
+
+   while (count--)
+      emit_vertex(ctx, idxbuf[start++] + ctx->idxbias);
+}
+
 static void
 emit_elt16(void *priv, unsigned start, unsigned count)
 {
@@ -153,6 +164,16 @@ emit_elt16(void *priv, unsigned start, unsigned count)
       emit_vertex(ctx, idxbuf[start++]);
 }
 
+static void
+emit_elt16_biased(void *priv, unsigned start, unsigned count)
+{
+   struct push_context *ctx = priv;
+   uint16_t *idxbuf = ctx->idxbuf;
+
+   while (count--)
+      emit_vertex(ctx, idxbuf[start++] + ctx->idxbias);
+}
+
 static void
 emit_elt32(void *priv, unsigned start, unsigned count)
 {
@@ -163,6 +184,16 @@ emit_elt32(void *priv, unsigned start, unsigned count)
       emit_vertex(ctx, idxbuf[start++]);
 }
 
+static void
+emit_elt32_biased(void *priv, unsigned start, unsigned count)
+{
+   struct push_context *ctx = priv;
+   uint32_t *idxbuf = ctx->idxbuf;
+
+   while (count--)
+      emit_vertex(ctx, idxbuf[start++] + ctx->idxbias);
+}
+
 static void
 emit_verts(void *priv, unsigned start, unsigned count)
 {
@@ -269,8 +300,8 @@ nv50_push_elements_instanced(struct pipe_context *pipe,
          return;
       }
       ctx.idxbuf = bo->map;
+      ctx.idxbias = idxbias;
       ctx.idxsize = idxsize;
-      assert(idxbias == 0);
       nouveau_bo_unmap(bo);
    }
 
@@ -278,12 +309,12 @@ nv50_push_elements_instanced(struct pipe_context *pipe,
    s.edge = emit_edgeflag;
    if (idxbuf) {
       if (idxsize == 1)
-         s.emit = emit_elt08;
+         s.emit = idxbias ? emit_elt08_biased : emit_elt08;
       else
       if (idxsize == 2)
-         s.emit = emit_elt16;
+         s.emit = idxbias ? emit_elt16_biased : emit_elt16;
       else
-         s.emit = emit_elt32;
+         s.emit = idxbias ? emit_elt32_biased : emit_elt32;
    } else
       s.emit = emit_verts;
 
diff --git a/src/gallium/drivers/nv50/nv50_vbo.c b/src/gallium/drivers/nv50/nv50_vbo.c
index 911eabca1cf..34719c956a0 100644
--- a/src/gallium/drivers/nv50/nv50_vbo.c
+++ b/src/gallium/drivers/nv50/nv50_vbo.c
@@ -401,14 +401,17 @@ nv50_draw_elements_instanced(struct pipe_context *pipe,
 	if (!nv50_state_validate(nv50, 13 + 16*3))
 		return;
 
-	assert(indexBias == 0);
-
 	if (nv50->vbo_fifo) {
 		nv50_push_elements_instanced(pipe, indexBuffer, indexSize,
 					     indexBias, mode, start, count,
 					     startInstance, instanceCount);
 		return;
-	} else
+	}
+
+	/* indices are uint32 internally, so large indexBias means negative */
+	BEGIN_RING(chan, tesla, NV50TCL_VB_ELEMENT_BASE, 1);
+	OUT_RING  (chan, indexBias);
+
 	if (!(indexBuffer->bind & PIPE_BIND_INDEX_BUFFER) || indexSize == 1) {
 		nv50_draw_elements_inline(pipe, indexBuffer, indexSize,
 					  mode, start, count, startInstance,
-- 
2.30.2