st/nine: Implement dummy vbo behaviour when vs is missing inputs

Use a dummy vertex buffer object when vs inputs have no corresponding
entries in the vertex declaration. This dummy buffer will give to the
shader float4(0,0,0,0).

This fixes several artifacts on some games.

Signed-off-by: Axel Davy <[email protected]>
Signed-off-by: Tiziano Bacocco <[email protected]>

1 files changed, 37 insertions, 0 deletions

diff --git a/src/gallium/state_trackers/nine/device9.c b/src/gallium/state_trackers/nine/device9.c
index e0524644f8a..78e148bca77 100644
--- a/src/gallium/state_trackers/nine/device9.c
+++ b/src/gallium/state_trackers/nine/device9.c
@@ -221,6 +221,42 @@ NineDevice9_ctor( struct NineDevice9 *This,
         NineUnknown_ConvertRefToBind(NineUnknown(This->state.rt[i]));
     }
 
+    /* Initialize a dummy VBO to be used when a a vertex declaration does not
+     * specify all the inputs needed by vertex shader, on win default behavior
+     * is to pass 0,0,0,0 to the shader */
+    {
+        struct pipe_transfer *transfer;
+        struct pipe_resource tmpl;
+        struct pipe_box box;
+        unsigned char *data;
+
+        tmpl.target = PIPE_BUFFER;
+        tmpl.format = PIPE_FORMAT_R8_UNORM;
+        tmpl.width0 = 16; /* 4 floats */
+        tmpl.height0 = 1;
+        tmpl.depth0 = 1;
+        tmpl.array_size = 1;
+        tmpl.last_level = 0;
+        tmpl.nr_samples = 0;
+        tmpl.usage = PIPE_USAGE_DEFAULT;
+        tmpl.bind = PIPE_BIND_VERTEX_BUFFER | PIPE_BIND_TRANSFER_WRITE;
+        tmpl.flags = 0;
+        This->dummy_vbo = pScreen->resource_create(pScreen, &tmpl);
+
+        if (!This->dummy_vbo)
+            return D3DERR_OUTOFVIDEOMEMORY;
+
+        u_box_1d(0, 16, &box);
+        data = This->pipe->transfer_map(This->pipe, This->dummy_vbo, 0,
+                                        PIPE_TRANSFER_WRITE |
+                                        PIPE_TRANSFER_DISCARD_WHOLE_RESOURCE,
+                                        &box, &transfer);
+        assert(data);
+        assert(transfer);
+        memset(data, 0, 16);
+        This->pipe->transfer_unmap(This->pipe, transfer);
+    }
+
     This->cursor.software = FALSE;
     This->cursor.hotspot.x = -1;
     This->cursor.hotspot.y = -1;
@@ -387,6 +423,7 @@ NineDevice9_dtor( struct NineDevice9 *This )
     pipe_resource_reference(&This->dummy_texture, NULL);
     pipe_resource_reference(&This->constbuf_vs, NULL);
     pipe_resource_reference(&This->constbuf_ps, NULL);
+    pipe_resource_reference(&This->dummy_vbo, NULL);
     FREE(This->state.vs_const_f);
     FREE(This->state.ps_const_f);
     FREE(This->state.vs_lconstf_temp);