[Mesa-dev] [PATCH] vbo: Correctly handle attribute offsets in dlist draw.

[Mathias.Froehlich at gmx.net]

From: Mathias Fröhlich <mathias.froehlich at web.de>

Hi,

I found the below while fixing a similar problem lately in
the immediate mode glBegin/glEnd code path.

Please review
Thanks

Mathias



When executing a display list draw with a shader program
using the generic0 attribute the offset computation
may get out of sync. To fix precompute the offsets
on the full attribute list and store the offsets in
the display list node.

Signed-off-by: Mathias Fröhlich <Mathias.Froehlich at web.de>
---
 src/mesa/vbo/vbo_save.h      |  1 +
 src/mesa/vbo/vbo_save_api.c  |  6 ++++++
 src/mesa/vbo/vbo_save_draw.c | 35 +++++++++++++++++------------------
 3 files changed, 24 insertions(+), 18 deletions(-)

diff --git a/src/mesa/vbo/vbo_save.h b/src/mesa/vbo/vbo_save.h
index 2843b3c..a61973f 100644
--- a/src/mesa/vbo/vbo_save.h
+++ b/src/mesa/vbo/vbo_save.h
@@ -64,6 +64,7 @@ struct vbo_save_vertex_list {
    GLbitfield64 enabled; /**< mask of enabled vbo arrays. */
    GLubyte attrsz[VBO_ATTRIB_MAX];
    GLenum attrtype[VBO_ATTRIB_MAX];
+   GLushort offsets[VBO_ATTRIB_MAX];
    GLuint vertex_size;  /**< size in GLfloats */
 
    /* Copy of the final vertex from node->vertex_store->bufferobj.
diff --git a/src/mesa/vbo/vbo_save_api.c b/src/mesa/vbo/vbo_save_api.c
index f648ccc..4473fef 100644
--- a/src/mesa/vbo/vbo_save_api.c
+++ b/src/mesa/vbo/vbo_save_api.c
@@ -436,6 +436,12 @@ _save_compile_vertex_list(struct gl_context *ctx)
    node->vertex_size = save->vertex_size;
    node->buffer_offset =
       (save->buffer - save->vertex_store->buffer) * sizeof(GLfloat);
+   GLushort offset = 0;
+   int i;
+   for (i = 0; i < VBO_ATTRIB_MAX; ++i) {
+      node->offsets[i] = offset;
+      offset += node->attrsz[i] * sizeof(GLfloat);
+   }
    node->count = save->vert_count;
    node->wrap_count = save->copied.nr;
    node->dangling_attr_ref = save->dangling_attr_ref;
diff --git a/src/mesa/vbo/vbo_save_draw.c b/src/mesa/vbo/vbo_save_draw.c
index 507ab82..e69c108 100644
--- a/src/mesa/vbo/vbo_save_draw.c
+++ b/src/mesa/vbo/vbo_save_draw.c
@@ -26,6 +26,7 @@
  *    Keith Whitwell <keithw at vmware.com>
  */
 
+#include <stdbool.h>
 #include "main/glheader.h"
 #include "main/bufferobj.h"
 #include "main/context.h"
@@ -136,15 +137,10 @@ static void vbo_bind_vertex_list(struct gl_context *ctx,
    struct vbo_context *vbo = vbo_context(ctx);
    struct vbo_save_context *save = &vbo->save;
    struct gl_client_array *arrays = save->arrays;
-   GLuint buffer_offset = node->buffer_offset;
    const GLuint *map;
    GLuint attr;
-   GLubyte node_attrsz[VBO_ATTRIB_MAX];  /* copy of node->attrsz[] */
-   GLenum node_attrtype[VBO_ATTRIB_MAX];  /* copy of node->attrtype[] */
    GLbitfield64 varying_inputs = 0x0;
-
-   memcpy(node_attrsz, node->attrsz, sizeof(node->attrsz));
-   memcpy(node_attrtype, node->attrtype, sizeof(node->attrtype));
+   bool generic_from_pos = false;
 
    /* Install the default (ie Current) attributes first, then overlay
     * all active ones.
@@ -176,10 +172,7 @@ static void vbo_bind_vertex_list(struct gl_context *ctx,
        */
       if ((ctx->VertexProgram._Current->Base.InputsRead & VERT_BIT_POS) == 0 &&
           (ctx->VertexProgram._Current->Base.InputsRead & VERT_BIT_GENERIC0)) {
-         save->inputs[VERT_ATTRIB_GENERIC0] = save->inputs[0];
-         node_attrsz[VERT_ATTRIB_GENERIC0] = node_attrsz[0];
-         node_attrtype[VERT_ATTRIB_GENERIC0] = node_attrtype[0];
-         node_attrsz[0] = 0;
+         generic_from_pos = true;
       }
       break;
    default:
@@ -188,30 +181,36 @@ static void vbo_bind_vertex_list(struct gl_context *ctx,
 
    for (attr = 0; attr < VERT_ATTRIB_MAX; attr++) {
       const GLuint src = map[attr];
+      const GLubyte size = node->attrsz[src];
 
-      if (node_attrsz[src]) {
+      if (size) {
          /* override the default array set above */
          save->inputs[attr] = &arrays[attr];
 
-	 arrays[attr].Ptr = (const GLubyte *) NULL + buffer_offset;
-	 arrays[attr].Size = node_attrsz[src];
+         const uintptr_t buffer_offset = node->buffer_offset;
+         arrays[attr].Ptr = ADD_POINTERS(buffer_offset, node->offsets[src]);
+         arrays[attr].Size = size;
 	 arrays[attr].StrideB = node->vertex_size * sizeof(GLfloat);
-         arrays[attr].Type = node_attrtype[src];
-         arrays[attr].Integer =
-               vbo_attrtype_to_integer_flag(node_attrtype[src]);
+         const GLenum type = node->attrtype[src];
+         arrays[attr].Type = type;
+         arrays[attr].Integer = vbo_attrtype_to_integer_flag(type);
          arrays[attr].Format = GL_RGBA;
-         arrays[attr]._ElementSize = arrays[attr].Size * sizeof(GLfloat);
+         arrays[attr]._ElementSize = size * sizeof(GLfloat);
          _mesa_reference_buffer_object(ctx,
                                        &arrays[attr].BufferObj,
                                        node->vertex_store->bufferobj);
 	 
 	 assert(arrays[attr].BufferObj->Name);
 
-	 buffer_offset += node_attrsz[src] * sizeof(GLfloat);
          varying_inputs |= VERT_BIT(attr);
       }
    }
 
+   if (generic_from_pos) {
+      varying_inputs |= (varying_inputs & VERT_BIT_POS) << VERT_ATTRIB_GENERIC0;
+      save->inputs[VERT_ATTRIB_GENERIC0] = save->inputs[VERT_ATTRIB_POS];
+   }
+
    _mesa_set_varying_vp_inputs( ctx, varying_inputs );
    ctx->NewDriverState |= ctx->DriverFlags.NewArray;
 }
-- 
2.7.4