mesa: move glMultiDrawArrays to vbo and fix error handling

When any count[i] is negative, we must skip all draws.

Moving to vbo makes the subsequent change easier.

v2:
- provide the function in all contexts, including GLES
- adjust validation accordingly to include the xfb check
v3:
- fix mix-up of pre- and post-xfb prim count (Nils Wallménius)

Cc: [email protected]
Reviewed-by: Timothy Arceri <[email protected]>
Reviewed-by: Marek Olšák <[email protected]>

3 files changed, 58 insertions, 18 deletions

diff --git a/src/mesa/main/api_validate.c b/src/mesa/main/api_validate.c
index 2e1829bb13a..e23be60b2b4 100644
--- a/src/mesa/main/api_validate.c
+++ b/src/mesa/main/api_validate.c
@@ -921,6 +921,60 @@ _mesa_validate_DrawArraysInstanced(struct gl_context *ctx, GLenum mode, GLint fi
 }
 
 
+/**
+ * Called to error check the function parameters.
+ *
+ * Note that glMultiDrawArrays is not part of GLES, so there's limited scope
+ * for sharing code with the validation of glDrawArrays.
+ */
+bool
+_mesa_validate_MultiDrawArrays(struct gl_context *ctx, GLenum mode,
+                               const GLsizei *count, GLsizei primcount)
+{
+   int i;
+
+   FLUSH_CURRENT(ctx, 0);
+
+   if (!_mesa_valid_prim_mode(ctx, mode, "glMultiDrawArrays"))
+      return false;
+
+   if (!check_valid_to_render(ctx, "glMultiDrawArrays"))
+      return false;
+
+   if (primcount < 0) {
+      _mesa_error(ctx, GL_INVALID_VALUE, "glMultiDrawArrays(primcount=%d)",
+                  primcount);
+      return false;
+   }
+
+   for (i = 0; i < primcount; ++i) {
+      if (count[i] < 0) {
+         _mesa_error(ctx, GL_INVALID_VALUE, "glMultiDrawArrays(count[%d]=%d)",
+                     i, count[i]);
+         return false;
+      }
+   }
+
+   if (need_xfb_remaining_prims_check(ctx)) {
+      struct gl_transform_feedback_object *xfb_obj
+         = ctx->TransformFeedback.CurrentObject;
+      size_t xfb_prim_count = 0;
+
+      for (i = 0; i < primcount; ++i)
+         xfb_prim_count += vbo_count_tessellated_primitives(mode, count[i], 1);
+
+      if (xfb_obj->GlesRemainingPrims < xfb_prim_count) {
+         _mesa_error(ctx, GL_INVALID_OPERATION,
+                     "glMultiDrawArrays(exceeds transform feedback size)");
+         return false;
+      }
+      xfb_obj->GlesRemainingPrims -= xfb_prim_count;
+   }
+
+   return true;
+}
+
+
 GLboolean
 _mesa_validate_DrawElementsInstanced(struct gl_context *ctx,
                                      GLenum mode, GLsizei count, GLenum type,
diff --git a/src/mesa/main/api_validate.h b/src/mesa/main/api_validate.h
index de520c98dcb..93ec93d7bcb 100644
--- a/src/mesa/main/api_validate.h
+++ b/src/mesa/main/api_validate.h
@@ -48,6 +48,10 @@ _mesa_valid_prim_mode(struct gl_context *ctx, GLenum mode, const char *name);
 extern GLboolean
 _mesa_validate_DrawArrays(struct gl_context *ctx, GLenum mode, GLsizei count);
 
+extern bool
+_mesa_validate_MultiDrawArrays(struct gl_context *ctx, GLenum mode,
+                               const GLsizei *count, GLsizei primcount);
+
 extern GLboolean
 _mesa_validate_DrawElements(struct gl_context *ctx,
 			    GLenum mode, GLsizei count, GLenum type,
diff --git a/src/mesa/main/varray.c b/src/mesa/main/varray.c
index 233dc0dc419..205498501a3 100644
--- a/src/mesa/main/varray.c
+++ b/src/mesa/main/varray.c
@@ -1539,24 +1539,6 @@ _mesa_UnlockArraysEXT( void )
 }
 
 
-/* GL_EXT_multi_draw_arrays */
-void GLAPIENTRY
-_mesa_MultiDrawArrays( GLenum mode, const GLint *first,
-                          const GLsizei *count, GLsizei primcount )
-{
-   GET_CURRENT_CONTEXT(ctx);
-   GLint i;
-
-   FLUSH_VERTICES(ctx, 0);
-
-   for (i = 0; i < primcount; i++) {
-      if (count[i] > 0) {
-         CALL_DrawArrays(ctx->CurrentClientDispatch, (mode, first[i], count[i]));
-      }
-   }
-}
-
-
 /* GL_IBM_multimode_draw_arrays */
 void GLAPIENTRY
 _mesa_MultiModeDrawArraysIBM( const GLenum * mode, const GLint * first,