From 7b0d0a2bf2d147c6024ff1a4b1eaaad955e7d297 Mon Sep 17 00:00:00 2001
From: Iago Toral Quiroga <itoral@igalia.com>
Date: Thu, 19 Mar 2015 11:21:52 +0100
Subject: [PATCH] mesa: Implement _mesa_BindBuffersRange for target
 GL_SHADER_STORAGE_BUFFER

v2:
- Fix error message (Jordan)

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
---
 src/mesa/main/bufferobj.c | 110 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 110 insertions(+)

diff --git a/src/mesa/main/bufferobj.c b/src/mesa/main/bufferobj.c
index 27638caf9fc..0a9ffe41043 100644
--- a/src/mesa/main/bufferobj.c
+++ b/src/mesa/main/bufferobj.c
@@ -3579,6 +3579,112 @@ bind_uniform_buffers_range(struct gl_context *ctx, GLuint first, GLsizei count,
    _mesa_end_bufferobj_lookups(ctx);
 }
 
+static void
+bind_shader_storage_buffers_range(struct gl_context *ctx, GLuint first,
+                                  GLsizei count, const GLuint *buffers,
+                                  const GLintptr *offsets,
+                                  const GLsizeiptr *sizes)
+{
+   GLint i;
+
+   if (!error_check_bind_shader_storage_buffers(ctx, first, count,
+                                                "glBindBuffersRange"))
+      return;
+
+   /* Assume that at least one binding will be changed */
+   FLUSH_VERTICES(ctx, 0);
+   ctx->NewDriverState |= ctx->DriverFlags.NewShaderStorageBuffer;
+
+   if (!buffers) {
+      /* The ARB_multi_bind spec says:
+       *
+       *    "If <buffers> is NULL, all bindings from <first> through
+       *     <first>+<count>-1 are reset to their unbound (zero) state.
+       *     In this case, the offsets and sizes associated with the
+       *     binding points are set to default values, ignoring
+       *     <offsets> and <sizes>."
+       */
+      unbind_shader_storage_buffers(ctx, first, count);
+      return;
+   }
+
+   /* Note that the error semantics for multi-bind commands differ from
+    * those of other GL commands.
+    *
+    * The Issues section in the ARB_multi_bind spec says:
+    *
+    *    "(11) Typically, OpenGL specifies that if an error is generated by a
+    *          command, that command has no effect.  This is somewhat
+    *          unfortunate for multi-bind commands, because it would require a
+    *          first pass to scan the entire list of bound objects for errors
+    *          and then a second pass to actually perform the bindings.
+    *          Should we have different error semantics?
+    *
+    *       RESOLVED:  Yes.  In this specification, when the parameters for
+    *       one of the <count> binding points are invalid, that binding point
+    *       is not updated and an error will be generated.  However, other
+    *       binding points in the same command will be updated if their
+    *       parameters are valid and no other error occurs."
+    */
+
+   _mesa_begin_bufferobj_lookups(ctx);
+
+   for (i = 0; i < count; i++) {
+      struct gl_shader_storage_buffer_binding *binding =
+         &ctx->ShaderStorageBufferBindings[first + i];
+      struct gl_buffer_object *bufObj;
+
+      if (!bind_buffers_check_offset_and_size(ctx, i, offsets, sizes))
+         continue;
+
+      /* The ARB_multi_bind spec says:
+       *
+       *     "An INVALID_VALUE error is generated by BindBuffersRange if any
+       *      pair of values in <offsets> and <sizes> does not respectively
+       *      satisfy the constraints described for those parameters for the
+       *      specified target, as described in section 6.7.1 (per binding)."
+       *
+       * Section 6.7.1 refers to table 6.5, which says:
+       *
+       *     "┌───────────────────────────────────────────────────────────────┐
+       *      │ Shader storage buffer array bindings (see sec. 7.8)           │
+       *      ├─────────────────────┬─────────────────────────────────────────┤
+       *      │  ...                │  ...                                    │
+       *      │  offset restriction │  multiple of value of SHADER_STORAGE_-  │
+       *      │                     │  BUFFER_OFFSET_ALIGNMENT                │
+       *      │  ...                │  ...                                    │
+       *      │  size restriction   │  none                                   │
+       *      └─────────────────────┴─────────────────────────────────────────┘"
+       */
+      if (offsets[i] & (ctx->Const.ShaderStorageBufferOffsetAlignment - 1)) {
+         _mesa_error(ctx, GL_INVALID_VALUE,
+                     "glBindBuffersRange(offsets[%u]=%" PRId64
+                     " is misaligned; it must be a multiple of the value of "
+                     "GL_SHADER_STORAGE_BUFFER_OFFSET_ALIGNMENT=%u when "
+                     "target=GL_SHADER_STORAGE_BUFFER)",
+                     i, (int64_t) offsets[i],
+                     ctx->Const.ShaderStorageBufferOffsetAlignment);
+         continue;
+      }
+
+      if (binding->BufferObject && binding->BufferObject->Name == buffers[i])
+         bufObj = binding->BufferObject;
+      else
+         bufObj = _mesa_multi_bind_lookup_bufferobj(ctx, buffers, i,
+                                                    "glBindBuffersRange");
+
+      if (bufObj) {
+         if (bufObj == ctx->Shared->NullBufferObj)
+            set_ssbo_binding(ctx, binding, bufObj, -1, -1, GL_FALSE);
+         else
+            set_ssbo_binding(ctx, binding, bufObj,
+                             offsets[i], sizes[i], GL_FALSE);
+      }
+   }
+
+   _mesa_end_bufferobj_lookups(ctx);
+}
+
 static bool
 error_check_bind_xfb_buffers(struct gl_context *ctx,
                              struct gl_transform_feedback_object *tfObj,
@@ -4158,6 +4264,10 @@ _mesa_BindBuffersRange(GLenum target, GLuint first, GLsizei count,
    case GL_UNIFORM_BUFFER:
       bind_uniform_buffers_range(ctx, first, count, buffers, offsets, sizes);
       return;
+   case GL_SHADER_STORAGE_BUFFER:
+      bind_shader_storage_buffers_range(ctx, first, count, buffers, offsets,
+                                        sizes);
+      return;
    case GL_ATOMIC_COUNTER_BUFFER:
       bind_atomic_buffers_range(ctx, first, count, buffers,
                                 offsets, sizes);
-- 
2.30.2