mesa: Implement _mesa_BindBuffersBase for target GL_SHADER_STORAGE_BUFFER

v2:
- Add space before const (Jordan)

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

src/mesa/main/bufferobj.c

@@ -3033,6 +3033,33 @@ set_ubo_binding(struct gl_context *ctx,
       bufObj->UsageHistory |= USAGE_UNIFORM_BUFFER;
 }
 
+/**
+ * Binds a buffer object to a shader storage buffer binding point.
+ *
+ * The caller is responsible for flushing vertices and updating
+ * NewDriverState.
+ */
+static void
+set_ssbo_binding(struct gl_context *ctx,
+                 struct gl_shader_storage_buffer_binding *binding,
+                 struct gl_buffer_object *bufObj,
+                 GLintptr offset,
+                 GLsizeiptr size,
+                 GLboolean autoSize)
+{
+   _mesa_reference_buffer_object(ctx, &binding->BufferObject, bufObj);
+
+   binding->Offset = offset;
+   binding->Size = size;
+   binding->AutomaticSize = autoSize;
+
+   /* If this is a real buffer object, mark it has having been used
+    * at some point as a SSBO.
+    */
+   if (size >= 0)
+      bufObj->UsageHistory |= USAGE_SHADER_STORAGE_BUFFER;
+}
+
 /**
  * Binds a buffer object to a uniform buffer binding point.
  *
@@ -3254,6 +3281,35 @@ error_check_bind_uniform_buffers(struct gl_context *ctx,
    return true;
 }
 
+static bool
+error_check_bind_shader_storage_buffers(struct gl_context *ctx,
+                                        GLuint first, GLsizei count,
+                                        const char *caller)
+{
+   if (!ctx->Extensions.ARB_shader_storage_buffer_object) {
+      _mesa_error(ctx, GL_INVALID_ENUM,
+                  "%s(target=GL_SHADER_STORAGE_BUFFER)", caller);
+      return false;
+   }
+
+   /* The ARB_multi_bind_spec says:
+    *
+    *     "An INVALID_OPERATION error is generated if <first> + <count> is
+    *      greater than the number of target-specific indexed binding points,
+    *      as described in section 6.7.1."
+    */
+   if (first + count > ctx->Const.MaxShaderStorageBufferBindings) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "%s(first=%u + count=%d > the value of "
+                  "GL_MAX_SHADER_STORAGE_BUFFER_BINDINGS=%u)",
+                  caller, first, count,
+                  ctx->Const.MaxShaderStorageBufferBindings);
+      return false;
+   }
+
+   return true;
+}
+
 /**
  * Unbind all uniform buffers in the range
  * <first> through <first>+<count>-1
@@ -3269,6 +3325,22 @@ unbind_uniform_buffers(struct gl_context *ctx, GLuint first, GLsizei count)
                       bufObj, -1, -1, GL_TRUE);
 }
 
+/**
+ * Unbind all shader storage buffers in the range
+ * <first> through <first>+<count>-1
+ */
+static void
+unbind_shader_storage_buffers(struct gl_context *ctx, GLuint first,
+                              GLsizei count)
+{
+   struct gl_buffer_object *bufObj = ctx->Shared->NullBufferObj;
+   GLint i;
+
+   for (i = 0; i < count; i++)
+      set_ssbo_binding(ctx, &ctx->ShaderStorageBufferBindings[first + i],
+                       bufObj, -1, -1, GL_TRUE);
+}
+
 static void
 bind_uniform_buffers_base(struct gl_context *ctx, GLuint first, GLsizei count,
                           const GLuint *buffers)
@@ -3335,6 +3407,73 @@ bind_uniform_buffers_base(struct gl_context *ctx, GLuint first, GLsizei count,
    _mesa_end_bufferobj_lookups(ctx);
 }
 
+static void
+bind_shader_storage_buffers_base(struct gl_context *ctx, GLuint first,
+                                 GLsizei count, const GLuint *buffers)
+{
+   GLint i;
+
+   if (!error_check_bind_shader_storage_buffers(ctx, first, count,
+                                                "glBindBuffersBase"))
+      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."
+       */
+      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 (binding->BufferObject && binding->BufferObject->Name == buffers[i])
+         bufObj = binding->BufferObject;
+      else
+         bufObj = _mesa_multi_bind_lookup_bufferobj(ctx, buffers, i,
+                                                    "glBindBuffersBase");
+
+      if (bufObj) {
+         if (bufObj == ctx->Shared->NullBufferObj)
+            set_ssbo_binding(ctx, binding, bufObj, -1, -1, GL_TRUE);
+         else
+            set_ssbo_binding(ctx, binding, bufObj, 0, 0, GL_TRUE);
+      }
+   }
+
+   _mesa_end_bufferobj_lookups(ctx);
+}
+
 static void
 bind_uniform_buffers_range(struct gl_context *ctx, GLuint first, GLsizei count,
                            const GLuint *buffers,
@@ -4043,6 +4182,9 @@ _mesa_BindBuffersBase(GLenum target, GLuint first, GLsizei count,
    case GL_UNIFORM_BUFFER:
       bind_uniform_buffers_base(ctx, first, count, buffers);
       return;
+   case GL_SHADER_STORAGE_BUFFER:
+      bind_shader_storage_buffers_base(ctx, first, count, buffers);
+      return;
    case GL_ATOMIC_COUNTER_BUFFER:
       bind_atomic_buffers_base(ctx, first, count, buffers);
       return;

src/mesa/main/mtypes.h

@@ -1459,6 +1459,7 @@ typedef enum {
    USAGE_UNIFORM_BUFFER = 0x1,
    USAGE_TEXTURE_BUFFER = 0x2,
    USAGE_ATOMIC_COUNTER_BUFFER = 0x4,
+   USAGE_SHADER_STORAGE_BUFFER = 0x8,
 } gl_buffer_usage;
 
 
@@ -4034,6 +4035,12 @@ struct gl_driver_flags
     */
    uint64_t NewUniformBuffer;
 
+   /**
+    * gl_context::ShaderStorageBufferBindings
+    * gl_shader_program::ShaderStorageBlocks
+    */
+   uint64_t NewShaderStorageBuffer;
+
    uint64_t NewTextureBuffer;
 
    /**