mesa: add Layered field to framebuffers

When checking framebuffer completeness, we test each attachment.
We verify that all attachments are consistent in terms of layers.

1. They must all be layered, or all non-layered
2. If they are layered, they must match in depth

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Brian Paul <brianp@vmware.com>

src/mesa/main/fbobject.c

@@ -777,6 +777,8 @@ _mesa_test_framebuffer_completeness(struct gl_context *ctx,
    GLint fixedSampleLocations = -1;
    GLint i;
    GLuint j;
+   bool layer_count_valid = false;
+   GLuint layer_count = 0, att_layer_count;
 
    assert(_mesa_is_user_fbo(fb));
 
@@ -949,8 +951,26 @@ _mesa_test_framebuffer_completeness(struct gl_context *ctx,
          fbo_incomplete("unsupported renderbuffer format", i);
          return;
       }
+
+      /* Check that layered rendering is consistent. */
+      att_layer_count = att->Layered ? att->Renderbuffer->Depth : 0;
+      if (!layer_count_valid) {
+         layer_count = att_layer_count;
+         layer_count_valid = true;
+      } else if (layer_count != att_layer_count) {
+         if (layer_count == 0 || att_layer_count == 0) {
+            fb->_Status = GL_FRAMEBUFFER_INCOMPLETE_LAYER_TARGETS;
+            fbo_incomplete("framebuffer attachment layer mode is inconsistent", i);
+         } else {
+            fb->_Status = GL_FRAMEBUFFER_INCOMPLETE_LAYER_COUNT_ARB;
+            fbo_incomplete("framebuffer attachment layer count is inconsistent", i);
+         }
+         return;
+      }
    }
 
+   fb->Layered = layer_count > 0;
+
    if (_mesa_is_desktop_gl(ctx) && !ctx->Extensions.ARB_ES2_compatibility) {
       /* Check that all DrawBuffers are present */
       for (j = 0; j < ctx->Const.MaxDrawBuffers; j++) {

src/mesa/main/mtypes.h

@@ -2683,6 +2683,8 @@ struct gl_framebuffer
    struct gl_renderbuffer *_ColorDrawBuffers[MAX_DRAW_BUFFERS];
    struct gl_renderbuffer *_ColorReadBuffer;
 
+   GLboolean Layered;
+
    /** Delete this framebuffer */
    void (*Delete)(struct gl_framebuffer *fb);
 };