accept transform-feedback-output target from render

extra/gpu/buffers/buffers.factor

@@ -15,7 +15,8 @@ VARIANT: buffer-access-mode
 
 VARIANT: buffer-kind
     vertex-buffer index-buffer
-    pixel-unpack-buffer pixel-pack-buffer ;
+    pixel-unpack-buffer pixel-pack-buffer
+    transform-feedback-buffer ;
 
 TUPLE: buffer < gpu-object 
     { upload-pattern buffer-upload-pattern }
@@ -52,6 +53,7 @@ TUPLE: buffer < gpu-object
         { index-buffer [ GL_ELEMENT_ARRAY_BUFFER ] }
         { pixel-unpack-buffer [ GL_PIXEL_UNPACK_BUFFER ] }
         { pixel-pack-buffer [ GL_PIXEL_PACK_BUFFER ] }
+        { transform-feedback-buffer [ GL_TRANSFORM_FEEDBACK_BUFFER ] }
     } case ; inline
 
 : get-buffer-int ( target enum -- value )
@@ -82,7 +84,7 @@ UNION: gpu-data-ptr buffer-ptr c-ptr ;
 : buffer-ptr>range ( buffer-ptr -- buffer-range )
     [ buffer>> ] [ offset>> ] bi
     2dup [ buffer-size ] dip -
-    buffer-range boa ;
+    buffer-range boa ; inline
 
 :: allocate-buffer ( buffer size initial-data -- )
     buffer bind-buffer :> target

extra/gpu/render/render.factor

@@ -431,9 +431,33 @@ SYNTAX: UNIFORM-TUPLE:
     dup first sequence?
     [ bind-named-output-attachments ] [ [ drop ] 2dip bind-unnamed-output-attachments ] if ;
 
+GENERIC: bind-transform-feedback-output ( output -- )
+
+M: buffer bind-transform-feedback-output
+    [ GL_TRANSFORM_FEEDBACK_BUFFER 0 ] dip handle>> glBindBufferBase ; inline
+
+M: buffer-range bind-transform-feedback-output
+    [ GL_TRANSFORM_FEEDBACK_BUFFER 0 ] dip
+    [ handle>> ] [ offset>> ] [ size>> ] tri glBindBufferRange ; inline
+
+M: buffer-ptr bind-transform-feedback-output
+    buffer-ptr>range bind-transform-feedback-output ; inline
+
+: gl-feedback-primitive-mode ( primitive-mode -- gl-mode )
+    {
+        { points-mode         [ GL_POINTS    ] }
+        { lines-mode          [ GL_LINES     ] }
+        { line-strip-mode     [ GL_LINES     ] }
+        { line-loop-mode      [ GL_LINES     ] }
+        { triangles-mode      [ GL_TRIANGLES ] }
+        { triangle-strip-mode [ GL_TRIANGLES ] }
+        { triangle-fan-mode   [ GL_TRIANGLES ] }
+    } case ;
+
 PRIVATE>
 
 UNION: ?any-framebuffer any-framebuffer POSTPONE: f ;
+UNION: transform-feedback-output buffer buffer-range POSTPONE: f ;
 
 TUPLE: render-set
     { primitive-mode primitive-mode read-only }
@@ -442,7 +466,8 @@ TUPLE: render-set
     { indexes vertex-indexes initial: T{ index-range } read-only } 
     { instances ?integer initial: f read-only }
     { framebuffer ?any-framebuffer initial: system-framebuffer read-only }
-    { output-attachments sequence initial: { default-attachment } read-only } ;
+    { output-attachments sequence initial: { default-attachment } read-only }
+    { transform-feedback-output transform-feedback-output initial: f read-only } ;
 
 : <render-set> ( x quot-assoc -- render-set )
     render-set swap make-tuple ; inline
@@ -472,11 +497,20 @@ TUPLE: render-set
             bind-output-attachments
         ]
         [ vertex-array>> bind-vertex-array ]
+        [
+            dup transform-feedback-output>> [
+                [ primitive-mode>> gl-feedback-primitive-mode glBeginTransformFeedback ]
+                [ bind-transform-feedback-output ] bi*
+            ] [ drop ] if*
+        ]
+
         [
             [ primitive-mode>> ] [ indexes>> ] [ instances>> ] tri
             [ render-vertex-indexes-instanced ]
             [ render-vertex-indexes ] if*
         ]
+
+        [ transform-feedback-output>> [ glEndTransformFeedback ] when ]
         [ framebuffer>> [ GL_RASTERIZER_DISCARD glDisable ] unless ]
     } cleave ; inline
 

extra/gpu/shaders/shaders.factor

@@ -301,7 +301,8 @@ DEFER: <shader-instance>
     [ compile-shader-error ] if ;
 
 : (link-program) ( program shader-instances -- program-instance )
-    [ [ handle>> ] map ] [ feedback-format>> [ link-feedback-format ] curry ] bi (gl-program)
+    [ [ handle>> ] map ] curry
+    [ feedback-format>> [ link-feedback-format ] curry ] bi (gl-program)
     dup gl-program-ok?
     [ swap world get \ program-instance boa window-resource ]
     [ link-program-error ] if ;