mesa/st: move DrawBufferAllocate into mesa.

Little bit of refactoring here.

Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14675>

src/mesa/main/buffers.c

@@ -35,6 +35,7 @@
 #include "context.h"
 #include "enums.h"
 #include "fbobject.h"
+#include "framebuffer.h"
 #include "hash.h"
 #include "mtypes.h"
 #include "state.h"
@@ -321,7 +322,8 @@ draw_buffer(struct gl_context *ctx, struct gl_framebuffer *fb,
 
    /* Call device driver function only if fb is the bound draw buffer */
    if (fb == ctx->DrawBuffer) {
-      st_DrawBufferAllocate(ctx);
+      if (_mesa_is_winsys_fbo(ctx->DrawBuffer))
+         _mesa_draw_buffer_allocate(ctx);
    }
 }
 
@@ -627,7 +629,8 @@ draw_buffers(struct gl_context *ctx, struct gl_framebuffer *fb, GLsizei n,
     * may not be valid.
     */
    if (fb == ctx->DrawBuffer) {
-      st_DrawBufferAllocate(ctx);
+      if (_mesa_is_winsys_fbo(ctx->DrawBuffer))
+         _mesa_draw_buffer_allocate(ctx);
    }
 }
 

src/mesa/main/framebuffer.c

@@ -49,6 +49,7 @@
 #include "util/u_memory.h"
 
 #include "state_tracker/st_cb_fbo.h"
+#include "state_tracker/st_manager.h"
 
 /**
  * Compute/set the _DepthMax field for the given framebuffer.
@@ -581,6 +582,29 @@ update_color_read_buffer(struct gl_framebuffer *fb)
    }
 }
 
+/**
+ * Called via glDrawBuffer.  We only provide this driver function so that we
+ * can check if we need to allocate a new renderbuffer.  Specifically, we
+ * don't usually allocate a front color buffer when using a double-buffered
+ * visual.  But if the app calls glDrawBuffer(GL_FRONT) we need to allocate
+ * that buffer.  Note, this is only for window system buffers, not user-
+ * created FBOs.
+ */
+void
+_mesa_draw_buffer_allocate(struct gl_context *ctx)
+{
+   struct gl_framebuffer *fb = ctx->DrawBuffer;
+   assert(_mesa_is_winsys_fbo(fb));
+   GLuint i;
+   /* add the renderbuffers on demand */
+   for (i = 0; i < fb->_NumColorDrawBuffers; i++) {
+      gl_buffer_index idx = fb->_ColorDrawBufferIndexes[i];
+
+      if (idx != BUFFER_NONE) {
+         st_manager_add_color_renderbuffer(st_context(ctx), fb, idx);
+      }
+   }
+}
 
 /**
  * Update a gl_framebuffer's derived state.
@@ -611,7 +635,7 @@ update_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb)
 
       /* Call device driver function if fb is the bound draw buffer. */
       if (fb == ctx->DrawBuffer) {
-         st_DrawBufferAllocate(ctx);
+         _mesa_draw_buffer_allocate(ctx);
       }
    }
    else {

src/mesa/main/framebuffer.h

@@ -143,4 +143,7 @@ _mesa_is_multisample_enabled(const struct gl_context *ctx);
 extern bool
 _mesa_is_alpha_test_enabled(const struct gl_context *ctx);
 
+void
+_mesa_draw_buffer_allocate(struct gl_context *ctx);
+
 #endif /* FRAMEBUFFER_H */

src/mesa/state_tracker/st_cb_fbo.c

@@ -536,33 +536,6 @@ st_update_renderbuffer_surface(struct st_context *st,
    rb->surface = *psurf;
 }
 
-/**
- * Called via glDrawBuffer.  We only provide this driver function so that we
- * can check if we need to allocate a new renderbuffer.  Specifically, we
- * don't usually allocate a front color buffer when using a double-buffered
- * visual.  But if the app calls glDrawBuffer(GL_FRONT) we need to allocate
- * that buffer.  Note, this is only for window system buffers, not user-
- * created FBOs.
- */
-void
-st_DrawBufferAllocate(struct gl_context *ctx)
-{
-   struct st_context *st = st_context(ctx);
-   struct gl_framebuffer *fb = ctx->DrawBuffer;
-
-   if (_mesa_is_winsys_fbo(fb)) {
-      GLuint i;
-      /* add the renderbuffers on demand */
-      for (i = 0; i < fb->_NumColorDrawBuffers; i++) {
-         gl_buffer_index idx = fb->_ColorDrawBufferIndexes[i];
-
-         if (idx != BUFFER_NONE) {
-            st_manager_add_color_renderbuffer(st, fb, idx);
-         }
-      }
-   }
-}
-
 /**
  * Called via ctx->Driver.MapRenderbuffer.
  */

src/mesa/state_tracker/st_cb_fbo.h

@@ -78,7 +78,6 @@ st_renderbuffer_alloc_storage(struct gl_context * ctx,
                               struct gl_renderbuffer *rb,
                               GLenum internalFormat,
                               GLuint width, GLuint height);
-void st_DrawBufferAllocate(struct gl_context *ctx);
 
 void st_MapRenderbuffer(struct gl_context *ctx,
                         struct gl_renderbuffer *rb,