gallium: Add a util_blitter path for using a custom VS and FS.

Like the r600 paths to use other custom states, we pass in a couple of
parameters to customize the innards of the blitter.  It's up to the caller
to wrap other state necessary for its shaders (for example, constant
buffers for the uniforms the shader uses).

Reviewed-by: Marek Olšák <marek.olsak@amd.com>

2 files changed, 69 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/util/u_blitter.c b/src/gallium/auxiliary/util/u_blitter.c
index 98c3ac5df3..4748627fc5 100644
--- a/src/gallium/auxiliary/util/u_blitter.c
+++ b/src/gallium/auxiliary/util/u_blitter.c
@@ -129,6 +129,8 @@ struct blitter_context_priv
    unsigned dst_width;
    unsigned dst_height;
 
+   void *custom_vs;
+
    bool has_geometry_shader;
    bool has_tessellation;
    bool has_layered;
@@ -2564,3 +2566,65 @@ void util_blitter_custom_color(struct blitter_context *blitter,
    util_blitter_restore_render_cond(blitter);
    util_blitter_unset_running_flag(blitter);
 }
+
+static void *get_custom_vs(struct blitter_context *blitter)
+{
+   struct blitter_context_priv *ctx = (struct blitter_context_priv*)blitter;
+
+   return ctx->custom_vs;
+}
+
+/**
+ * Performs a custom blit to the destination surface, using the VS and FS
+ * provided.
+ *
+ * Used by vc4 for the 8-bit linear-to-tiled blit.
+ */
+void util_blitter_custom_shader(struct blitter_context *blitter,
+                                struct pipe_surface *dstsurf,
+                                void *custom_vs, void *custom_fs)
+{
+   struct blitter_context_priv *ctx = (struct blitter_context_priv*)blitter;
+   struct pipe_context *pipe = ctx->base.pipe;
+   struct pipe_framebuffer_state fb_state;
+
+   ctx->custom_vs = custom_vs;
+
+   assert(dstsurf->texture);
+   if (!dstsurf->texture)
+      return;
+
+   /* check the saved state */
+   util_blitter_set_running_flag(blitter);
+   blitter_check_saved_vertex_states(ctx);
+   blitter_check_saved_fragment_states(ctx);
+   blitter_check_saved_fb_state(ctx);
+   blitter_disable_render_cond(ctx);
+
+   /* bind states */
+   pipe->bind_blend_state(pipe, ctx->blend[PIPE_MASK_RGBA][0]);
+   pipe->bind_depth_stencil_alpha_state(pipe, ctx->dsa_keep_depth_stencil);
+   pipe->bind_fs_state(pipe, custom_fs);
+   pipe->set_sample_mask(pipe, (1ull << MAX2(1, dstsurf->texture->nr_samples)) - 1);
+
+   /* set a framebuffer state */
+   fb_state.width = dstsurf->width;
+   fb_state.height = dstsurf->height;
+   fb_state.nr_cbufs = 1;
+   fb_state.cbufs[0] = dstsurf;
+   fb_state.zsbuf = 0;
+   pipe->set_framebuffer_state(pipe, &fb_state);
+   pipe->set_sample_mask(pipe, ~0);
+
+   blitter_set_common_draw_rect_state(ctx, false);
+   blitter_set_dst_dimensions(ctx, dstsurf->width, dstsurf->height);
+   blitter->draw_rectangle(blitter, ctx->velem_state, get_custom_vs,
+                           0, 0, dstsurf->width, dstsurf->height,
+                           0, 1, UTIL_BLITTER_ATTRIB_NONE, NULL);
+
+   util_blitter_restore_vertex_states(blitter);
+   util_blitter_restore_fragment_states(blitter);
+   util_blitter_restore_fb_state(blitter);
+   util_blitter_restore_render_cond(blitter);
+   util_blitter_unset_running_flag(blitter);
+}
diff --git a/src/gallium/auxiliary/util/u_blitter.h b/src/gallium/auxiliary/util/u_blitter.h
index dba773906a..9e945983ba 100644
--- a/src/gallium/auxiliary/util/u_blitter.h
+++ b/src/gallium/auxiliary/util/u_blitter.h
@@ -384,6 +384,11 @@ void util_blitter_custom_resolve_color(struct blitter_context *blitter,
                                        void *custom_blend,
                                        enum pipe_format format);
 
+/* Used by vc4 for 8/16-bit linear-to-tiled blits */
+void util_blitter_custom_shader(struct blitter_context *blitter,
+                                struct pipe_surface *dstsurf,
+                                void *custom_vs, void *custom_fs);
+
 /* The functions below should be used to save currently bound constant state
  * objects inside a driver. The objects are automatically restored at the end
  * of the util_blitter_{clear, copy_region, fill_region} functions and then