[Mesa-dev] [PATCH 1/2] gallium/u_blitter: implement buffer clearing
Brian Paul
brianp at vmware.com
Mon Apr 22 07:42:53 PDT 2013
On 04/21/2013 05:25 PM, Marek Olšák wrote:
> Although this might be useful for ARB_clear_buffer_object,
> I need it for initializating resources in r600g.
> ---
> src/gallium/auxiliary/util/u_blitter.c | 81 +++++++++++++++++++++++++++++---
> src/gallium/auxiliary/util/u_blitter.h | 18 ++++++-
> 2 files changed, 91 insertions(+), 8 deletions(-)
>
> diff --git a/src/gallium/auxiliary/util/u_blitter.c b/src/gallium/auxiliary/util/u_blitter.c
> index 2a4a13e..2f7a1a8 100644
> --- a/src/gallium/auxiliary/util/u_blitter.c
> +++ b/src/gallium/auxiliary/util/u_blitter.c
> @@ -100,7 +100,7 @@ struct blitter_context_priv
> void *velem_state;
> void *velem_uint_state;
> void *velem_sint_state;
> - void *velem_state_readbuf;
> + void *velem_state_readbuf[4];
It took me a minute to understand what '4' is all about. Maybe add a
comment like this:
void *velem_state_readbuf[4]; /**< X, XY, XYZ, XYZW */
>
> /* Sampler state. */
> void *sampler_state;
> @@ -285,9 +285,19 @@ struct blitter_context *util_blitter_create(struct pipe_context *pipe)
> }
>
> if (ctx->has_stream_out) {
> - velem[0].src_format = PIPE_FORMAT_R32_UINT;
> - velem[0].vertex_buffer_index = ctx->base.vb_slot;
> - ctx->velem_state_readbuf = pipe->create_vertex_elements_state(pipe, 1,&velem[0]);
> + static enum pipe_format formats[4] = {
> + PIPE_FORMAT_R32_UINT,
> + PIPE_FORMAT_R32G32_UINT,
> + PIPE_FORMAT_R32G32B32_UINT,
> + PIPE_FORMAT_R32G32B32A32_UINT
> + };
> +
> + for (i = 0; i< 4; i++) {
> + velem[0].src_format = formats[i];
> + velem[0].vertex_buffer_index = ctx->base.vb_slot;
> + ctx->velem_state_readbuf[i] =
> + pipe->create_vertex_elements_state(pipe, 1,&velem[0]);
> + }
> }
>
> /* fragment shaders are created on-demand */
> @@ -352,8 +362,11 @@ void util_blitter_destroy(struct blitter_context *blitter)
> pipe->delete_vertex_elements_state(pipe, ctx->velem_sint_state);
> pipe->delete_vertex_elements_state(pipe, ctx->velem_uint_state);
> }
> - if (ctx->velem_state_readbuf)
> - pipe->delete_vertex_elements_state(pipe, ctx->velem_state_readbuf);
> + for (i = 0; i< 4; i++) {
> + if (ctx->velem_state_readbuf[i]) {
> + pipe->delete_vertex_elements_state(pipe, ctx->velem_state_readbuf[i]);
> + }
> + }
>
> for (i = 0; i< PIPE_MAX_TEXTURE_TYPES; i++) {
> if (ctx->fs_texfetch_col[i])
> @@ -1739,7 +1752,7 @@ void util_blitter_copy_buffer(struct blitter_context *blitter,
> vb.stride = 4;
>
> pipe->set_vertex_buffers(pipe, ctx->base.vb_slot, 1,&vb);
> - pipe->bind_vertex_elements_state(pipe, ctx->velem_state_readbuf);
> + pipe->bind_vertex_elements_state(pipe, ctx->velem_state_readbuf[0]);
> pipe->bind_vs_state(pipe, ctx->vs_pos_only);
> if (ctx->has_geometry_shader)
> pipe->bind_gs_state(pipe, NULL);
> @@ -1756,6 +1769,60 @@ void util_blitter_copy_buffer(struct blitter_context *blitter,
> pipe_so_target_reference(&so_target, NULL);
> }
>
> +void util_blitter_clear_buffer(struct blitter_context *blitter,
> + struct pipe_resource *dst,
> + unsigned offset, unsigned size,
> + unsigned num_channels,
> + const union pipe_color_union *clear_value)
> +{
> + struct blitter_context_priv *ctx = (struct blitter_context_priv*)blitter;
> + struct pipe_context *pipe = ctx->base.pipe;
> + struct pipe_vertex_buffer vb = {0};
> + struct pipe_stream_output_target *so_target;
> +
> + assert(num_channels>= 1);
> + assert(num_channels<= 4);
Do we want some sort of assertion to check that the driver actually
supports SO?
> +
> + /* IMPORTANT: DON'T DO ANY BOUNDS CHECKING HERE!
> + *
> + * R600 uses this to initialize texture resources, so width0 might not be
> + * what you think it is.
> + */
> +
> + /* Some alignment is required. */
> + if (offset % 4 != 0 || size % 4 != 0 || !ctx->has_stream_out) {
> + assert(0);
assert(!"Bad alignment in util_blitter_clear_buffer()");
There's way too many assert(0) macros in gallium, btw.
> + return;
> + }
> +
> + u_upload_data(ctx->upload, 0, num_channels*4, clear_value,
> +&vb.buffer_offset,&vb.buffer);
> + vb.stride = 0;
> +
> + blitter_set_running_flag(ctx);
> + blitter_check_saved_vertex_states(ctx);
> + blitter_disable_render_cond(ctx);
> +
> + pipe->set_vertex_buffers(pipe, ctx->base.vb_slot, 1,&vb);
> + pipe->bind_vertex_elements_state(pipe,
> + ctx->velem_state_readbuf[num_channels-1]);
> + pipe->bind_vs_state(pipe, ctx->vs_pos_only);
> + if (ctx->has_geometry_shader)
> + pipe->bind_gs_state(pipe, NULL);
> + pipe->bind_rasterizer_state(pipe, ctx->rs_discard_state);
> +
> + so_target = pipe->create_stream_output_target(pipe, dst, offset, size);
> + pipe->set_stream_output_targets(pipe, 1,&so_target, 0);
> +
> + util_draw_arrays(pipe, PIPE_PRIM_POINTS, 0, size / 4);
> +
> + blitter_restore_vertex_states(ctx);
> + blitter_restore_render_cond(ctx);
> + blitter_unset_running_flag(ctx);
> + pipe_so_target_reference(&so_target, NULL);
> + pipe_resource_reference(&vb.buffer, NULL);
> +}
> +
> /* probably radeon specific */
> void util_blitter_custom_resolve_color(struct blitter_context *blitter,
> struct pipe_resource *dst,
> diff --git a/src/gallium/auxiliary/util/u_blitter.h b/src/gallium/auxiliary/util/u_blitter.h
> index 20e69ed..1901584 100644
> --- a/src/gallium/auxiliary/util/u_blitter.h
> +++ b/src/gallium/auxiliary/util/u_blitter.h
> @@ -276,7 +276,7 @@ void util_blitter_default_src_texture(struct pipe_sampler_view *src_templ,
>
> /**
> * Copy data from one buffer to another using the Stream Output functionality.
> - * Some alignment is required, otherwise software fallback is used.
> + * 4-byte alignment is required, otherwise software fallback is used.
> */
> void util_blitter_copy_buffer(struct blitter_context *blitter,
> struct pipe_resource *dst,
> @@ -286,6 +286,22 @@ void util_blitter_copy_buffer(struct blitter_context *blitter,
> unsigned size);
>
> /**
> + * Clear the contents of a buffer using the Stream Output functionality.
> + * 4-byte alignment is required.
> + *
> + * "num_channels" can be 1, 2, 3, or 4, and specifies if the clear value is
> + * R, RG, RGB, or RGBA.
> + *
> + * For each element, only "num_channels" components of "clear_value" are
> + * copied to the buffer, then the offset is incremented by num_channels*4.
> + */
> +void util_blitter_clear_buffer(struct blitter_context *blitter,
> + struct pipe_resource *dst,
> + unsigned offset, unsigned size,
> + unsigned num_channels,
> + const union pipe_color_union *clear_value);
> +
> +/**
> * Clear a region of a (color) surface to a constant value.
> *
> * These states must be saved in the blitter in addition to the state objects
Reviewed-by: Brian Paul <brianp at vmware.com>
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