[Mesa-dev] [PATCH v2 5/5] meta: Add a meta implementation of GL_ARB_clear_texture

Pohjolainen, Topi topi.pohjolainen at intel.com
Wed Jul 2 23:47:11 PDT 2014


On Wed, Jul 02, 2014 at 07:00:06PM +0100, Neil Roberts wrote:
> Adds an implementation of the ClearTexSubImage driver entry point that tries
> to set up an FBO to render to the texture and then calls glClear with a
> scissor to perform the actual clear. If an FBO can't be created for the
> texture then it will fall back to using _mesa_store_ClearTexSubImage.
> 
> When used in combination with _mesa_store_ClearTexSubImage this
> should provide an implementation that works for all DRI-based drivers. However
> as this has only been tested with the i965 driver it is currently only enabled
> there.
> 
> v2: Only enable the extension for the i965 driver instead of all DRI drivers.
>     Remove an unnecessary goto. Don't require GL_ARB_framebuffer_object. Add
>     some more comments.
> ---
>  src/mesa/drivers/common/driverfuncs.c        |   1 +
>  src/mesa/drivers/common/meta.c               | 163 +++++++++++++++++++++++++++
>  src/mesa/drivers/common/meta.h               |   7 ++
>  src/mesa/drivers/dri/i965/intel_extensions.c |   1 +
>  4 files changed, 172 insertions(+)
> 
> diff --git a/src/mesa/drivers/common/driverfuncs.c b/src/mesa/drivers/common/driverfuncs.c
> index 6ece5d8..4f0f7a6 100644
> --- a/src/mesa/drivers/common/driverfuncs.c
> +++ b/src/mesa/drivers/common/driverfuncs.c
> @@ -95,6 +95,7 @@ _mesa_init_driver_functions(struct dd_function_table *driver)
>     driver->TexImage = _mesa_store_teximage;
>     driver->TexSubImage = _mesa_store_texsubimage;
>     driver->GetTexImage = _mesa_meta_GetTexImage;
> +   driver->ClearTexSubImage = _mesa_meta_ClearTexSubImage;
>     driver->CopyTexSubImage = _mesa_meta_CopyTexSubImage;
>     driver->GenerateMipmap = _mesa_meta_GenerateMipmap;
>     driver->TestProxyTexImage = _mesa_test_proxy_teximage;
> diff --git a/src/mesa/drivers/common/meta.c b/src/mesa/drivers/common/meta.c
> index f1f5729..141178e 100644
> --- a/src/mesa/drivers/common/meta.c
> +++ b/src/mesa/drivers/common/meta.c
> @@ -40,6 +40,7 @@
>  #include "main/blit.h"
>  #include "main/bufferobj.h"
>  #include "main/buffers.h"
> +#include "main/clear.h"
>  #include "main/colortab.h"
>  #include "main/condrender.h"
>  #include "main/depth.h"
> @@ -47,6 +48,7 @@
>  #include "main/fbobject.h"
>  #include "main/feedback.h"
>  #include "main/formats.h"
> +#include "main/format_unpack.h"
>  #include "main/glformats.h"
>  #include "main/image.h"
>  #include "main/macros.h"
> @@ -71,6 +73,7 @@
>  #include "main/teximage.h"
>  #include "main/texparam.h"
>  #include "main/texstate.h"
> +#include "main/texstore.h"
>  #include "main/transformfeedback.h"
>  #include "main/uniforms.h"
>  #include "main/varray.h"
> @@ -3339,3 +3342,163 @@ _mesa_meta_DrawTex(struct gl_context *ctx, GLfloat x, GLfloat y, GLfloat z,
>  
>     _mesa_meta_end(ctx);
>  }
> +
> +static void
> +set_color_clear_value(struct gl_context *ctx,
> +                      mesa_format format,
> +                      const GLvoid *clearValue)
> +{
> +   if (clearValue == 0) {
> +         memset(&ctx->Color.ClearColor, 0, sizeof ctx->Color.ClearColor);
> +   } else {
> +      switch (_mesa_get_format_datatype(format)) {
> +      case GL_UNSIGNED_INT:
> +      case GL_INT:
> +         _mesa_unpack_uint_rgba_row(format, 1, clearValue,
> +                                    (GLuint (*)[4]) ctx->Color.ClearColor.ui);
> +         break;
> +      default:
> +         _mesa_unpack_rgba_row(format, 1, clearValue,
> +                               (GLfloat (*)[4]) ctx->Color.ClearColor.f);
> +         break;
> +      }
> +   }
> +}
> +
> +static bool
> +cleartexsubimage_using_fbo_for_zoffset(struct gl_context *ctx,
> +                                       struct gl_texture_image *texImage,
> +                                       GLint xoffset, GLint yoffset,
> +                                       GLint zoffset,
> +                                       GLsizei width, GLsizei height,
> +                                       const GLvoid *clearValue)
> +{
> +   GLuint fbo;
> +   bool success = false;
> +   GLbitfield mask;
> +   GLenum status;
> +
> +   _mesa_GenFramebuffers(1, &fbo);
> +   _mesa_BindFramebuffer(GL_DRAW_FRAMEBUFFER, fbo);
> +
> +   if (texImage->_BaseFormat == GL_DEPTH_STENCIL ||
> +       texImage->_BaseFormat == GL_DEPTH_COMPONENT) {
> +      _mesa_meta_bind_fbo_image(GL_DEPTH_ATTACHMENT, texImage, zoffset);
> +      mask = GL_DEPTH_BUFFER_BIT;
> +
> +      if (clearValue) {
> +         GLuint depthStencilValue[2];
> +         GLfloat depthValue;
> +
> +         /* Convert the clearValue from whatever format it's in to a floating
> +          * point value for the depth and an integer value for the stencil
> +          * index so we can set the clear values */

I wonder what I was reading the first time, this call is clearly the right
thing to do as it handles all the combinations - sorry for the confusion.

Small nit for the comment style here and in the rest of the patch, in mesa
it's:

            /* Convert the clearValue from whatever format it's in to a floating
             * point value for the depth and an integer value for the stencil
             * index so we can set the clear values.
             */

> +         _mesa_unpack_float_32_uint_24_8_depth_stencil_row(texImage->TexFormat,
> +                                                           1, /* n */
> +                                                           clearValue,
> +                                                           depthStencilValue);
> +         /* We need a memcpy here instead of a cast because we need to
> +          * reinterpret the bytes as a float rather than converting it */
> +         memcpy(&depthValue, depthStencilValue, sizeof depthValue);
> +         ctx->Depth.Clear = depthValue;

And the use of the temporary float is also correct as "ctx->Stencil.Clear" has
double precision type (GLclampd). I need to be more careful in the future.

> +         ctx->Stencil.Clear = depthStencilValue[1] & 0xff;
> +      } else {
> +         ctx->Depth.Clear = 0.0;
> +         ctx->Stencil.Clear = 0;
> +      }
> +
> +      if (texImage->_BaseFormat == GL_DEPTH_STENCIL) {
> +         _mesa_meta_bind_fbo_image(GL_STENCIL_ATTACHMENT, texImage, zoffset);
> +         mask |= GL_STENCIL_BUFFER_BIT;
> +      }
> +      _mesa_DrawBuffer(GL_NONE);
> +   } else {
> +      _mesa_meta_bind_fbo_image(GL_COLOR_ATTACHMENT0, texImage, zoffset);
> +      _mesa_DrawBuffer(GL_COLOR_ATTACHMENT0);
> +      mask = GL_COLOR_BUFFER_BIT;
> +
> +      set_color_clear_value(ctx, texImage->TexFormat, clearValue);
> +   }
> +
> +   status = _mesa_CheckFramebufferStatus(GL_DRAW_FRAMEBUFFER);
> +   if (status != GL_FRAMEBUFFER_COMPLETE)
> +      goto out;
> +
> +   _mesa_set_enable(ctx, GL_SCISSOR_TEST, GL_TRUE);
> +   _mesa_Scissor(xoffset, yoffset, width, height);
> +   _mesa_Clear(mask);
> +
> +   success = true;
> +
> + out:
> +   _mesa_DeleteFramebuffers(1, &fbo);
> +   return success;
> +}
> +
> +static bool
> +cleartexsubimage_using_fbo(struct gl_context *ctx,
> +                           struct gl_texture_image *texImage,
> +                           GLint xoffset, GLint yoffset, GLint zoffset,
> +                           GLsizei width, GLsizei height, GLsizei depth,
> +                           const GLvoid *clearValue)
> +{
> +   union gl_color_union saveColorValue;
> +   bool success = true;
> +   GLint z;
> +
> +   _mesa_meta_begin(ctx,
> +                    MESA_META_SCISSOR |
> +                    MESA_META_COLOR_MASK |
> +                    MESA_META_DEPTH_TEST |
> +                    MESA_META_STENCIL_TEST);
> +
> +   /* _mesa_meta_begin doesn't seem to save this. It does however save the
> +    * clear values for the depth and stencil */
> +   saveColorValue = ctx->Color.ClearColor;

Oh, I didn't realize that. Should we fix and put this into
_mesa_meta_begin/_mesa_meta_end instead?

With that (could be a follow-up as well) and the comment style fixed, this is:

Reviewed-by: Topi Pohjolainen <topi.pohjolainen at intel.com>

> +
> +   for (z = zoffset; z < zoffset + depth; z++) {
> +      if (!cleartexsubimage_using_fbo_for_zoffset(ctx, texImage,
> +                                                  xoffset, yoffset, z,
> +                                                  width, height,
> +                                                  clearValue)) {
> +         success = false;
> +         break;
> +      }
> +   }
> +
> +   ctx->Color.ClearColor = saveColorValue;
> +   _mesa_meta_end(ctx);
> +
> +   return success;
> +}
> +
> +extern void
> +_mesa_meta_ClearTexSubImage(struct gl_context *ctx,
> +                            struct gl_texture_image *texImage,
> +                            GLint xoffset, GLint yoffset, GLint zoffset,
> +                            GLsizei width, GLsizei height, GLsizei depth,
> +                            const GLvoid *clearValue)
> +{
> +   bool res;
> +
> +   _mesa_unlock_texture(ctx, texImage->TexObject);
> +
> +   res = cleartexsubimage_using_fbo(ctx, texImage,
> +                                    xoffset, yoffset, zoffset,
> +                                    width, height, depth,
> +                                    clearValue);
> +
> +   _mesa_lock_texture(ctx, texImage->TexObject);
> +
> +   if (res)
> +      return;
> +
> +   _mesa_warning(ctx,
> +                 "Falling back to mapping the texture in "
> +                 "glClearTexSubImage\n");
> +
> +   _mesa_store_cleartexsubimage(ctx, texImage,
> +                                xoffset, yoffset, zoffset,
> +                                width, height, depth,
> +                                clearValue);
> +}
> diff --git a/src/mesa/drivers/common/meta.h b/src/mesa/drivers/common/meta.h
> index 765f8df..863ab3f 100644
> --- a/src/mesa/drivers/common/meta.h
> +++ b/src/mesa/drivers/common/meta.h
> @@ -473,6 +473,13 @@ _mesa_meta_CopyTexSubImage(struct gl_context *ctx, GLuint dims,
>                             GLsizei width, GLsizei height);
>  
>  extern void
> +_mesa_meta_ClearTexSubImage(struct gl_context *ctx,
> +                            struct gl_texture_image *texImage,
> +                            GLint xoffset, GLint yoffset, GLint zoffset,
> +                            GLsizei width, GLsizei height, GLsizei depth,
> +                            const GLvoid *clearValue);
> +
> +extern void
>  _mesa_meta_GetTexImage(struct gl_context *ctx,
>                         GLenum format, GLenum type, GLvoid *pixels,
>                         struct gl_texture_image *texImage);
> diff --git a/src/mesa/drivers/dri/i965/intel_extensions.c b/src/mesa/drivers/dri/i965/intel_extensions.c
> index 281d6c4..93f1355 100644
> --- a/src/mesa/drivers/dri/i965/intel_extensions.c
> +++ b/src/mesa/drivers/dri/i965/intel_extensions.c
> @@ -163,6 +163,7 @@ intelInitExtensions(struct gl_context *ctx)
>     assert(brw->gen >= 4);
>  
>     ctx->Extensions.ARB_buffer_storage = true;
> +   ctx->Extensions.ARB_clear_texture = true;
>     ctx->Extensions.ARB_depth_buffer_float = true;
>     ctx->Extensions.ARB_depth_clamp = true;
>     ctx->Extensions.ARB_depth_texture = true;
> -- 
> 1.9.3
> 
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