[Mesa-dev] [PATCH 1/2] mesa: Add core API support for GL_ARB_stencil_texturing (from 4.3).
Kenneth Graunke
kenneth at whitecape.org
Sun Feb 23 21:59:24 PST 2014
While the GL_ARB_stencil_texturing extension does not allow the creation
of stencil textures, it does allow shaders to sample stencil values
stored in packed depth/stencil textures.
Specifically, applications can call glTexParameter* with a pname of
GL_DEPTH_STENCIL_TEXTURE_MODE and value of either GL_DEPTH_COMPONENT or
GL_STENCIL_INDEX to select which component they wish to sample. The
default value is GL_DEPTH_COMPONENT (for traditional depth sampling).
Shaders should use an unsigned integer sampler (presumably usampler2D)
to access stencil data. Otherwise, results are undefined. Using shadow
samplers with GL_STENCIL_INDEX selected also is undefined behavior.
This patch creates a new gl_texture_object field, StencilSampling, to
indicate that stencil should be sampled rather than depth. (I chose to
use a boolean since I figured it would be more convenient for drivers.)
It also introduces the [Get]TexParameter code to get and set the value,
and of course the extension plumbing.
Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
docs/GL3.txt | 2 +-
src/mapi/glapi/gen/GL4x.xml | 2 +-
src/mesa/main/extensions.c | 1 +
src/mesa/main/mtypes.h | 2 ++
src/mesa/main/texobj.c | 2 ++
src/mesa/main/texparam.c | 28 ++++++++++++++++++++++++++++
6 files changed, 35 insertions(+), 2 deletions(-)
diff --git a/docs/GL3.txt b/docs/GL3.txt
index 542ee28..33910ec 100644
--- a/docs/GL3.txt
+++ b/docs/GL3.txt
@@ -158,7 +158,7 @@ GL 4.3:
GL_ARB_robust_buffer_access_behavior not started
GL_ARB_shader_image_size not started
GL_ARB_shader_storage_buffer_object not started
- GL_ARB_stencil_texturing not started
+ GL_ARB_stencil_texturing API exists, no drivers
GL_ARB_texture_buffer_range DONE (nv50, nvc0, i965, r600, radeonsi)
GL_ARB_texture_query_levels DONE (i965)
GL_ARB_texture_storage_multisample DONE (all drivers that support GL_ARB_texture_multisample)
diff --git a/src/mapi/glapi/gen/GL4x.xml b/src/mapi/glapi/gen/GL4x.xml
index 6706278..8efef0b 100644
--- a/src/mapi/glapi/gen/GL4x.xml
+++ b/src/mapi/glapi/gen/GL4x.xml
@@ -15,7 +15,7 @@
</category>
<category name="4.3">
-
+ <enum name="DEPTH_STENCIL_TEXTURE_MODE" value="0x90EA"/>
</category>
</OpenGLAPI>
diff --git a/src/mesa/main/extensions.c b/src/mesa/main/extensions.c
index 2611db8..8712564 100644
--- a/src/mesa/main/extensions.c
+++ b/src/mesa/main/extensions.c
@@ -137,6 +137,7 @@ static const struct extension extension_table[] = {
{ "GL_ARB_shading_language_packing", o(ARB_shading_language_packing), GL, 2011 },
{ "GL_ARB_shading_language_420pack", o(ARB_shading_language_420pack), GL, 2011 },
{ "GL_ARB_shadow", o(ARB_shadow), GLL, 2001 },
+ { "GL_ARB_stencil_texturing", o(ARB_stencil_texturing), GL, 2012 },
{ "GL_ARB_sync", o(ARB_sync), GL, 2003 },
{ "GL_ARB_texture_border_clamp", o(ARB_texture_border_clamp), GLL, 2000 },
{ "GL_ARB_texture_buffer_object", o(ARB_texture_buffer_object), GLC, 2008 },
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index fbbca55..6da3eb6 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -1199,6 +1199,7 @@ struct gl_texture_object
struct gl_sampler_object Sampler;
GLenum DepthMode; /**< GL_ARB_depth_texture */
+ bool StencilSampling; /**< Should we sample stencil instead of depth? */
GLfloat Priority; /**< in [0,1] */
GLint BaseLevel; /**< min mipmap level, OpenGL 1.2 */
@@ -3509,6 +3510,7 @@ struct gl_extensions
GLboolean ARB_shading_language_packing;
GLboolean ARB_shading_language_420pack;
GLboolean ARB_shadow;
+ GLboolean ARB_stencil_texturing;
GLboolean ARB_sync;
GLboolean ARB_texture_border_clamp;
GLboolean ARB_texture_buffer_object;
diff --git a/src/mesa/main/texobj.c b/src/mesa/main/texobj.c
index 6adc0ae..9ab539f 100644
--- a/src/mesa/main/texobj.c
+++ b/src/mesa/main/texobj.c
@@ -148,6 +148,7 @@ _mesa_initialize_texture_object( struct gl_context *ctx,
obj->Sampler.CompareMode = GL_NONE; /* ARB_shadow */
obj->Sampler.CompareFunc = GL_LEQUAL; /* ARB_shadow */
obj->DepthMode = ctx->API == API_OPENGL_CORE ? GL_RED : GL_LUMINANCE;
+ obj->StencilSampling = false;
obj->Sampler.CubeMapSeamless = GL_FALSE;
obj->Swizzle[0] = GL_RED;
obj->Swizzle[1] = GL_GREEN;
@@ -280,6 +281,7 @@ _mesa_copy_texture_object( struct gl_texture_object *dest,
dest->Sampler.CompareFunc = src->Sampler.CompareFunc;
dest->Sampler.CubeMapSeamless = src->Sampler.CubeMapSeamless;
dest->DepthMode = src->DepthMode;
+ dest->StencilSampling = src->StencilSampling;
dest->Sampler.sRGBDecode = src->Sampler.sRGBDecode;
dest->_MaxLevel = src->_MaxLevel;
dest->_MaxLambda = src->_MaxLambda;
diff --git a/src/mesa/main/texparam.c b/src/mesa/main/texparam.c
index bbdbc27..92c2a49 100644
--- a/src/mesa/main/texparam.c
+++ b/src/mesa/main/texparam.c
@@ -451,6 +451,20 @@ set_tex_parameteri(struct gl_context *ctx,
}
goto invalid_pname;
+ case GL_DEPTH_STENCIL_TEXTURE_MODE:
+ if (_mesa_is_desktop_gl(ctx) && ctx->Extensions.ARB_stencil_texturing) {
+ bool stencil = params[0] == GL_STENCIL_INDEX;
+ if (!stencil && params[0] != GL_DEPTH_COMPONENT)
+ goto invalid_param;
+
+ if (texObj->StencilSampling == stencil)
+ return GL_FALSE;
+
+ texObj->StencilSampling = stencil;
+ return GL_TRUE;
+ }
+ goto invalid_pname;
+
case GL_TEXTURE_CROP_RECT_OES:
if (ctx->API != API_OPENGLES || !ctx->Extensions.OES_draw_texture)
goto invalid_pname;
@@ -707,6 +721,7 @@ _mesa_TexParameterf(GLenum target, GLenum pname, GLfloat param)
case GL_TEXTURE_COMPARE_MODE_ARB:
case GL_TEXTURE_COMPARE_FUNC_ARB:
case GL_DEPTH_TEXTURE_MODE_ARB:
+ case GL_DEPTH_STENCIL_TEXTURE_MODE:
case GL_TEXTURE_SRGB_DECODE_EXT:
case GL_TEXTURE_CUBE_MAP_SEAMLESS:
case GL_TEXTURE_SWIZZLE_R_EXT:
@@ -762,6 +777,7 @@ _mesa_TexParameterfv(GLenum target, GLenum pname, const GLfloat *params)
case GL_TEXTURE_COMPARE_MODE_ARB:
case GL_TEXTURE_COMPARE_FUNC_ARB:
case GL_DEPTH_TEXTURE_MODE_ARB:
+ case GL_DEPTH_STENCIL_TEXTURE_MODE:
case GL_TEXTURE_SRGB_DECODE_EXT:
case GL_TEXTURE_CUBE_MAP_SEAMLESS:
{
@@ -1452,6 +1468,12 @@ _mesa_GetTexParameterfv( GLenum target, GLenum pname, GLfloat *params )
goto invalid_pname;
*params = (GLfloat) obj->DepthMode;
break;
+ case GL_DEPTH_STENCIL_TEXTURE_MODE:
+ if (!_mesa_is_desktop_gl(ctx) || !ctx->Extensions.ARB_stencil_texturing)
+ goto invalid_pname;
+ *params = (GLfloat)
+ (obj->StencilSampling ? GL_STENCIL_INDEX : GL_DEPTH_COMPONENT);
+ break;
case GL_TEXTURE_LOD_BIAS:
if (_mesa_is_gles(ctx))
goto invalid_pname;
@@ -1666,6 +1688,12 @@ _mesa_GetTexParameteriv( GLenum target, GLenum pname, GLint *params )
goto invalid_pname;
*params = (GLint) obj->DepthMode;
break;
+ case GL_DEPTH_STENCIL_TEXTURE_MODE:
+ if (!_mesa_is_desktop_gl(ctx) || !ctx->Extensions.ARB_stencil_texturing)
+ goto invalid_pname;
+ *params = (GLint)
+ (obj->StencilSampling ? GL_STENCIL_INDEX : GL_DEPTH_COMPONENT);
+ break;
case GL_TEXTURE_LOD_BIAS:
if (_mesa_is_gles(ctx))
goto invalid_pname;
--
1.8.4.2
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