[Mesa-dev] [PATCH v2 1/4] driconf: add allow_higher_compat_version option

[Samuel Pitoiset]

Mesa currently doesn't allow to create 3.1+ compatibility profiles
mainly because various features are unimplemented and bugs can
happen.

However, some buggy apps request a compat profile without using
any old features unimplemented in mesa, and they fail to start.

This option should help some games to run but it's not enough
for all (eg. Dying Ligth).

v2: - s/force_compat_profile/allow_higher_compat_version

Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
---
 src/gallium/include/state_tracker/st_api.h      | 1 +
 src/gallium/state_trackers/dri/dri_screen.c     | 3 +++
 src/mesa/drivers/dri/common/xmlpool/t_options.h | 5 +++++
 src/mesa/drivers/dri/i965/brw_context.c         | 3 +++
 src/mesa/main/mtypes.h                          | 7 +++++++
 src/mesa/main/version.c                         | 6 ++++--
 src/mesa/state_tracker/st_extensions.c          | 2 ++
 7 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/src/gallium/include/state_tracker/st_api.h b/src/gallium/include/state_tracker/st_api.h
index a2e37d2e48..1b9ef290b1 100644
--- a/src/gallium/include/state_tracker/st_api.h
+++ b/src/gallium/include/state_tracker/st_api.h
@@ -245,6 +245,7 @@ struct st_config_options
    unsigned force_glsl_version;
    boolean force_s3tc_enable;
    boolean allow_glsl_extension_directive_midshader;
+   boolean allow_higher_compat_version;
    boolean glsl_zero_init;
 };
 
diff --git a/src/gallium/state_trackers/dri/dri_screen.c b/src/gallium/state_trackers/dri/dri_screen.c
index a950f5241d..1e278c3d1c 100644
--- a/src/gallium/state_trackers/dri/dri_screen.c
+++ b/src/gallium/state_trackers/dri/dri_screen.c
@@ -70,6 +70,7 @@ const __DRIconfigOptionsExtension gallium_config_options = {
          DRI_CONF_DISABLE_SHADER_BIT_ENCODING("false")
          DRI_CONF_FORCE_GLSL_VERSION(0)
          DRI_CONF_ALLOW_GLSL_EXTENSION_DIRECTIVE_MIDSHADER("false")
+         DRI_CONF_ALLOW_HIGHER_COMPAT_VERSION("false")
       DRI_CONF_SECTION_END
 
       DRI_CONF_SECTION_MISCELLANEOUS
@@ -99,6 +100,8 @@ dri_fill_st_options(struct st_config_options *options,
       driQueryOptionb(optionCache, "force_s3tc_enable");
    options->allow_glsl_extension_directive_midshader =
       driQueryOptionb(optionCache, "allow_glsl_extension_directive_midshader");
+   options->allow_higher_compat_version =
+      driQueryOptionb(optionCache, "allow_higher_compat_version");
    options->glsl_zero_init = driQueryOptionb(optionCache, "glsl_zero_init");
 }
 
diff --git a/src/mesa/drivers/dri/common/xmlpool/t_options.h b/src/mesa/drivers/dri/common/xmlpool/t_options.h
index a189bbedec..f200093177 100644
--- a/src/mesa/drivers/dri/common/xmlpool/t_options.h
+++ b/src/mesa/drivers/dri/common/xmlpool/t_options.h
@@ -115,6 +115,11 @@ DRI_CONF_OPT_BEGIN_B(allow_glsl_extension_directive_midshader, def) \
         DRI_CONF_DESC(en,gettext("Allow GLSL #extension directives in the middle of shaders")) \
 DRI_CONF_OPT_END
 
+#define DRI_CONF_ALLOW_HIGHER_COMPAT_VERSION(def) \
+DRI_CONF_OPT_BEGIN_B(allow_higher_compat_version, def) \
+        DRI_CONF_DESC(en,gettext("Allow a higher compat profile (version 3.1+) for apps that request it")) \
+DRI_CONF_OPT_END
+
 
 
 /**
diff --git a/src/mesa/drivers/dri/i965/brw_context.c b/src/mesa/drivers/dri/i965/brw_context.c
index 7240b1f445..c56a14e3d6 100644
--- a/src/mesa/drivers/dri/i965/brw_context.c
+++ b/src/mesa/drivers/dri/i965/brw_context.c
@@ -916,6 +916,9 @@ brw_process_driconf_options(struct brw_context *brw)
    ctx->Const.AllowGLSLExtensionDirectiveMidShader =
       driQueryOptionb(options, "allow_glsl_extension_directive_midshader");
 
+   ctx->Const.AllowHigherCompatVersion =
+      driQueryOptionb(options, "allow_higher_compat_version");
+
    ctx->Const.GLSLZeroInit = driQueryOptionb(options, "glsl_zero_init");
 
    brw->dual_color_blend_by_location =
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index a845a394c8..08bd929255 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -3501,6 +3501,13 @@ struct gl_constants
    GLboolean AllowGLSLExtensionDirectiveMidShader;
 
    /**
+    * Allow creating a higher compat profile (version 3.1+) for apps that
+    * request it. Be careful when adding that driconf option because some
+    * features are unimplemented and might not work correctly.
+    */
+   GLboolean AllowHigherCompatVersion;
+
+   /**
     * Force uninitialized variables to default to zero.
     */
    GLboolean GLSLZeroInit;
diff --git a/src/mesa/main/version.c b/src/mesa/main/version.c
index 85ec9de612..3d54d21a04 100644
--- a/src/mesa/main/version.c
+++ b/src/mesa/main/version.c
@@ -566,8 +566,10 @@ _mesa_get_version(const struct gl_extensions *extensions,
    case API_OPENGL_COMPAT:
       /* Disable GLSL 1.40 and later for legacy contexts.
        * This disallows creation of the GL 3.1 compatibility context. */
-      if (consts->GLSLVersion > 130) {
-         consts->GLSLVersion = 130;
+      if (!consts->AllowHigherCompatVersion) {
+         if (consts->GLSLVersion > 130) {
+            consts->GLSLVersion = 130;
+         }
       }
       /* fall through */
    case API_OPENGL_CORE:
diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
index 293814e3ae..37fe4469c3 100644
--- a/src/mesa/state_tracker/st_extensions.c
+++ b/src/mesa/state_tracker/st_extensions.c
@@ -879,6 +879,8 @@ void st_init_extensions(struct pipe_screen *screen,
       consts->ForceGLSLVersion = options->force_glsl_version;
    }
 
+   consts->AllowHigherCompatVersion = options->allow_higher_compat_version;
+
    if (consts->GLSLVersion >= 400)
       extensions->ARB_gpu_shader5 = GL_TRUE;
    if (consts->GLSLVersion >= 410)
-- 
2.11.1