[Mesa-dev] [RFC PATCH 31/56] glsl: Add builtin uniforms for default inner/outer tess levels

[Chris Forbes]

If the hardware needs to always have a control shader present if
and evaluation shader is present, then the control shader will need
these values.
---
 src/glsl/builtin_variables.cpp    | 14 ++++++++++++++
 src/mesa/program/prog_statevars.c | 24 ++++++++++++++++++++++++
 src/mesa/program/prog_statevars.h |  3 +++
 3 files changed, 41 insertions(+)

diff --git a/src/glsl/builtin_variables.cpp b/src/glsl/builtin_variables.cpp
index 97ef68c..0909818 100644
--- a/src/glsl/builtin_variables.cpp
+++ b/src/glsl/builtin_variables.cpp
@@ -33,6 +33,14 @@ static const struct gl_builtin_uniform_element gl_NumSamples_elements[] = {
    {NULL, {STATE_NUM_SAMPLES, 0, 0}, SWIZZLE_XXXX}
 };
 
+static const struct gl_builtin_uniform_element gl_DefaultTessLevelOuterMESA_elements[] = {
+   {NULL, {STATE_INTERNAL, STATE_DEFAULT_TESS_LEVEL_OUTER, 0, 0}, SWIZZLE_XXXX}
+};
+
+static const struct gl_builtin_uniform_element gl_DefaultTessLevelInnerMESA_elements[] = {
+   {NULL, {STATE_INTERNAL, STATE_DEFAULT_TESS_LEVEL_INNER, 0, 0}, SWIZZLE_XXXX}
+};
+
 static const struct gl_builtin_uniform_element gl_DepthRange_elements[] = {
    {"near", {STATE_DEPTH_RANGE, 0, 0}, SWIZZLE_XXXX},
    {"far", {STATE_DEPTH_RANGE, 0, 0}, SWIZZLE_YYYY},
@@ -280,6 +288,9 @@ static const struct gl_builtin_uniform_desc _mesa_builtin_uniform_desc[] = {
    STATEVAR(gl_CurrentAttribVertMESA),
    STATEVAR(gl_CurrentAttribFragMESA),
 
+   STATEVAR(gl_DefaultTessLevelOuterMESA),
+   STATEVAR(gl_DefaultTessLevelInnerMESA),
+
    {NULL, NULL, 0}
 };
 
@@ -743,6 +754,9 @@ builtin_variable_generator::generate_uniforms()
    add_uniform(array(vec4_t, VERT_ATTRIB_MAX), "gl_CurrentAttribVertMESA");
    add_uniform(array(vec4_t, VARYING_SLOT_MAX), "gl_CurrentAttribFragMESA");
 
+   add_uniform(array(float_t, 4), "gl_DefaultTessLevelOuterMESA");
+   add_uniform(array(float_t, 2), "gl_DefaultTessLevelInnerMESA");
+
    if (compatibility) {
       add_uniform(mat4_t, "gl_ModelViewMatrix");
       add_uniform(mat4_t, "gl_ProjectionMatrix");
diff --git a/src/mesa/program/prog_statevars.c b/src/mesa/program/prog_statevars.c
index be5ddb1..785257b 100644
--- a/src/mesa/program/prog_statevars.c
+++ b/src/mesa/program/prog_statevars.c
@@ -593,6 +593,20 @@ _mesa_fetch_state(struct gl_context *ctx, const gl_state_index state[],
          }
          return;
 
+      case STATE_DEFAULT_TESS_LEVEL_OUTER:
+         value[0] = ctx->TessCtrlProgram.patch_default_outer_level[state[2]];
+         value[1] = 0.0F;
+         value[2] = 0.0F;
+         value[3] = 0.0F;
+         return;
+
+      case STATE_DEFAULT_TESS_LEVEL_INNER:
+         value[0] = ctx->TessCtrlProgram.patch_default_inner_level[state[2]];
+         value[1] = 0.0F;
+         value[2] = 0.0F;
+         value[3] = 0.0F;
+         return;
+
       /* XXX: make sure new tokens added here are also handled in the 
        * _mesa_program_state_flags() switch, below.
        */
@@ -703,6 +717,10 @@ _mesa_program_state_flags(const gl_state_index state[STATE_LENGTH])
       case STATE_FB_WPOS_Y_TRANSFORM:
          return _NEW_BUFFERS;
 
+      case STATE_DEFAULT_TESS_LEVEL_OUTER:
+      case STATE_DEFAULT_TESS_LEVEL_INNER:
+         return _NEW_PROGRAM;
+
       default:
          /* unknown state indexes are silently ignored and
          *  no flag set, since it is handled by the driver.
@@ -909,6 +927,12 @@ append_token(char *dst, gl_state_index k)
    case STATE_FB_WPOS_Y_TRANSFORM:
       append(dst, "FbWposYTransform");
       break;
+   case STATE_DEFAULT_TESS_LEVEL_OUTER:
+      append(dst, "DefaultTessLevelOuter");
+      break;
+   case STATE_DEFAULT_TESS_LEVEL_INNER:
+      append(dst, "DefaultTessLevelInner");
+      break;
    default:
       /* probably STATE_INTERNAL_DRIVER+i (driver private state) */
       append(dst, "driverState");
diff --git a/src/mesa/program/prog_statevars.h b/src/mesa/program/prog_statevars.h
index 6333e63..7240398 100644
--- a/src/mesa/program/prog_statevars.h
+++ b/src/mesa/program/prog_statevars.h
@@ -128,6 +128,9 @@ typedef enum gl_state_index_ {
    STATE_PT_BIAS,               /**< Pixel transfer RGBA bias */
    STATE_FB_SIZE,               /**< (width-1, height-1, 0, 0) */
    STATE_FB_WPOS_Y_TRANSFORM,   /**< (1, 0, -1, height) if a FBO is bound, (-1, height, 1, 0) otherwise */
+
+   STATE_DEFAULT_TESS_LEVEL_OUTER,
+   STATE_DEFAULT_TESS_LEVEL_INNER,
    STATE_INTERNAL_DRIVER	/* first available state index for drivers (must be last) */
 } gl_state_index;
 
-- 
2.1.0