glsl: Fix gl_NormalScale.

GLSL shaders can access the normal scale factor with the built-in
gl_NormalScale.  Mesa's modelspace lighting optimization uses a different
normal scale factor than defined in the spec.  We have to take care not
to use this factor for gl_NormalScale.

Mesa already defines two seperate states: state.normalScale and
state.internal.normalScale.  The first is used by the glsl compiler
while the later is used by the fixed function T&L pipeline.  Previously
the only difference was some component swizzling.  With this commit
state.normalScale always uses the normal scale factor for eyespace
lighting.

Reviewed-by: Brian Paul <brianp@vmware.com>
This commit is contained in:
Fabian Bieler
2017-11-23 13:48:00 -07:00
committed by Brian Paul
parent 27888977c1
commit c3ee464d7a
3 changed files with 6 additions and 2 deletions

View File

@@ -1032,6 +1032,7 @@ static void
update_modelview_scale( struct gl_context *ctx ) update_modelview_scale( struct gl_context *ctx )
{ {
ctx->_ModelViewInvScale = 1.0F; ctx->_ModelViewInvScale = 1.0F;
ctx->_ModelViewInvScaleEyespace = 1.0F;
if (!_math_matrix_is_length_preserving(ctx->ModelviewMatrixStack.Top)) { if (!_math_matrix_is_length_preserving(ctx->ModelviewMatrixStack.Top)) {
const GLfloat *m = ctx->ModelviewMatrixStack.Top->inv; const GLfloat *m = ctx->ModelviewMatrixStack.Top->inv;
GLfloat f = m[2] * m[2] + m[6] * m[6] + m[10] * m[10]; GLfloat f = m[2] * m[2] + m[6] * m[6] + m[10] * m[10];
@@ -1040,6 +1041,7 @@ update_modelview_scale( struct gl_context *ctx )
ctx->_ModelViewInvScale = 1.0f / sqrtf(f); ctx->_ModelViewInvScale = 1.0f / sqrtf(f);
else else
ctx->_ModelViewInvScale = sqrtf(f); ctx->_ModelViewInvScale = sqrtf(f);
ctx->_ModelViewInvScaleEyespace = 1.0f / sqrtf(f);
} }
} }
@@ -1216,4 +1218,5 @@ _mesa_init_lighting( struct gl_context *ctx )
ctx->_NeedEyeCoords = GL_FALSE; ctx->_NeedEyeCoords = GL_FALSE;
ctx->_ForceEyeCoords = GL_FALSE; ctx->_ForceEyeCoords = GL_FALSE;
ctx->_ModelViewInvScale = 1.0; ctx->_ModelViewInvScale = 1.0;
ctx->_ModelViewInvScaleEyespace = 1.0;
} }

View File

@@ -4961,7 +4961,8 @@ struct gl_context
/** \name Derived state */ /** \name Derived state */
GLbitfield _ImageTransferState;/**< bitwise-or of IMAGE_*_BIT flags */ GLbitfield _ImageTransferState;/**< bitwise-or of IMAGE_*_BIT flags */
GLfloat _EyeZDir[3]; GLfloat _EyeZDir[3];
GLfloat _ModelViewInvScale; GLfloat _ModelViewInvScale; /* may be for model- or eyespace lighting */
GLfloat _ModelViewInvScaleEyespace; /* always factor defined in spec */
GLboolean _NeedEyeCoords; GLboolean _NeedEyeCoords;
GLboolean _ForceEyeCoords; GLboolean _ForceEyeCoords;

View File

@@ -422,7 +422,7 @@ _mesa_fetch_state(struct gl_context *ctx, const gl_state_index state[],
return; return;
case STATE_NORMAL_SCALE: case STATE_NORMAL_SCALE:
ASSIGN_4V(value, ctx->_ModelViewInvScale, 0, 0, 1); ASSIGN_4V(value, ctx->_ModelViewInvScaleEyespace, 0, 0, 1);
return; return;
case STATE_INTERNAL: case STATE_INTERNAL: