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Diffstat (limited to 'src/mesa/tnl/t_vp_build.c')
-rw-r--r--src/mesa/tnl/t_vp_build.c23
1 files changed, 15 insertions, 8 deletions
diff --git a/src/mesa/tnl/t_vp_build.c b/src/mesa/tnl/t_vp_build.c
index dff062a417c..2a1cae77f29 100644
--- a/src/mesa/tnl/t_vp_build.c
+++ b/src/mesa/tnl/t_vp_build.c
@@ -1103,7 +1103,9 @@ static void build_fog( struct tnl_program *p )
{
struct ureg fog = register_output(p, VERT_RESULT_FOGC);
struct ureg input;
-
+ GLuint useabs = p->state->fog_source_is_depth && p->state->fog_mode &&
+ (p->state->fog_mode != FOG_EXP2);
+
if (p->state->fog_source_is_depth) {
input = swizzle1(get_eye_position(p), Z);
}
@@ -1111,31 +1113,36 @@ static void build_fog( struct tnl_program *p )
input = swizzle1(register_input(p, VERT_ATTRIB_FOG), X);
}
- if (p->state->tnl_do_vertex_fog) {
+ if (p->state->fog_mode && p->state->tnl_do_vertex_fog) {
struct ureg params = register_param2(p, STATE_INTERNAL,
STATE_FOG_PARAMS_OPTIMIZED);
struct ureg tmp = get_temp(p);
+ if (useabs) {
+ emit_op1(p, OPCODE_ABS, tmp, 0, input);
+ }
+
switch (p->state->fog_mode) {
case FOG_LINEAR: {
struct ureg id = get_identity_param(p);
- emit_op3(p, OPCODE_MAD, tmp, 0, input, swizzle1(params,X), swizzle1(params,Y));
+ emit_op3(p, OPCODE_MAD, tmp, 0, useabs ? tmp : input,
+ swizzle1(params,X), swizzle1(params,Y));
emit_op2(p, OPCODE_MAX, tmp, 0, tmp, swizzle1(id,X)); /* saturate */
emit_op2(p, OPCODE_MIN, fog, WRITEMASK_X, tmp, swizzle1(id,W));
break;
}
case FOG_EXP:
- emit_op1(p, OPCODE_ABS, tmp, 0, input);
- emit_op2(p, OPCODE_MUL, tmp, 0, tmp, swizzle1(params,Z));
+ emit_op2(p, OPCODE_MUL, tmp, 0, useabs ? tmp : input,
+ swizzle1(params,Z));
emit_op1(p, OPCODE_EX2, fog, WRITEMASK_X, negate(tmp));
break;
case FOG_EXP2:
emit_op2(p, OPCODE_MUL, tmp, 0, input, swizzle1(params,W));
- emit_op2(p, OPCODE_MUL, tmp, 0, tmp, tmp);
+ emit_op2(p, OPCODE_MUL, tmp, 0, tmp, tmp);
emit_op1(p, OPCODE_EX2, fog, WRITEMASK_X, negate(tmp));
break;
}
-
+
release_temp(p, tmp);
}
else {
@@ -1143,7 +1150,7 @@ static void build_fog( struct tnl_program *p )
*
* KW: Is it really necessary to do anything in this case?
*/
- emit_op1(p, OPCODE_MOV, fog, WRITEMASK_X, input);
+ emit_op1(p, useabs ? OPCODE_ABS : OPCODE_MOV, fog, WRITEMASK_X, input);
}
}