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authorBrian Paul <brianp@vmware.com>2010-02-13 13:57:31 -0700
committerBrian Paul <brianp@vmware.com>2010-02-13 13:57:33 -0700
commitc2c4935cb8fe8601c72f585f70d776e3a65f15dc (patch)
tree4a933f93f6bed5d4b52399c6dbf412d25f79d17e /src/mesa
parent26661ac0e10aba63de093e871e40d336696f4827 (diff)
glsl: implement layout qualifiers
For GL_ARB_fragment_coord_conventions. This only applies to gl_FragCoord and controls pixel center origin and pixel center integer. For example: layout (origin_upper_left, pixel_center_integer) varying vec4 gl_FragCoord; This features introduces the idea of re-declaring variables with a changed type. This may also apply to arrays in some cases but that's not implemented at this time.
Diffstat (limited to 'src/mesa')
-rw-r--r--src/mesa/shader/slang/slang_compile.c129
1 files changed, 110 insertions, 19 deletions
diff --git a/src/mesa/shader/slang/slang_compile.c b/src/mesa/shader/slang/slang_compile.c
index 852274119c..1dce3adf89 100644
--- a/src/mesa/shader/slang/slang_compile.c
+++ b/src/mesa/shader/slang/slang_compile.c
@@ -636,6 +636,38 @@ parse_type_centroid(slang_parse_ctx * C, slang_type_centroid *centroid)
}
+/* Layout qualifiers */
+#define LAYOUT_QUALIFIER_NONE 0
+#define LAYOUT_QUALIFIER_UPPER_LEFT 1
+#define LAYOUT_QUALIFIER_PIXEL_CENTER_INTEGER 2
+
+static int
+parse_layout_qualifiers(slang_parse_ctx * C, slang_layout_qualifier *layout)
+{
+ *layout = 0x0;
+
+ /* the layout qualifiers come as a list of LAYOUT_QUALIFER_x tokens,
+ * terminated by LAYOUT_QUALIFIER_NONE.
+ */
+ while (1) {
+ GLuint c = *C->I++;
+ switch (c) {
+ case LAYOUT_QUALIFIER_NONE:
+ /* end of list of qualifiers */
+ return 1;
+ case LAYOUT_QUALIFIER_UPPER_LEFT:
+ *layout |= SLANG_LAYOUT_UPPER_LEFT_BIT;
+ break;
+ case LAYOUT_QUALIFIER_PIXEL_CENTER_INTEGER:
+ *layout |= SLANG_LAYOUT_PIXEL_CENTER_INTEGER_BIT;
+ break;
+ default:
+ assert(0 && "Bad layout qualifier");
+ }
+ }
+}
+
+
/* type qualifier */
#define TYPE_QUALIFIER_NONE 0
#define TYPE_QUALIFIER_CONST 1
@@ -907,9 +939,12 @@ static int
parse_fully_specified_type(slang_parse_ctx * C, slang_output_ctx * O,
slang_fully_specified_type * type)
{
+ if (!parse_layout_qualifiers(C, &type->layout))
+ RETURN0;
+
if (!parse_type_variant(C, &type->variant))
RETURN0;
-
+
if (!parse_type_centroid(C, &type->centroid))
RETURN0;
@@ -2029,6 +2064,30 @@ initialize_global(slang_assemble_ctx * A, slang_variable * var)
/**
+ * Check if it's OK to re-declare a variable with the given new type.
+ * This happens when applying layout qualifiers to gl_FragCoord or
+ * (re)setting an array size.
+ * If redeclaration is OK, return a pointer to the incoming variable
+ * updated with new type info. Else return NULL;
+ */
+static slang_variable *
+redeclare_variable(slang_variable *var,
+ const slang_fully_specified_type *type)
+{
+ if (slang_fully_specified_types_compatible(&var->type, type)) {
+ /* replace orig var layout with new layout */
+ var->type.layout = type->layout;
+
+ /* XXX there may be other type updates in the future here */
+
+ return var;
+ }
+ else
+ return NULL;
+}
+
+
+/**
* Parse the initializer for a variable declaration.
*/
static int
@@ -2036,7 +2095,7 @@ parse_init_declarator(slang_parse_ctx * C, slang_output_ctx * O,
const slang_fully_specified_type * type)
{
GET_CURRENT_CONTEXT(ctx); /* a hack */
- slang_variable *var;
+ slang_variable *var = NULL, *prevDecl;
slang_atom a_name;
/* empty init declatator (without name, e.g. "float ;") */
@@ -2046,29 +2105,41 @@ parse_init_declarator(slang_parse_ctx * C, slang_output_ctx * O,
a_name = parse_identifier(C);
/* check if name is already in this scope */
- if (_slang_variable_locate(O->vars, a_name, GL_FALSE)) {
- slang_info_log_error(C->L,
+ prevDecl = _slang_variable_locate(O->vars, a_name, C->global_scope);
+ if (prevDecl) {
+ /* A var with this name has already been declared.
+ * Check if redeclaring the var with a different type/layout is legal.
+ */
+ if (C->global_scope) {
+ var = redeclare_variable(prevDecl, type);
+ }
+ if (!var) {
+ slang_info_log_error(C->L,
"declaration of '%s' conflicts with previous declaration",
(char *) a_name);
- RETURN0;
+ RETURN0;
+ }
}
- /* make room for the new variable and initialize it */
- var = slang_variable_scope_grow(O->vars);
if (!var) {
- slang_info_log_memory(C->L);
- RETURN0;
- }
+ /* make room for a new variable and initialize it */
+ var = slang_variable_scope_grow(O->vars);
+ if (!var) {
+ slang_info_log_memory(C->L);
+ RETURN0;
+ }
- /* copy the declarator type qualifier/etc info, parse the identifier */
- var->type.qualifier = type->qualifier;
- var->type.centroid = type->centroid;
- var->type.precision = type->precision;
- var->type.variant = type->variant;
- var->type.array_len = type->array_len;
- var->a_name = a_name;
- if (var->a_name == SLANG_ATOM_NULL)
- RETURN0;
+ /* copy the declarator type qualifier/etc info, parse the identifier */
+ var->type.qualifier = type->qualifier;
+ var->type.centroid = type->centroid;
+ var->type.precision = type->precision;
+ var->type.variant = type->variant;
+ var->type.layout = type->layout;
+ var->type.array_len = type->array_len;
+ var->a_name = a_name;
+ if (var->a_name == SLANG_ATOM_NULL)
+ RETURN0;
+ }
switch (*C->I++) {
case VARIABLE_NONE:
@@ -2169,6 +2240,21 @@ parse_init_declarator(slang_parse_ctx * C, slang_output_ctx * O,
RETURN0;
}
}
+
+ if (var->type.qualifier == SLANG_QUAL_FIXEDINPUT &&
+ var->a_name == slang_atom_pool_atom(C->atoms, "gl_FragCoord")) {
+ /* set the program's PixelCenterInteger, OriginUpperLeft fields */
+ struct gl_fragment_program *fragProg =
+ (struct gl_fragment_program *) O->program;
+
+ if (var->type.layout & SLANG_LAYOUT_UPPER_LEFT_BIT) {
+ fragProg->OriginUpperLeft = GL_TRUE;
+ }
+ if (var->type.layout & SLANG_LAYOUT_PIXEL_CENTER_INTEGER_BIT) {
+ fragProg->PixelCenterInteger = GL_TRUE;
+ }
+ }
+
return 1;
}
@@ -2615,6 +2701,11 @@ compile_with_grammar(const char *source,
return GL_FALSE;
}
+ if (type == SLANG_UNIT_FRAGMENT_SHADER) {
+ sl_pp_context_add_extension(context, "GL_ARB_fragment_coord_conventions");
+ }
+
+
#if FEATURE_es2_glsl
if (sl_pp_context_add_predefined(context, "GL_ES", "1") ||
sl_pp_context_add_predefined(context, "GL_FRAGMENT_PRECISION_HIGH", "1")) {