From c2c4935cb8fe8601c72f585f70d776e3a65f15dc Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Sat, 13 Feb 2010 13:57:31 -0700 Subject: 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. --- src/mesa/shader/slang/slang_compile.c | 129 +++++++++++++++++++++++++++++----- 1 file changed, 110 insertions(+), 19 deletions(-) (limited to 'src') 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; @@ -2028,6 +2063,30 @@ initialize_global(slang_assemble_ctx * A, slang_variable * var) #define VARIABLE_ARRAY_UNKNOWN 4 +/** + * 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. */ @@ -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")) { -- cgit v1.2.3