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vcc glsl backend upgrades #37

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f83ae5c
Fixed prefix for AsUniformConstant when emitting GLSL
JuanDiegoMontoya May 6, 2024
3fb5d50
Added more address spaces to avoid emitting initializers for.
JuanDiegoMontoya May 7, 2024
59f6544
Emit location qualifier when targeting GLSL
JuanDiegoMontoya May 7, 2024
006f80a
Reorganize qualifier-emitting code
JuanDiegoMontoya May 9, 2024
599e8a1
Support for UBOs and SSBOs of fixed lengths
JuanDiegoMontoya May 9, 2024
04884c9
Restore gitignore
JuanDiegoMontoya May 9, 2024
06de81e
Simplify annotation helper
JuanDiegoMontoya May 10, 2024
58611db
Hack to strip illegal identifiers (containing double underscores) fro…
JuanDiegoMontoya May 12, 2024
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115 changes: 87 additions & 28 deletions src/shady/emit/c/emit_c.c
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Original file line number Diff line number Diff line change
Expand Up @@ -70,6 +70,36 @@ String legalize_c_identifier(Emitter* e, String src) {
return string(e->arena, dst);
}

// For uniform constants, explicit locations require version 430 or ARB_explicit_uniform_location.
static bool glsl_as_can_have_location(AddressSpace as) {
return as == AsUniformConstant || as == AsInput || as == AsUInput || as == AsOutput;
}

// Samplers and images (uniform constants)
// Version 420 required.
static bool glsl_as_can_have_binding(AddressSpace as) {
return as == AsUniformConstant || as == AsShaderStorageBufferObject || as == AsUniform;
}

static String glsl_try_make_single_int_qualifier(Emitter* emitter, const Node* decl, Nodes annotations, String annotation_name, String glsl_qualifier_name) {
const Node* a_node = lookup_annotation_list(annotations, annotation_name);
if (a_node) {
assert(is_annotation(a_node));
if (a_node->tag == AnnotationValue_TAG) {
const Node* value = a_node->payload.annotation_value.value;
if (value->tag == IntLiteral_TAG) {
uint64_t location = value->payload.int_literal.value;
return format_string_arena(emitter->arena->arena, "%s = %" PRIu64, glsl_qualifier_name, location);
}
warn_print("warning: %s must be an integer literal\n", annotation_name);
} else {
warn_print("warning: %s annotations must contain exactly one integer value\n", annotation_name);
}
}

return NULL;
}

#include <ctype.h>

static enum { ObjectsList, StringLit, CharsLit } array_insides_helper(Emitter* e, Printer* block_printer, Printer* p, Growy* g, const Node* t, Nodes c) {
Expand Down Expand Up @@ -116,7 +146,7 @@ static bool has_forward_declarations(CDialect dialect) {
}
}

static void emit_global_variable_definition(Emitter* emitter, AddressSpace as, String decl_center, const Type* type, bool constant, String init, const Nodes* annotations) {
static void emit_global_variable_definition(Emitter* emitter, AddressSpace as, String decl_center, const Type* type, bool constant, String init, Strings qualifiers) {
String prefix = NULL;

// GLSL wants 'const' to go on the left to start the declaration, but in C const should go on the right (east const convention)
Expand Down Expand Up @@ -168,6 +198,8 @@ static void emit_global_variable_definition(Emitter* emitter, AddressSpace as, S
prefix = "const ";
break;
}
case AsUniform:
case AsShaderStorageBufferObject: prefix = ""; break;
default: {
prefix = format_string_arena(emitter->arena->arena, "/* %s */", get_address_space_name(as));
warn_print("warning: address space %s not supported in GLSL for global variables\n", get_address_space_name(as));
Expand All @@ -188,34 +220,38 @@ static void emit_global_variable_definition(Emitter* emitter, AddressSpace as, S
decl_center = format_string_arena(emitter->arena->arena, "varying %s", decl_center);
}

String qualifiers = "";

if (emitter->config.dialect == CDialect_GLSL) {
// Binding and location qualifiers are allowed together on opaque uniform constants, but it's not very useful.
// For uniform constants, explicit locations require version 430 or ARB_explicit_uniform_location.
if (as == AsUniformConstant || as == AsInput || as == AsUInput || as == AsOutput) {
const Node* a_location = lookup_annotation_list(*annotations, "Location");
if (a_location) {
assert(is_annotation(a_location));
if (a_location->tag == AnnotationValue_TAG) {
const Node* value = a_location->payload.annotation_value.value;
if (value->tag == IntLiteral_TAG) {
uint64_t location = value->payload.int_literal.value;
qualifiers = format_string_arena(emitter->arena->arena, "layout(location = %" PRIu64 ") ", location);
} else {
warn_print("warning: location must be an integer literal\n");
}
} else {
warn_print("warning: location annotations must contain exactly one integer value\n");
}

print(emitter->fn_decls, "\n");

if (qualifiers.count > 0) {
if (emitter->config.dialect == CDialect_GLSL) {
print(emitter->fn_decls, "layout(");

for (size_t i = 0; i < qualifiers.count; i++) {
print(emitter->fn_decls, "%s%s", qualifiers.strings[i], (i == qualifiers.count - 1) ? "" : ", ");
}

print(emitter->fn_decls, ") ");
}
}

// Emit first part of block (uniform or storage buffer)
bool is_glsl_block = emitter->config.dialect == CDialect_GLSL && (as == AsShaderStorageBufferObject || as == AsUniform);
if (is_glsl_block) {
String interface_qualifier = as == AsUniform ? "uniform" : "buffer";
String block_name = as == AsUniform ? "ubo" : "ssbo";
print(emitter->fn_decls, "%s %s_%s {\n ", interface_qualifier, unique_name(emitter->arena, ""), block_name);
}

if (init)
print(emitter->fn_decls, "\n%s%s%s = %s;", qualifiers, prefix, emit_type(emitter, type, decl_center), init);
print(emitter->fn_decls, "%s%s = %s;", prefix, emit_type(emitter, type, decl_center), init);
else
print(emitter->fn_decls, "\n%s%s%s;", qualifiers, prefix, emit_type(emitter, type, decl_center));
print(emitter->fn_decls, "%s%s;", prefix, emit_type(emitter, type, decl_center));

// Emit second half of block
if (is_glsl_block) {
print(emitter->fn_decls, "\n};");
}

//if (!has_forward_declarations(emitter->config.dialect) || !init)
// return;
Expand Down Expand Up @@ -278,7 +314,7 @@ CTerm emit_value(Emitter* emitter, Printer* block_printer, const Node* value) {
if (emitter->config.dialect == CDialect_GLSL)
return emit_value(emitter, block_printer, get_default_zero_value(emitter->arena, value->payload.undef.type));
String name = unique_name(emitter->arena, "undef");
emit_global_variable_definition(emitter, AsGlobal, name, value->payload.undef.type, true, NULL, NULL);
emit_global_variable_definition(emitter, AsGlobal, name, value->payload.undef.type, true, NULL, (Strings){.count = 0});
emitted = name;
break;
}
Expand Down Expand Up @@ -626,9 +662,32 @@ void emit_decl(Emitter* emitter, const Node* decl) {
}
register_emitted(emitter, decl, emit_as);

const Nodes* annotations = &decl->payload.global_variable.annotations;
AddressSpace as = decl->payload.global_variable.address_space;
emit_global_variable_definition(emitter, as, decl_center, decl_type, false, init, annotations);
// Generate list of qualifiers
Growy* g = new_growy();
Nodes annotations = decl->payload.global_variable.annotations;

if (emitter->config.dialect == CDialect_GLSL) {
if (glsl_as_can_have_location(ass)) {
String location_qualifier = glsl_try_make_single_int_qualifier(emitter, decl, annotations, "Location", "location");
if (location_qualifier)
growy_append_bytes(g, sizeof(String), (const char*)&location_qualifier);
}

if (glsl_as_can_have_binding(ass)) {
if (ass == AsShaderStorageBufferObject)
growy_append_bytes(g, sizeof(String), (const char*)&(String){"std430"});
if (ass == AsUniform)
growy_append_bytes(g, sizeof(String), (const char*)&(String){"std140"});

String binding_qualifier = glsl_try_make_single_int_qualifier(emitter, decl, annotations, "DescriptorBinding", "binding");
if (binding_qualifier)
growy_append_bytes(g, sizeof(String), (const char*)&binding_qualifier);
}
}

Strings qualifier_strings = strings(emitter->arena, growy_size(g) / sizeof(String), (const char**)growy_data(g));
emit_global_variable_definition(emitter, ass, decl_center, decl_type, false, init, qualifier_strings);
destroy_growy(g);
return;
}
case Function_TAG: {
Expand Down Expand Up @@ -674,7 +733,7 @@ void emit_decl(Emitter* emitter, const Node* decl) {
const Node* init_value = get_quoted_value(decl->payload.constant.instruction);
assert(init_value && "TODO: support some measure of constant expressions");
String init = to_cvalue(emitter, emit_value(emitter, NULL, init_value));
emit_global_variable_definition(emitter, AsGlobal, decl_center, decl->type, true, init, NULL);
emit_global_variable_definition(emitter, AsGlobal, decl_center, decl->type, true, init, (Strings) { .count = 0 });
return;
}
case NominalType_TAG: {
Expand Down