glsl: Fix output varying initialization when transform feedback is used

This commit is contained in:
ameerj 2021-06-18 00:54:16 -04:00
parent fcff19e0fa
commit 9e066dcb15

View file

@ -12,13 +12,47 @@
namespace Shader::Backend::GLSL {
namespace {
std::string_view OutputVertexIndex(EmitContext& ctx) {
return ctx.stage == Stage::TessellationControl ? "[gl_InvocationID]" : "";
}
void InitializeOutputVaryings(EmitContext& ctx) {
if (ctx.stage == Stage::VertexB || ctx.stage == Stage::Geometry) {
ctx.Add("gl_Position=vec4(0,0,0,1);");
}
for (size_t index = 0; index < 16; ++index) {
if (ctx.info.stores_generics[index]) {
ctx.Add("out_attr{}=vec4(0,0,0,1);", index);
for (size_t index = 0; index < ctx.info.stores_generics.size(); ++index) {
if (!ctx.info.stores_generics[index]) {
continue;
}
const auto& info_array{ctx.output_generics.at(index)};
const auto output_decorator{OutputVertexIndex(ctx)};
size_t element{};
while (element < info_array.size()) {
const auto& info{info_array.at(element)};
const auto varying_name{fmt::format("{}{}", info.name, output_decorator)};
switch (info.num_components) {
case 1: {
const char value{element == 3 ? '1' : '0'};
ctx.Add("{}={}.f;", varying_name, value);
break;
}
case 2:
case 3:
if (element + info.num_components < 4) {
ctx.Add("{}=vec{}(0);", varying_name, info.num_components);
} else {
// last element is the w component, must be initialized to 1
const auto zeros{info.num_components == 3 ? "0,0," : "0,"};
ctx.Add("{}=vec{}({}1);", varying_name, info.num_components, zeros);
}
break;
case 4:
ctx.Add("{}=vec4(0,0,0,1);", varying_name);
break;
default:
break;
}
element += info.num_components;
}
}
}