vulkan_renderer: Alpha Test Culling Implementation

Used by various textures in many titles, e.g.  SSBU menu.
merge-requests/60/head
ameerj 2020-11-18 20:08:51 +07:00
parent d1da7eb119
commit 9014861858
5 changed files with 76 additions and 2 deletions

@ -60,6 +60,11 @@ void FixedPipelineState::Fill(const Maxwell& regs, bool has_extended_dynamic_sta
rasterize_enable.Assign(regs.rasterize_enable != 0 ? 1 : 0);
topology.Assign(regs.draw.topology);
alpha_raw = 0;
alpha_test_enabled.Assign(regs.alpha_test_enabled);
alpha_test_func.Assign(PackComparisonOp(regs.alpha_test_func));
std::memcpy(&alpha_test_ref, &regs.alpha_test_ref, sizeof(u32)); // TODO: C++20 std::bit_cast
std::memcpy(&point_size, &regs.point_size, sizeof(point_size)); // TODO: C++20 std::bit_cast
for (std::size_t index = 0; index < Maxwell::NumVertexArrays; ++index) {

@ -187,6 +187,14 @@ struct FixedPipelineState {
BitField<23, 1, u32> rasterize_enable;
BitField<24, 4, Maxwell::PrimitiveTopology> topology;
};
u32 alpha_test_ref; /// < Alpha test reference
union {
u32 alpha_raw;
BitField<0, 3, u32> alpha_test_func;
BitField<3, 1, u32> alpha_test_enabled;
};
u32 point_size;
std::array<u32, Maxwell::NumVertexArrays> binding_divisors;
std::array<VertexAttribute, Maxwell::NumVertexAttributes> attributes;

@ -344,6 +344,14 @@ VKPipelineCache::DecompileShaders(const FixedPipelineState& fixed_state) {
}
specialization.ndc_minus_one_to_one = fixed_state.ndc_minus_one_to_one;
// Alpha test
if (fixed_state.alpha_test_enabled == 1) {
specialization.alpha_test_enabled = true;
specialization.alpha_test_func = static_cast<u8>(fixed_state.alpha_test_func);
// memcpy from u32 to float TODO: C++20 std::bit_cast
std::memcpy(&specialization.alpha_test_ref, &fixed_state.alpha_test_ref, sizeof(float));
}
SPIRVProgram program;
std::vector<VkDescriptorSetLayoutBinding> bindings;

@ -2075,6 +2075,55 @@ private:
return {};
}
void AlphaTest(const Id& pointer) {
const Id true_label = OpLabel();
const Id skip_label = OpLabel();
Id condition;
switch (specialization.alpha_test_func) {
case VK_COMPARE_OP_NEVER:
condition = Constant(t_float, false); // Never true
break;
case VK_COMPARE_OP_LESS:
condition = OpFOrdLessThan(t_bool, Constant(t_float, specialization.alpha_test_ref),
OpLoad(t_float, pointer));
break;
case VK_COMPARE_OP_EQUAL:
condition = OpFOrdEqual(t_bool, Constant(t_float, specialization.alpha_test_ref),
OpLoad(t_float, pointer));
break;
case VK_COMPARE_OP_LESS_OR_EQUAL:
condition = OpFOrdLessThanEqual(
t_bool, Constant(t_float, specialization.alpha_test_ref), OpLoad(t_float, pointer));
break;
case VK_COMPARE_OP_GREATER:
// Note: requires "Equal" to properly work for ssbu. perhaps a precision issue
condition = OpFOrdGreaterThanEqual(
t_bool, Constant(t_float, specialization.alpha_test_ref), OpLoad(t_float, pointer));
break;
case VK_COMPARE_OP_NOT_EQUAL:
// Note: not accurate when tested against a unit test
// TODO: confirm if used by games
condition = OpFOrdNotEqual(t_bool, Constant(t_float, specialization.alpha_test_ref),
OpLoad(t_float, pointer));
break;
case VK_COMPARE_OP_GREATER_OR_EQUAL:
condition = OpFOrdGreaterThanEqual(
t_bool, Constant(t_float, specialization.alpha_test_ref), OpLoad(t_float, pointer));
break;
case VK_COMPARE_OP_ALWAYS:
condition = Constant(t_bool, true); // Always true
break;
default:
LOG_WARNING(Render_Vulkan, "Unimplemented alpha test function");
condition = Constant(t_bool, true); // Always true
break;
}
OpBranchConditional(condition, true_label, skip_label);
AddLabel(true_label);
OpKill();
AddLabel(skip_label);
}
void PreExit() {
if (stage == ShaderType::Vertex && specialization.ndc_minus_one_to_one) {
const u32 position_index = out_indices.position.value();
@ -2097,8 +2146,6 @@ private:
UNIMPLEMENTED_IF_MSG(header.ps.omap.sample_mask != 0,
"Sample mask write is unimplemented");
// TODO(Rodrigo): Alpha testing
// Write the color outputs using the data in the shader registers, disabled
// rendertargets/components are skipped in the register assignment.
u32 current_reg = 0;
@ -2110,6 +2157,9 @@ private:
}
const Id pointer = AccessElement(t_out_float, frag_colors[rt], component);
OpStore(pointer, SafeGetRegister(current_reg));
if (specialization.alpha_test_enabled && component == 3) {
AlphaTest(pointer);
}
++current_reg;
}
}

@ -95,6 +95,9 @@ struct Specialization final {
std::bitset<Maxwell::NumVertexAttributes> enabled_attributes;
std::array<Maxwell::VertexAttribute::Type, Maxwell::NumVertexAttributes> attribute_types{};
bool ndc_minus_one_to_one{};
bool alpha_test_enabled{};
float alpha_test_ref{};
u8 alpha_test_func{};
};
// Old gcc versions don't consider this trivially copyable.
// static_assert(std::is_trivially_copyable_v<Specialization>);