diff --git a/src/video_core/engines/maxwell_3d.h b/src/video_core/engines/maxwell_3d.h
index c8af1c6b67..0e09a7ee55 100644
--- a/src/video_core/engines/maxwell_3d.h
+++ b/src/video_core/engines/maxwell_3d.h
@@ -643,8 +643,10 @@ public:
u32 d3d_cull_mode;
ComparisonOp depth_test_func;
+ float alpha_test_ref;
+ ComparisonOp alpha_test_func;
- INSERT_PADDING_WORDS(0xB);
+ INSERT_PADDING_WORDS(0x9);
struct {
u32 separate_alpha;
diff --git a/src/video_core/renderer_opengl/gl_rasterizer.cpp b/src/video_core/renderer_opengl/gl_rasterizer.cpp
index 3daccf82f0..be51c5215f 100644
--- a/src/video_core/renderer_opengl/gl_rasterizer.cpp
+++ b/src/video_core/renderer_opengl/gl_rasterizer.cpp
@@ -570,10 +570,11 @@ void RasterizerOpenGL::DrawArrays() {
SyncBlendState();
SyncLogicOpState();
SyncCullMode();
- SyncAlphaTest();
SyncScissorTest();
+ // Alpha Testing is synced on shaders.
SyncTransformFeedback();
SyncPointState();
+ CheckAlphaTests();
// TODO(bunnei): Sync framebuffer_scale uniform here
// TODO(bunnei): Sync scissorbox uniform(s) here
@@ -1007,17 +1008,6 @@ void RasterizerOpenGL::SyncLogicOpState() {
state.logic_op.operation = MaxwellToGL::LogicOp(regs.logic_op.operation);
}
-void RasterizerOpenGL::SyncAlphaTest() {
- const auto& regs = Core::System::GetInstance().GPU().Maxwell3D().regs;
-
- // TODO(Rodrigo): Alpha testing is a legacy OpenGL feature, but it can be
- // implemented with a test+discard in fragment shaders.
- if (regs.alpha_test_enabled != 0) {
- LOG_CRITICAL(Render_OpenGL, "Alpha testing is not implemented");
- UNREACHABLE();
- }
-}
-
void RasterizerOpenGL::SyncScissorTest() {
const auto& regs = Core::System::GetInstance().GPU().Maxwell3D().regs;
@@ -1052,4 +1042,15 @@ void RasterizerOpenGL::SyncPointState() {
state.point.size = regs.point_size == 0 ? 1 : regs.point_size;
}
+void RasterizerOpenGL::CheckAlphaTests() {
+ const auto& regs = Core::System::GetInstance().GPU().Maxwell3D().regs;
+
+ if (regs.alpha_test_enabled != 0 && regs.rt_control.count > 1) {
+ LOG_CRITICAL(
+ Render_OpenGL,
+ "Alpha Testing is enabled with Multiple Render Targets, this behavior is undefined.");
+ UNREACHABLE();
+ }
+}
+
} // namespace OpenGL
diff --git a/src/video_core/renderer_opengl/gl_rasterizer.h b/src/video_core/renderer_opengl/gl_rasterizer.h
index b1f7ccc7e7..0e90a31f5e 100644
--- a/src/video_core/renderer_opengl/gl_rasterizer.h
+++ b/src/video_core/renderer_opengl/gl_rasterizer.h
@@ -162,9 +162,6 @@ private:
/// Syncs the LogicOp state to match the guest state
void SyncLogicOpState();
- /// Syncs the alpha test state to match the guest state
- void SyncAlphaTest();
-
/// Syncs the scissor test state to match the guest state
void SyncScissorTest();
@@ -174,6 +171,9 @@ private:
/// Syncs the point state to match the guest state
void SyncPointState();
+ /// Check asserts for alpha testing.
+ void CheckAlphaTests();
+
bool has_ARB_direct_state_access = false;
bool has_ARB_multi_bind = false;
bool has_ARB_separate_shader_objects = false;
diff --git a/src/video_core/renderer_opengl/gl_shader_decompiler.cpp b/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
index d36f190b7d..7a019fc860 100644
--- a/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
+++ b/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
@@ -1266,9 +1266,29 @@ private:
ASSERT_MSG(header.ps.omap.sample_mask == 0, "Samplemask write is unimplemented");
+ shader.AddLine("if (alpha_test[0] != 0) {");
+ ++shader.scope;
+ // We start on the register containing the alpha value in the first RT.
+ u32 current_reg = 3;
+ for (u32 render_target = 0; render_target < Maxwell3D::Regs::NumRenderTargets;
+ ++render_target) {
+ // TODO(Blinkhawk): verify the behavior of alpha testing on hardware when
+ // multiple render targets are used.
+ if (header.ps.IsColorComponentOutputEnabled(render_target, 0) ||
+ header.ps.IsColorComponentOutputEnabled(render_target, 1) ||
+ header.ps.IsColorComponentOutputEnabled(render_target, 2) ||
+ header.ps.IsColorComponentOutputEnabled(render_target, 3)) {
+ shader.AddLine(fmt::format("if (!AlphaFunc({})) discard;",
+ regs.GetRegisterAsFloat(current_reg)));
+ current_reg += 4;
+ }
+ }
+ --shader.scope;
+ shader.AddLine('}');
+
// Write the color outputs using the data in the shader registers, disabled
// rendertargets/components are skipped in the register assignment.
- u32 current_reg = 0;
+ current_reg = 0;
for (u32 render_target = 0; render_target < Maxwell3D::Regs::NumRenderTargets;
++render_target) {
// TODO(Subv): Figure out how dual-source blending is configured in the Switch.
@@ -3516,7 +3536,7 @@ private:
// Declarations
std::set<std::string> declr_predicates;
-}; // namespace Decompiler
+}; // namespace OpenGL::GLShader::Decompiler
std::string GetCommonDeclarations() {
return fmt::format("#define MAX_CONSTBUFFER_ELEMENTS {}\n",
diff --git a/src/video_core/renderer_opengl/gl_shader_gen.cpp b/src/video_core/renderer_opengl/gl_shader_gen.cpp
index ecbc9d8ed3..e883ffb1df 100644
--- a/src/video_core/renderer_opengl/gl_shader_gen.cpp
+++ b/src/video_core/renderer_opengl/gl_shader_gen.cpp
@@ -29,6 +29,7 @@ layout(std140) uniform vs_config {
vec4 viewport_flip;
uvec4 instance_id;
uvec4 flip_stage;
+ uvec4 alpha_test;
};
)";
@@ -105,6 +106,7 @@ layout (std140) uniform gs_config {
vec4 viewport_flip;
uvec4 instance_id;
uvec4 flip_stage;
+ uvec4 alpha_test;
};
void main() {
@@ -142,8 +144,33 @@ layout (std140) uniform fs_config {
vec4 viewport_flip;
uvec4 instance_id;
uvec4 flip_stage;
+ uvec4 alpha_test;
};
+bool AlphaFunc(in float value) {
+ float ref = uintBitsToFloat(alpha_test[2]);
+ switch (alpha_test[1]) {
+ case 1:
+ return false;
+ case 2:
+ return value < ref;
+ case 3:
+ return value == ref;
+ case 4:
+ return value <= ref;
+ case 5:
+ return value > ref;
+ case 6:
+ return value != ref;
+ case 7:
+ return value >= ref;
+ case 8:
+ return true;
+ default:
+ return false;
+ }
+}
+
void main() {
exec_fragment();
}
@@ -152,4 +179,4 @@ void main() {
out += program.first;
return {out, program.second};
}
-} // namespace OpenGL::GLShader
\ No newline at end of file
+} // namespace OpenGL::GLShader
diff --git a/src/video_core/renderer_opengl/gl_shader_manager.cpp b/src/video_core/renderer_opengl/gl_shader_manager.cpp
index 010857ec62..8b8869ecbf 100644
--- a/src/video_core/renderer_opengl/gl_shader_manager.cpp
+++ b/src/video_core/renderer_opengl/gl_shader_manager.cpp
@@ -16,6 +16,17 @@ void MaxwellUniformData::SetFromRegs(const Maxwell3D::State::ShaderStageInfo& sh
viewport_flip[0] = regs.viewport_transform[0].scale_x < 0.0 ? -1.0f : 1.0f;
viewport_flip[1] = regs.viewport_transform[0].scale_y < 0.0 ? -1.0f : 1.0f;
+ u32 func = static_cast<u32>(regs.alpha_test_func);
+ // Normalize the gl variants of opCompare to be the same as the normal variants
+ u32 op_gl_variant_base = static_cast<u32>(Tegra::Engines::Maxwell3D::Regs::ComparisonOp::Never);
+ if (func >= op_gl_variant_base) {
+ func = func - op_gl_variant_base + 1U;
+ }
+
+ alpha_test.enabled = regs.alpha_test_enabled;
+ alpha_test.func = func;
+ alpha_test.ref = regs.alpha_test_ref;
+
// We only assign the instance to the first component of the vector, the rest is just padding.
instance_id[0] = state.current_instance;
diff --git a/src/video_core/renderer_opengl/gl_shader_manager.h b/src/video_core/renderer_opengl/gl_shader_manager.h
index b3a191cf2c..36fe1f04ce 100644
--- a/src/video_core/renderer_opengl/gl_shader_manager.h
+++ b/src/video_core/renderer_opengl/gl_shader_manager.h
@@ -22,8 +22,14 @@ struct MaxwellUniformData {
alignas(16) GLvec4 viewport_flip;
alignas(16) GLuvec4 instance_id;
alignas(16) GLuvec4 flip_stage;
+ struct alignas(16) {
+ GLuint enabled;
+ GLuint func;
+ GLfloat ref;
+ GLuint padding;
+ } alpha_test;
};
-static_assert(sizeof(MaxwellUniformData) == 48, "MaxwellUniformData structure size is incorrect");
+static_assert(sizeof(MaxwellUniformData) == 64, "MaxwellUniformData structure size is incorrect");
static_assert(sizeof(MaxwellUniformData) < 16384,
"MaxwellUniformData structure must be less than 16kb as per the OpenGL spec");