maxwell3d: Implement Conditional Rendering

Conditional Rendering takes care of conditionaly clearing or drawing
depending on a set of queries. This PR implements the query checks to
stablish if things can be rendered or not.

1 files changed, 44 insertions, 0 deletions

diff --git a/src/video_core/engines/maxwell_3d.cpp b/src/video_core/engines/maxwell_3d.cpp
index 8755b8af4..20a6282ad 100644
--- a/src/video_core/engines/maxwell_3d.cpp
+++ b/src/video_core/engines/maxwell_3d.cpp
@@ -249,6 +249,10 @@ void Maxwell3D::CallMethod(const GPU::MethodCall& method_call) {
         ProcessQueryGet();
         break;
     }
+    case MAXWELL3D_REG_INDEX(condition.mode): {
+        ProcessQueryCondition();
+        break;
+    }
     case MAXWELL3D_REG_INDEX(sync_info): {
         ProcessSyncPoint();
         break;
@@ -302,6 +306,7 @@ void Maxwell3D::ProcessQueryGet() {
         result = regs.query.query_sequence;
         break;
     default:
+        result = 1;
         UNIMPLEMENTED_MSG("Unimplemented query select type {}",
                           static_cast<u32>(regs.query.query_get.select.Value()));
     }
@@ -342,6 +347,45 @@ void Maxwell3D::ProcessQueryGet() {
     }
 }
 
+void Maxwell3D::ProcessQueryCondition() {
+    const GPUVAddr condition_address{regs.condition.Address()};
+    switch (regs.condition.mode) {
+    case Regs::ConditionMode::Always: {
+        execute_on = true;
+        break;
+    }
+    case Regs::ConditionMode::Never: {
+        execute_on = false;
+        break;
+    }
+    case Regs::ConditionMode::ResNonZero: {
+        Regs::QueryCompare cmp;
+        memory_manager.ReadBlockUnsafe(condition_address, &cmp, sizeof(cmp));
+        execute_on = cmp.initial_sequence != 0U && cmp.initial_mode != 0U;
+        break;
+    }
+    case Regs::ConditionMode::Equal: {
+        Regs::QueryCompare cmp;
+        memory_manager.ReadBlockUnsafe(condition_address, &cmp, sizeof(cmp));
+        execute_on =
+            cmp.initial_sequence == cmp.current_sequence && cmp.initial_mode == cmp.current_mode;
+        break;
+    }
+    case Regs::ConditionMode::NotEqual: {
+        Regs::QueryCompare cmp;
+        memory_manager.ReadBlockUnsafe(condition_address, &cmp, sizeof(cmp));
+        execute_on =
+            cmp.initial_sequence != cmp.current_sequence || cmp.initial_mode != cmp.current_mode;
+        break;
+    }
+    default: {
+        UNIMPLEMENTED_MSG("Uninplemented Condition Mode!");
+        execute_on = true;
+        break;
+    }
+    }
+}
+
 void Maxwell3D::ProcessSyncPoint() {
     const u32 sync_point = regs.sync_info.sync_point.Value();
     const u32 increment = regs.sync_info.increment.Value();