Pica/VertexShader: Fix a bug caused due to incorrect assumptions of consecutive output register tables.

We now write create a temporary buffer for output registers and copy all of them to the actual output vertex structure after the shader has run. This is technically not necessary, but it's easier to vectorize in the future.

src/video_core/vertex_shader.cpp

@@ -72,7 +72,7 @@ struct VertexShaderState {
     u32* program_counter;
 
     const float24* input_register_table[16];
-    float24* output_register_table[7*4];
+    Math::Vec4<float24> output_registers[16];
 
     Math::Vec4<float24> temporary_registers[16];
     bool conditional_code[2];
@@ -198,8 +198,7 @@ static void ProcessShaderCode(VertexShaderState& state) {
                 src2[3] = src2[3] * float24::FromFloat32(-1);
             }
 
-            float24* dest = (instr.common.dest.Value() < 0x08) ? state.output_register_table[4*instr.common.dest.Value().GetIndex()]
-                        : (instr.common.dest.Value() < 0x10) ? dummy_vec4_float24
+            float24* dest = (instr.common.dest.Value() < 0x10) ? &state.output_registers[instr.common.dest.Value().GetIndex()][0]
                         : (instr.common.dest.Value() < 0x20) ? &state.temporary_registers[instr.common.dest.Value().GetIndex()][0]
                         : dummy_vec4_float24;
 
@@ -409,8 +408,7 @@ static void ProcessShaderCode(VertexShaderState& state) {
                     src3[3] = src3[3] * float24::FromFloat32(-1);
                 }
 
-                float24* dest = (instr.mad.dest.Value() < 0x08) ? state.output_register_table[4*instr.mad.dest.Value().GetIndex()]
-                            : (instr.mad.dest.Value() < 0x10) ? dummy_vec4_float24
+                float24* dest = (instr.mad.dest.Value() < 0x10) ? &state.output_registers[instr.mad.dest.Value().GetIndex()][0]
                             : (instr.mad.dest.Value() < 0x20) ? &state.temporary_registers[instr.mad.dest.Value().GetIndex()][0]
                             : dummy_vec4_float24;
 
@@ -587,12 +585,18 @@ OutputVertex RunShader(const InputVertex& input, int num_attributes) {
     if(num_attributes > 14) state.input_register_table[attribute_register_map.attribute14_register] = &input.attr[14].x;
     if(num_attributes > 15) state.input_register_table[attribute_register_map.attribute15_register] = &input.attr[15].x;
 
-    // Setup output register table
-    OutputVertex ret;
-    // Zero output so that attributes which aren't output won't have denormals in them, which will
-    // slow us down later.
-    memset(&ret, 0, sizeof(ret));
+    state.conditional_code[0] = false;
+    state.conditional_code[1] = false;
+
+    ProcessShaderCode(state);
+    DebugUtils::DumpShader(shader_memory.data(), state.debug.max_offset, swizzle_data.data(),
+                           state.debug.max_opdesc_id, registers.vs_main_offset,
+                           registers.vs_output_attributes);
 
+    // Setup output data
+    OutputVertex ret;
+    // TODO(neobrain): Under some circumstances, up to 16 attributes may be output. We need to
+    // figure out what those circumstances are and enable the remaining outputs then.
     for (int i = 0; i < 7; ++i) {
         const auto& output_register_map = registers.vs_output_attributes[i];
 
@@ -601,18 +605,18 @@ OutputVertex RunShader(const InputVertex& input, int num_attributes) {
             output_register_map.map_z, output_register_map.map_w
         };
 
-        for (int comp = 0; comp < 4; ++comp)
-            state.output_register_table[4*i+comp] = ((float24*)&ret) + semantics[comp];
+        for (int comp = 0; comp < 4; ++comp) {
+            float24* out = ((float24*)&ret) + semantics[comp];
+            if (semantics[comp] != Regs::VSOutputAttributes::INVALID) {
+                *out = state.output_registers[i][comp];
+            } else {
+                // Zero output so that attributes which aren't output won't have denormals in them,
+                // which would slow us down later.
+                memset(out, 0, sizeof(*out));
+            }
+        }
     }
 
-    state.conditional_code[0] = false;
-    state.conditional_code[1] = false;
-
-    ProcessShaderCode(state);
-    DebugUtils::DumpShader(shader_memory.data(), state.debug.max_offset, swizzle_data.data(),
-                           state.debug.max_opdesc_id, registers.vs_main_offset,
-                           registers.vs_output_attributes);
-
     LOG_TRACE(Render_Software, "Output vertex: pos (%.2f, %.2f, %.2f, %.2f), col(%.2f, %.2f, %.2f, %.2f), tc0(%.2f, %.2f)",
         ret.pos.x.ToFloat32(), ret.pos.y.ToFloat32(), ret.pos.z.ToFloat32(), ret.pos.w.ToFloat32(),
         ret.color.x.ToFloat32(), ret.color.y.ToFloat32(), ret.color.z.ToFloat32(), ret.color.w.ToFloat32(),