From e4f5ec6272016dd34afe4e8901a9e8027324ba21 Mon Sep 17 00:00:00 2001
From: Tony Wasserka <neobrainx@gmail.com>
Date: Thu, 12 Mar 2015 14:18:46 +0100
Subject: [PATCH] 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 | 44 +++++++++++++++++---------------
 1 file changed, 24 insertions(+), 20 deletions(-)

diff --git a/src/video_core/vertex_shader.cpp b/src/video_core/vertex_shader.cpp
index 4eb3e743e6..e8d865172c 100644
--- a/src/video_core/vertex_shader.cpp
+++ b/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(),