Ubershaders: Support per-pixel lighting

1 files changed, 176 insertions, 0 deletions

diff --git a/Source/Core/VideoCommon/UberShaderCommon.cpp b/Source/Core/VideoCommon/UberShaderCommon.cpp
index c6f5167b3c..58e33e5942 100644
--- a/Source/Core/VideoCommon/UberShaderCommon.cpp
+++ b/Source/Core/VideoCommon/UberShaderCommon.cpp
@@ -3,7 +3,9 @@
 // Refer to the license.txt file included.
 
 #include "VideoCommon/UberShaderCommon.h"
+#include "VideoCommon/NativeVertexFormat.h"
 #include "VideoCommon/VideoConfig.h"
+#include "VideoCommon/XFMemory.h"
 
 namespace UberShader
 {
@@ -24,4 +26,178 @@ void WriteUberShaderCommonHeader(ShaderCode& out, APIType api_type,
               "}\n\n");
   }
 }
+
+void WriteLightingFunction(ShaderCode& out)
+{
+  // ==============================================
+  // Lighting channel calculation helper
+  // ==============================================
+  out.Write("int4 CalculateLighting(uint index, uint attnfunc, uint diffusefunc, float3 pos, "
+            "float3 normal) {\n"
+            "  float3 ldir, h, cosAttn, distAttn;\n"
+            "  float dist, dist2, attn;\n"
+            "\n"
+            "  switch (attnfunc) {\n");
+  out.Write("  case %uu: // LIGNTATTN_NONE\n", LIGHTATTN_NONE);
+  out.Write("  case %uu: // LIGHTATTN_DIR\n", LIGHTATTN_DIR);
+  out.Write("    ldir = normalize(" I_LIGHTS "[index].pos.xyz - pos.xyz);\n"
+            "    attn = 1.0;\n"
+            "    if (length(ldir) == 0.0)\n"
+            "      ldir = normal;\n"
+            "    break;\n\n");
+  out.Write("  case %uu: // LIGHTATTN_SPEC\n", LIGHTATTN_SPEC);
+  out.Write("    ldir = normalize(" I_LIGHTS "[index].pos.xyz - pos.xyz);\n"
+            "    attn = (dot(normal, ldir) >= 0.0) ? max(0.0, dot(normal, " I_LIGHTS
+            "[index].dir.xyz)) : 0.0;\n"
+            "    cosAttn = " I_LIGHTS "[index].cosatt.xyz;\n");
+  out.Write("    if (diffusefunc == %uu) // LIGHTDIF_NONE\n", LIGHTDIF_NONE);
+  out.Write("      distAttn = " I_LIGHTS "[index].distatt.xyz;\n"
+            "    else\n"
+            "      distAttn = normalize(" I_LIGHTS "[index].distatt.xyz);\n"
+            "    attn = max(0.0, dot(cosAttn, float3(1.0, attn, attn*attn))) / dot(distAttn, "
+            "float3(1.0, attn, attn*attn));\n"
+            "    break;\n\n");
+  out.Write("  case %uu: // LIGHTATTN_SPOT\n", LIGHTATTN_SPOT);
+  out.Write("    ldir = " I_LIGHTS "[index].pos.xyz - pos.xyz;\n"
+            "    dist2 = dot(ldir, ldir);\n"
+            "    dist = sqrt(dist2);\n"
+            "    ldir = ldir / dist;\n"
+            "    attn = max(0.0, dot(ldir, " I_LIGHTS "[index].dir.xyz));\n"
+            "    attn = max(0.0, " I_LIGHTS "[index].cosatt.x + " I_LIGHTS
+            "[index].cosatt.y * attn + " I_LIGHTS "[index].cosatt.z * attn * attn) / dot(" I_LIGHTS
+            "[index].distatt.xyz, float3(1.0, dist, dist2));\n"
+            "    break;\n\n");
+  out.Write("  default:\n"
+            "    attn = 1.0;\n"
+            "    ldir = normal;\n"
+            "    break;\n"
+            "  }\n"
+            "\n"
+            "  switch (diffusefunc) {\n");
+  out.Write("  case %uu: // LIGHTDIF_NONE\n", LIGHTDIF_NONE);
+  out.Write("    return int4(round(attn * float4(" I_LIGHTS "[index].color)));\n\n");
+  out.Write("  case %uu: // LIGHTDIF_SIGN\n", LIGHTDIF_SIGN);
+  out.Write("    return int4(round(attn * dot(ldir, normal) * float4(" I_LIGHTS
+            "[index].color)));\n\n");
+  out.Write("  case %uu: // LIGHTDIF_CLAMP\n", LIGHTDIF_CLAMP);
+  out.Write("    return int4(round(attn * max(0.0, dot(ldir, normal)) * float4(" I_LIGHTS
+            "[index].color)));\n\n");
+  out.Write("  default:\n"
+            "    return int4(0, 0, 0, 0);\n"
+            "  }\n"
+            "}\n\n");
+}
+
+void WriteVertexLighting(ShaderCode& out, APIType api_type, const char* world_pos_var,
+                         const char* normal_var, const char* in_color_0_var,
+                         const char* in_color_1_var, const char* out_color_0_var,
+                         const char* out_color_1_var)
+{
+  out.Write("// Lighting\n");
+  out.Write("%sfor (uint chan = 0u; chan < xfmem_numColorChans; chan++) {\n",
+            api_type == APIType::D3D ? "[loop] " : "");
+  out.Write("  uint colorreg = xfmem_color(chan);\n"
+            "  uint alphareg = xfmem_alpha(chan);\n"
+            "  int4 mat = " I_MATERIALS "[chan + 2u]; \n"
+            "  int4 lacc = int4(255, 255, 255, 255);\n"
+            "\n");
+
+  out.Write("  if (%s != 0u) {\n", BitfieldExtract("colorreg", LitChannel().matsource).c_str());
+  out.Write("    if ((components & (%uu << chan)) != 0u) // VB_HAS_COL0\n", VB_HAS_COL0);
+  out.Write("      mat.xyz = int3(round(((chan == 0u) ? %s.xyz : %s.xyz) * 255.0));\n",
+            in_color_0_var, in_color_1_var);
+  out.Write("    else if ((components & %uu) != 0u) // VB_HAS_COLO0\n", VB_HAS_COL0);
+  out.Write("      mat.xyz = int3(round(%s.xyz * 255.0));\n", in_color_0_var);
+  out.Write("    else\n"
+            "      mat.xyz = int3(255, 255, 255);\n"
+            "  }\n"
+            "\n");
+
+  out.Write("  if (%s != 0u) {\n", BitfieldExtract("alphareg", LitChannel().matsource).c_str());
+  out.Write("    if ((components & (%uu << chan)) != 0u) // VB_HAS_COL0\n", VB_HAS_COL0);
+  out.Write("      mat.w = int(round(((chan == 0u) ? %s.w : %s.w) * 255.0));\n", in_color_0_var,
+            in_color_1_var);
+  out.Write("    else if ((components & %uu) != 0u) // VB_HAS_COLO0\n", VB_HAS_COL0);
+  out.Write("      mat.w = int(round(%s.w * 255.0));\n", in_color_0_var);
+  out.Write("    else\n"
+            "      mat.w = 255;\n"
+            "  } else {\n"
+            "    mat.w = " I_MATERIALS " [chan + 2u].w;\n"
+            "  }\n"
+            "\n");
+
+  out.Write("  if (%s != 0u) {\n",
+            BitfieldExtract("colorreg", LitChannel().enablelighting).c_str());
+  out.Write("    if (%s != 0u) {\n", BitfieldExtract("colorreg", LitChannel().ambsource).c_str());
+  out.Write("      if ((components & (%uu << chan)) != 0u) // VB_HAS_COL0\n", VB_HAS_COL0);
+  out.Write("        lacc.xyz = int3(round(((chan == 0u) ? %s.xyz : %s.xyz) * 255.0));\n",
+            in_color_0_var, in_color_1_var);
+  out.Write("      else if ((components & %uu) != 0u) // VB_HAS_COLO0\n", VB_HAS_COL0);
+  out.Write("        lacc.xyz = int3(round(%s.xyz * 255.0));\n", in_color_0_var);
+  out.Write("      else\n"
+            "        lacc.xyz = int3(255, 255, 255);\n"
+            "    } else {\n"
+            "      lacc.xyz = " I_MATERIALS " [chan].xyz;\n"
+            "    }\n"
+            "\n");
+  out.Write("    uint light_mask = %s | (%s << 4u);\n",
+            BitfieldExtract("colorreg", LitChannel().lightMask0_3).c_str(),
+            BitfieldExtract("colorreg", LitChannel().lightMask4_7).c_str());
+  out.Write("    uint attnfunc = %s;\n",
+            BitfieldExtract("colorreg", LitChannel().attnfunc).c_str());
+  out.Write("    uint diffusefunc = %s;\n",
+            BitfieldExtract("colorreg", LitChannel().diffusefunc).c_str());
+  out.Write(
+      "    for (uint light_index = 0u; light_index < 8u; light_index++) {\n"
+      "      if ((light_mask & (1u << light_index)) != 0u)\n"
+      "        lacc.xyz += CalculateLighting(light_index, attnfunc, diffusefunc, %s, %s).xyz;\n",
+      world_pos_var, normal_var);
+  out.Write("    }\n"
+            "  }\n"
+            "\n");
+
+  out.Write("  if (%s != 0u) {\n",
+            BitfieldExtract("alphareg", LitChannel().enablelighting).c_str());
+  out.Write("    if (%s != 0u) {\n", BitfieldExtract("alphareg", LitChannel().ambsource).c_str());
+  out.Write("      if ((components & (%uu << chan)) != 0u) // VB_HAS_COL0\n", VB_HAS_COL0);
+  out.Write("        lacc.w = int(round(((chan == 0u) ? %s.w : %s.w) * 255.0));\n", in_color_0_var,
+            in_color_1_var);
+  out.Write("      else if ((components & %uu) != 0u) // VB_HAS_COLO0\n", VB_HAS_COL0);
+  out.Write("        lacc.w = int(round(%s.w * 255.0));\n", in_color_0_var);
+  out.Write("      else\n"
+            "        lacc.w = 255;\n"
+            "    } else {\n"
+            "      lacc.w = " I_MATERIALS " [chan].w;\n"
+            "    }\n"
+            "\n");
+  out.Write("    uint light_mask = %s | (%s << 4u);\n",
+            BitfieldExtract("alphareg", LitChannel().lightMask0_3).c_str(),
+            BitfieldExtract("alphareg", LitChannel().lightMask4_7).c_str());
+  out.Write("    uint attnfunc = %s;\n",
+            BitfieldExtract("alphareg", LitChannel().attnfunc).c_str());
+  out.Write("    uint diffusefunc = %s;\n",
+            BitfieldExtract("alphareg", LitChannel().diffusefunc).c_str());
+  out.Write("    for (uint light_index = 0u; light_index < 8u; light_index++) {\n\n"
+            "      if ((light_mask & (1u << light_index)) != 0u)\n\n"
+            "        lacc.w += CalculateLighting(light_index, attnfunc, diffusefunc, %s, %s).w;\n",
+            world_pos_var, normal_var);
+  out.Write("    }\n"
+            "  }\n"
+            "\n");
+
+  out.Write("  lacc = clamp(lacc, 0, 255);\n"
+            "\n"
+            "  // Hopefully GPUs that can support dynamic indexing will optimize this.\n"
+            "  float4 lit_color = float4((mat * (lacc + (lacc >> 7))) >> 8) / 255.0;\n"
+            "  switch (chan) {\n"
+            "  case 0u: %s = lit_color; break;\n",
+            out_color_0_var);
+  out.Write("  case 1u: %s = lit_color; break;\n", out_color_1_var);
+  out.Write("  }\n"
+            "}\n"
+            "\n");
+
+  out.Write("if (xfmem_numColorChans < 2u && (components & %uu) == 0u)\n", VB_HAS_COL1);
+  out.Write("  %s = %s;\n\n", out_color_1_var, out_color_0_var);
+}
 }