1 files changed, 228 insertions, 0 deletions

diff --git a/src/video_core/swrasterizer/texturing.cpp b/src/video_core/swrasterizer/texturing.cpp
new file mode 100644
index 000000000..eb18e4ba4
--- /dev/null
+++ b/src/video_core/swrasterizer/texturing.cpp
@@ -0,0 +1,228 @@
+// Copyright 2017 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+
+#include "common/assert.h"
+#include "common/common_types.h"
+#include "common/math_util.h"
+#include "common/vector_math.h"
+#include "video_core/regs_texturing.h"
+#include "video_core/swrasterizer/texturing.h"
+
+namespace Pica {
+namespace Rasterizer {
+
+using TevStageConfig = TexturingRegs::TevStageConfig;
+
+int GetWrappedTexCoord(TexturingRegs::TextureConfig::WrapMode mode, int val, unsigned size) {
+    switch (mode) {
+    case TexturingRegs::TextureConfig::ClampToEdge:
+        val = std::max(val, 0);
+        val = std::min(val, (int)size - 1);
+        return val;
+
+    case TexturingRegs::TextureConfig::ClampToBorder:
+        return val;
+
+    case TexturingRegs::TextureConfig::Repeat:
+        return (int)((unsigned)val % size);
+
+    case TexturingRegs::TextureConfig::MirroredRepeat: {
+        unsigned int coord = ((unsigned)val % (2 * size));
+        if (coord >= size)
+            coord = 2 * size - 1 - coord;
+        return (int)coord;
+    }
+
+    default:
+        LOG_ERROR(HW_GPU, "Unknown texture coordinate wrapping mode %x", (int)mode);
+        UNIMPLEMENTED();
+        return 0;
+    }
+};
+
+Math::Vec3<u8> GetColorModifier(TevStageConfig::ColorModifier factor,
+                                const Math::Vec4<u8>& values) {
+    using ColorModifier = TevStageConfig::ColorModifier;
+
+    switch (factor) {
+    case ColorModifier::SourceColor:
+        return values.rgb();
+
+    case ColorModifier::OneMinusSourceColor:
+        return (Math::Vec3<u8>(255, 255, 255) - values.rgb()).Cast<u8>();
+
+    case ColorModifier::SourceAlpha:
+        return values.aaa();
+
+    case ColorModifier::OneMinusSourceAlpha:
+        return (Math::Vec3<u8>(255, 255, 255) - values.aaa()).Cast<u8>();
+
+    case ColorModifier::SourceRed:
+        return values.rrr();
+
+    case ColorModifier::OneMinusSourceRed:
+        return (Math::Vec3<u8>(255, 255, 255) - values.rrr()).Cast<u8>();
+
+    case ColorModifier::SourceGreen:
+        return values.ggg();
+
+    case ColorModifier::OneMinusSourceGreen:
+        return (Math::Vec3<u8>(255, 255, 255) - values.ggg()).Cast<u8>();
+
+    case ColorModifier::SourceBlue:
+        return values.bbb();
+
+    case ColorModifier::OneMinusSourceBlue:
+        return (Math::Vec3<u8>(255, 255, 255) - values.bbb()).Cast<u8>();
+    }
+};
+
+u8 GetAlphaModifier(TevStageConfig::AlphaModifier factor, const Math::Vec4<u8>& values) {
+    using AlphaModifier = TevStageConfig::AlphaModifier;
+
+    switch (factor) {
+    case AlphaModifier::SourceAlpha:
+        return values.a();
+
+    case AlphaModifier::OneMinusSourceAlpha:
+        return 255 - values.a();
+
+    case AlphaModifier::SourceRed:
+        return values.r();
+
+    case AlphaModifier::OneMinusSourceRed:
+        return 255 - values.r();
+
+    case AlphaModifier::SourceGreen:
+        return values.g();
+
+    case AlphaModifier::OneMinusSourceGreen:
+        return 255 - values.g();
+
+    case AlphaModifier::SourceBlue:
+        return values.b();
+
+    case AlphaModifier::OneMinusSourceBlue:
+        return 255 - values.b();
+    }
+};
+
+Math::Vec3<u8> ColorCombine(TevStageConfig::Operation op, const Math::Vec3<u8> input[3]) {
+    using Operation = TevStageConfig::Operation;
+
+    switch (op) {
+    case Operation::Replace:
+        return input[0];
+
+    case Operation::Modulate:
+        return ((input[0] * input[1]) / 255).Cast<u8>();
+
+    case Operation::Add: {
+        auto result = input[0] + input[1];
+        result.r() = std::min(255, result.r());
+        result.g() = std::min(255, result.g());
+        result.b() = std::min(255, result.b());
+        return result.Cast<u8>();
+    }
+
+    case Operation::AddSigned: {
+        // TODO(bunnei): Verify that the color conversion from (float) 0.5f to
+        // (byte) 128 is correct
+        auto result =
+            input[0].Cast<int>() + input[1].Cast<int>() - Math::MakeVec<int>(128, 128, 128);
+        result.r() = MathUtil::Clamp<int>(result.r(), 0, 255);
+        result.g() = MathUtil::Clamp<int>(result.g(), 0, 255);
+        result.b() = MathUtil::Clamp<int>(result.b(), 0, 255);
+        return result.Cast<u8>();
+    }
+
+    case Operation::Lerp:
+        return ((input[0] * input[2] +
+                 input[1] * (Math::MakeVec<u8>(255, 255, 255) - input[2]).Cast<u8>()) /
+                255)
+            .Cast<u8>();
+
+    case Operation::Subtract: {
+        auto result = input[0].Cast<int>() - input[1].Cast<int>();
+        result.r() = std::max(0, result.r());
+        result.g() = std::max(0, result.g());
+        result.b() = std::max(0, result.b());
+        return result.Cast<u8>();
+    }
+
+    case Operation::MultiplyThenAdd: {
+        auto result = (input[0] * input[1] + 255 * input[2].Cast<int>()) / 255;
+        result.r() = std::min(255, result.r());
+        result.g() = std::min(255, result.g());
+        result.b() = std::min(255, result.b());
+        return result.Cast<u8>();
+    }
+
+    case Operation::AddThenMultiply: {
+        auto result = input[0] + input[1];
+        result.r() = std::min(255, result.r());
+        result.g() = std::min(255, result.g());
+        result.b() = std::min(255, result.b());
+        result = (result * input[2].Cast<int>()) / 255;
+        return result.Cast<u8>();
+    }
+    case Operation::Dot3_RGB: {
+        // Not fully accurate.  Worst case scenario seems to yield a +/-3 error.  Some HW results
+        // indicate that the per-component computation can't have a higher precision than 1/256,
+        // while dot3_rgb((0x80,g0,b0), (0x7F,g1,b1)) and dot3_rgb((0x80,g0,b0), (0x80,g1,b1)) give
+        // different results.
+        int result = ((input[0].r() * 2 - 255) * (input[1].r() * 2 - 255) + 128) / 256 +
+                     ((input[0].g() * 2 - 255) * (input[1].g() * 2 - 255) + 128) / 256 +
+                     ((input[0].b() * 2 - 255) * (input[1].b() * 2 - 255) + 128) / 256;
+        result = std::max(0, std::min(255, result));
+        return {(u8)result, (u8)result, (u8)result};
+    }
+    default:
+        LOG_ERROR(HW_GPU, "Unknown color combiner operation %d", (int)op);
+        UNIMPLEMENTED();
+        return {0, 0, 0};
+    }
+};
+
+u8 AlphaCombine(TevStageConfig::Operation op, const std::array<u8, 3>& input) {
+    switch (op) {
+        using Operation = TevStageConfig::Operation;
+    case Operation::Replace:
+        return input[0];
+
+    case Operation::Modulate:
+        return input[0] * input[1] / 255;
+
+    case Operation::Add:
+        return std::min(255, input[0] + input[1]);
+
+    case Operation::AddSigned: {
+        // TODO(bunnei): Verify that the color conversion from (float) 0.5f to (byte) 128 is correct
+        auto result = static_cast<int>(input[0]) + static_cast<int>(input[1]) - 128;
+        return static_cast<u8>(MathUtil::Clamp<int>(result, 0, 255));
+    }
+
+    case Operation::Lerp:
+        return (input[0] * input[2] + input[1] * (255 - input[2])) / 255;
+
+    case Operation::Subtract:
+        return std::max(0, (int)input[0] - (int)input[1]);
+
+    case Operation::MultiplyThenAdd:
+        return std::min(255, (input[0] * input[1] + 255 * input[2]) / 255);
+
+    case Operation::AddThenMultiply:
+        return (std::min(255, (input[0] + input[1])) * input[2]) / 255;
+
+    default:
+        LOG_ERROR(HW_GPU, "Unknown alpha combiner operation %d", (int)op);
+        UNIMPLEMENTED();
+        return 0;
+    }
+};
+
+} // namespace Rasterizer
+} // namespace Pica