1 files changed, 163 insertions, 0 deletions

diff --git a/src/video_core/shader/shader.h b/src/video_core/shader/shader.h
new file mode 100644
index 000000000..38c00768d
--- /dev/null
+++ b/src/video_core/shader/shader.h
@@ -0,0 +1,163 @@
+// Copyright 2015 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <boost/container/static_vector.hpp>
+#include <nihstro/shader_binary.h>
+
+#include "common/common_funcs.h"
+#include "common/common_types.h"
+#include "common/vector_math.h"
+
+#include "video_core/pica.h"
+
+using nihstro::RegisterType;
+using nihstro::SourceRegister;
+using nihstro::DestRegister;
+
+namespace Pica {
+
+namespace Shader {
+
+struct InputVertex {
+    Math::Vec4<float24> attr[16];
+};
+
+struct OutputVertex {
+    OutputVertex() = default;
+
+    // VS output attributes
+    Math::Vec4<float24> pos;
+    Math::Vec4<float24> dummy; // quaternions (not implemented, yet)
+    Math::Vec4<float24> color;
+    Math::Vec2<float24> tc0;
+    Math::Vec2<float24> tc1;
+    float24 pad[6];
+    Math::Vec2<float24> tc2;
+
+    // Padding for optimal alignment
+    float24 pad2[4];
+
+    // Attributes used to store intermediate results
+
+    // position after perspective divide
+    Math::Vec3<float24> screenpos;
+    float24 pad3;
+
+    // Linear interpolation
+    // factor: 0=this, 1=vtx
+    void Lerp(float24 factor, const OutputVertex& vtx) {
+        pos = pos * factor + vtx.pos * (float24::FromFloat32(1) - factor);
+
+        // TODO: Should perform perspective correct interpolation here...
+        tc0 = tc0 * factor + vtx.tc0 * (float24::FromFloat32(1) - factor);
+        tc1 = tc1 * factor + vtx.tc1 * (float24::FromFloat32(1) - factor);
+        tc2 = tc2 * factor + vtx.tc2 * (float24::FromFloat32(1) - factor);
+
+        screenpos = screenpos * factor + vtx.screenpos * (float24::FromFloat32(1) - factor);
+
+        color = color * factor + vtx.color * (float24::FromFloat32(1) - factor);
+    }
+
+    // Linear interpolation
+    // factor: 0=v0, 1=v1
+    static OutputVertex Lerp(float24 factor, const OutputVertex& v0, const OutputVertex& v1) {
+        OutputVertex ret = v0;
+        ret.Lerp(factor, v1);
+        return ret;
+    }
+};
+static_assert(std::is_pod<OutputVertex>::value, "Structure is not POD");
+static_assert(sizeof(OutputVertex) == 32 * sizeof(float), "OutputVertex has invalid size");
+
+/**
+ * This structure contains the state information that needs to be unique for a shader unit. The 3DS
+ * has four shader units that process shaders in parallel. At the present, Citra only implements a
+ * single shader unit that processes all shaders serially. Putting the state information in a struct
+ * here will make it easier for us to parallelize the shader processing later.
+ */
+struct UnitState {
+    // The registers are accessed by the shader JIT using SSE instructions, and are therefore
+    // required to be 16-byte aligned.
+    Math::Vec4<float24> MEMORY_ALIGNED16(input_registers[16]);
+    Math::Vec4<float24> MEMORY_ALIGNED16(output_registers[16]);
+    Math::Vec4<float24> MEMORY_ALIGNED16(temporary_registers[16]);
+
+    u32 program_counter;
+    bool conditional_code[2];
+
+    // Two Address registers and one loop counter
+    // TODO: How many bits do these actually have?
+    s32 address_registers[3];
+
+    enum {
+        INVALID_ADDRESS = 0xFFFFFFFF
+    };
+
+    struct CallStackElement {
+        u32 final_address;  // Address upon which we jump to return_address
+        u32 return_address; // Where to jump when leaving scope
+        u8 repeat_counter;  // How often to repeat until this call stack element is removed
+        u8 loop_increment;  // Which value to add to the loop counter after an iteration
+                            // TODO: Should this be a signed value? Does it even matter?
+        u32 loop_address;   // The address where we'll return to after each loop iteration
+    };
+
+    // TODO: Is there a maximal size for this?
+    boost::container::static_vector<CallStackElement, 16> call_stack;
+
+    struct {
+        u32 max_offset; // maximum program counter ever reached
+        u32 max_opdesc_id; // maximum swizzle pattern index ever used
+    } debug;
+
+    static int InputOffset(const SourceRegister& reg) {
+        switch (reg.GetRegisterType()) {
+        case RegisterType::Input:
+            return (int)offsetof(UnitState, input_registers) + reg.GetIndex()*sizeof(Math::Vec4<float24>);
+
+        case RegisterType::Temporary:
+            return (int)offsetof(UnitState, temporary_registers) + reg.GetIndex()*sizeof(Math::Vec4<float24>);
+
+        default:
+            UNREACHABLE();
+            return 0;
+        }
+    }
+
+    static int OutputOffset(const DestRegister& reg) {
+        switch (reg.GetRegisterType()) {
+        case RegisterType::Output:
+            return (int)offsetof(UnitState, output_registers) + reg.GetIndex()*sizeof(Math::Vec4<float24>);
+
+        case RegisterType::Temporary:
+            return (int)offsetof(UnitState, temporary_registers) + reg.GetIndex()*sizeof(Math::Vec4<float24>);
+
+        default:
+            UNREACHABLE();
+            return 0;
+        }
+    }
+};
+
+/**
+ * Performs any shader unit setup that only needs to happen once per shader (as opposed to once per
+ * vertex, which would happen within the `Run` function).
+ * @param state Shader unit state, must be setup per shader and per shader unit
+ */
+void Setup(UnitState& state);
+
+/**
+ * Runs the currently setup shader
+ * @param state Shader unit state, must be setup per shader and per shader unit
+ * @param input Input vertex into the shader
+ * @param num_attributes The number of vertex shader attributes
+ * @return The output vertex, after having been processed by the vertex shader
+ */
+OutputVertex Run(UnitState& state, const InputVertex& input, int num_attributes);
+
+} // namespace Shader
+
+} // namespace Pica