citra/src/video_core/primitive_assembly.cpp

// Copyright 2014 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.

#include "pica.h"
#include "primitive_assembly.h"
#include "vertex_shader.h"

#include "common/logging/log.h"
#include "video_core/debug_utils/debug_utils.h"

namespace Pica {

template<typename VertexType>
PrimitiveAssembler<VertexType>::PrimitiveAssembler(Regs::TriangleTopology topology)
    : topology(topology), buffer_index(0) {
}

template<typename VertexType>
void PrimitiveAssembler<VertexType>::SubmitVertex(VertexType& vtx, TriangleHandler triangle_handler)
{
    switch (topology) {
        case Regs::TriangleTopology::List:
        case Regs::TriangleTopology::ListIndexed:
            if (buffer_index < 2) {
                buffer[buffer_index++] = vtx;
            } else {
                buffer_index = 0;

                triangle_handler(buffer[0], buffer[1], vtx);
            }
            break;

        case Regs::TriangleTopology::Strip:
        case Regs::TriangleTopology::Fan:
            if (strip_ready) {
                // TODO: Should be "buffer[0], buffer[1], vtx" instead!
                // Not quite sure why we need this order for things to show up properly.
                // Maybe a bug in the rasterizer?
                triangle_handler(buffer[1], buffer[0], vtx);
            }
            buffer[buffer_index] = vtx;

            if (topology == Regs::TriangleTopology::Strip) {
                strip_ready |= (buffer_index == 1);
                buffer_index = !buffer_index;
            } else if (topology == Regs::TriangleTopology::Fan) {
                buffer_index = 1;
                strip_ready = true;
            }
            break;

        default:
            LOG_ERROR(HW_GPU, "Unknown triangle topology %x:", (int)topology);
            break;
    }
}

// explicitly instantiate use cases
template
struct PrimitiveAssembler<VertexShader::OutputVertex>;
template
struct PrimitiveAssembler<DebugUtils::GeometryDumper::Vertex>;

} // namespace