Method DrawPrimitive

GTE/Graphics/GL46/GL46Engine.cpp:173–250

}

uint64_t GL46Engine::DrawPrimitive(VertexBuffer const* vbuffer, IndexBuffer const* ibuffer)
{
    uint32_t numActiveVertices = vbuffer->GetNumActiveElements();
    uint32_t vertexOffset = vbuffer->GetOffset();

    uint32_t numActiveIndices = ibuffer->GetNumActiveIndices();
    uint32_t indexSize = ibuffer->GetElementSize();
    GLenum indexType = (indexSize == 4 ? GL_UNSIGNED_INT : GL_UNSIGNED_SHORT);

    GLenum topology = 0;
    uint32_t type = ibuffer->GetPrimitiveType();
    switch (type)
    {
    case IP_POLYPOINT:
        topology = GL_POINTS;
        break;
    case IP_POLYSEGMENT_DISJOINT:
        topology = GL_LINES;
        break;
    case IP_POLYSEGMENT_CONTIGUOUS:
        topology = GL_LINE_STRIP;
        break;
    case IP_TRIMESH:
        topology = GL_TRIANGLES;
        break;
    case IP_TRISTRIP:
        topology = GL_TRIANGLE_STRIP;
        break;
    case IP_POLYSEGMENT_DISJOINT_ADJ:
        topology = GL_LINES_ADJACENCY;
        break;
    case IP_POLYSEGMENT_CONTIGUOUS_ADJ:
        topology = GL_LINE_STRIP_ADJACENCY;
        break;
    case IP_TRIMESH_ADJ:
        topology = GL_TRIANGLES_ADJACENCY;
        break;
    case IP_TRISTRIP_ADJ:
        topology = GL_TRIANGLE_STRIP_ADJACENCY;
        break;
    default:
        LogError("Unknown primitive topology = " + std::to_string(type));
    }

    GLuint occlusionQuery = 0;
    uint64_t numPixelsDrawn = 0;
    if (mAllowOcclusionQuery)
    {
        occlusionQuery = BeginOcclusionQuery();
    }

    if (ibuffer->IsIndexed())
    {
        uint32_t offset = ibuffer->GetOffset();
        void const* data = reinterpret_cast<void const*>(static_cast<size_t>(indexSize) * static_cast<size_t>(offset));
        glDrawRangeElements(topology, 0, numActiveVertices - 1,
            static_cast<GLsizei>(numActiveIndices), indexType, data);
    }