tessellatedQuad/TessellatedQuadGeomOverride.cpp

//-
// ==========================================================================
// Copyright 2018 Autodesk, Inc.  All rights reserved.
//
// Use of this software is subject to the terms of the Autodesk
// license agreement provided at the time of installation or download,
// or which otherwise accompanies this software in either electronic
// or hard copy form.
// ==========================================================================
//+

#include "TessellatedQuadGeomOverride.h"
#include "CrackFreePrimitiveGenerator.h"

#include <maya/MViewport2Renderer.h>
#include <maya/MHWGeometryUtilities.h>
#include <maya/MFragmentManager.h>
#include <maya/MShaderManager.h>
#include <maya/MTextureManager.h>
#include <maya/MUintArray.h>
#include <maya/MSelectionMask.h>
#include <maya/MGlobal.h>

#include <string.h>

namespace
{
    const MString kWireframeItemName("tessellatedQuadWireframe");

    const MString kTessellatedItemName("tessellatedQuadTessellated");
    const MString kTessellatedSelectorItemName("tessellatedQuadTessellatedSelector");

    const MString kTessellatedWireframeItemName("tessellatedQuadTessellatedWireframe");
    const MString kTessellatedWireframeSelectorItemName("tessellatedQuadTessellatedWireframeSelector");

    /*
            3----2 (1,1)
            |   /
            | 0/
            | /  2
            |/  /|
            0  / |
              /1 |
             /   |
    (-1,-1) 0----1

    */
    const unsigned int kNumPoints = 4;
    const unsigned int kNumTris = 2;
    const float kPlanePnts[kNumPoints][3] = {
        {-1.0, 0.0, -1.0},
        {1.0, 0.0, -1.0},
        {1.0, 0.0, 1.0},
        {-1.0, 0.0, 1.0}
    };
    const unsigned int kPlaneTriVertIndexes[kNumTris][3] = {
        {0, 1, 2},
        {2, 3, 0}
    };
    const float kPlaneUVs[kNumPoints][2] = {
        {0.0, 1.0},
        {1.0, 1.0},
        {1.0, 0.0},
        {0.0, 0.0}
    };
    const unsigned int kPlaneWireVertIndexes[kNumPoints][2] = {
        {0, 1},
        {1, 2},
        {2, 3},
        {3, 0}
    };
}

void TessellatedQuadGeomOverride::updateRenderItems(
    const MDagPath &path,
    MHWRender::MRenderItemList& list)
{
    const MHWRender::MRenderer* renderer = MHWRender::MRenderer::theRenderer();
    if (!renderer) return;

    const MHWRender::MShaderManager *shaderMgr = renderer->getShaderManager();
    MHWRender::MTextureManager* textureMgr = renderer->getTextureManager();
    if (!shaderMgr || !textureMgr) return;

    MHWRender::MRenderItem *wireframeItem = nullptr;

    int idx = list.indexOf(kWireframeItemName);
    if (idx >= 0)
    {
        wireframeItem = list.itemAt(idx);
    }
    else
    {
        wireframeItem = MHWRender::MRenderItem::Create(kWireframeItemName,
            MHWRender::MRenderItem::NonMaterialSceneItem,
            MHWRender::MGeometry::kLines,
            1);

        wireframeItem->setDrawMode(MHWRender::MGeometry::kAll);

        list.append(wireframeItem);
    }

    if (wireframeItem)
    {
        MHWRender::MShaderInstance *shader = shaderMgr->getStockShader(
            MHWRender::MShaderManager::MStockShader::k3dThickLineShader);

        if (shader)
        {
            MColor wireColor = MHWRender::MGeometryUtilities::wireframeColor(path);
            const float color[4] = { wireColor.r, wireColor.g, wireColor.b, 1.0f };
            shader->setParameter( "solidColor", color);

            wireframeItem->setShader(shader);
            shaderMgr->releaseShader(shader);
        }

        wireframeItem->depthPriority(
            MHWRender::MGeometryUtilities::displayStatus(path) == MHWRender::kDormant ?
            MHWRender::MRenderItem::sDormantWireDepthPriority :
            MHWRender::MRenderItem::sActiveWireDepthPriority);
    }

    const unsigned int triStride = CrackFreePrimitiveGenerator::computeTriangleSize(
        true /*bAddAdjacentEdges*/, true /*bAddDominantEdges*/, true /*bAddDominantPosition*/);

    // The plugin assumes that the devkit location follows "Setting up your build
    // environment" at Maya Developer Help; otherwise, shaders/textures cannot be
    // located. In this case create a mod (module description file) as below in a
    // suitable modules folder (getenv "MAYA_MODULE_PATH") and restart Maya.
    //
    //   + devkit 1.0 <local devkit path>
    //
    MString devkitLocation;
    if (!MGlobal::executeCommand(MString("getModulePath -moduleName \"devkit\""), devkitLocation))
    {
        devkitLocation = MString(getenv("MAYA_LOCATION")) + MString("/devkit");
    }

    MString shaderLocation = devkitLocation +
        MString(renderer->drawAPI() == MHWRender::kDirectX11 ? 
                "/plug-ins/tessellatedQuad/TessellationExample.fx" :
                "/plug-ins/tessellatedQuad/TessellationExample.ogsfx");

    MString textureLocation = devkitLocation +
        MString("/plug-ins/tessellatedQuad/moonHeightMapSharp.jpg");

    if (list.indexOf(kTessellatedItemName) < 0)
    {
        MHWRender::MRenderItem *shadedItem = MHWRender::MRenderItem::Create(kTessellatedItemName,
            MHWRender::MRenderItem::MaterialSceneItem,
            MHWRender::MGeometry::kPatch,
            triStride);

        shadedItem->setDrawMode(MHWRender::MGeometry::DrawMode(
            MHWRender::MGeometry::kShaded | MHWRender::MGeometry::kTextured));

        // do not allow selection on this render item
        MSelectionMask nullMask;
        shadedItem->setSelectionMask(nullMask);

        shadedItem->setExcludedFromPostEffects(false);
        shadedItem->castsShadows(true);
        shadedItem->receivesShadows(true);

        list.append(shadedItem);

        MHWRender::MShaderInstance* tessellationShader =
            shaderMgr->getEffectsFileShader(shaderLocation, "Main");

        if (tessellationShader)
        {
            MHWRender::MTexture* texture = textureMgr->acquireTexture(textureLocation, "");

            MTextureAssignment assignment;
            assignment.texture = texture;
            tessellationShader->setParameter("gHeightMap", assignment);

            shadedItem->setShader(tessellationShader);

            textureMgr->releaseTexture(texture);
            shaderMgr->releaseShader(tessellationShader);
        }
        else
        {
            MString er = shaderMgr->getLastError();
            MString erSrc = shaderMgr->getLastErrorSource(true, true);
            std::cerr << "Error when loading: " << er << std::endl;
            std::cerr << erSrc << std::endl;
        }
    }

    // set up selection item for Viewport 2.0 selection
    if (list.indexOf(kTessellatedSelectorItemName) < 0)
    {
        MHWRender::MRenderItem* selectionItem = MHWRender::MRenderItem::Create(kTessellatedSelectorItemName,
            MHWRender::MRenderItem::MaterialSceneItem,
            MHWRender::MGeometry::kPatch,
            triStride);

        selectionItem->setDrawMode(MHWRender::MGeometry::DrawMode(
            MHWRender::MGeometry::kShaded |
            MHWRender::MGeometry::kTextured |
            MHWRender::MGeometry::kSelectionOnly));

        list.append(selectionItem);

        MHWRender::MShaderInstance* selectionShader =
            shaderMgr->getEffectsFileShader(shaderLocation, "Main_Selection");

        if (selectionShader)
        {
            MHWRender::MTexture* texture = textureMgr->acquireTexture(textureLocation, "");

            MTextureAssignment assignment;
            assignment.texture = texture;
            selectionShader->setParameter("gHeightMap", assignment);

            selectionItem->setShader(selectionShader);

            textureMgr->releaseTexture(texture);
            shaderMgr->releaseShader(selectionShader);
        }
        else
        {
            MString er = shaderMgr->getLastError();
            MString erSrc = shaderMgr->getLastErrorSource(true, true);
            std::cerr << "Error when loading: " << er << std::endl;
            std::cerr << erSrc << std::endl;
        }
    }

    if (list.indexOf(kTessellatedWireframeItemName) < 0)
    {
        MHWRender::MRenderItem *shadedItem = MHWRender::MRenderItem::Create(
            kTessellatedWireframeItemName,
            MHWRender::MRenderItem::MaterialSceneItem,
            MHWRender::MGeometry::kPatch,
            triStride);

        shadedItem->setDrawMode(MHWRender::MGeometry::kWireframe);

        // do not allow selection on this render item
        MSelectionMask nullMask;
        shadedItem->setSelectionMask(nullMask);

        shadedItem->setExcludedFromPostEffects(false);
        shadedItem->castsShadows(true);
        shadedItem->receivesShadows(true);

        list.append(shadedItem);

        MHWRender::MShaderInstance* tessellationShader =
            shaderMgr->getEffectsFileShader(shaderLocation, "Wireframe");

        if (tessellationShader)
        {
            MHWRender::MTexture* texture = textureMgr->acquireTexture(textureLocation, "");

            MTextureAssignment assignment;
            assignment.texture = texture;
            tessellationShader->setParameter("gHeightMap", assignment);

            shadedItem->setShader(tessellationShader);

            textureMgr->releaseTexture(texture);
            shaderMgr->releaseShader(tessellationShader);
        }
        else
        {
            MString er = shaderMgr->getLastError();
            MString erSrc = shaderMgr->getLastErrorSource(true, true);
            std::cerr << "Error when loading: " << er << std::endl;
            std::cerr << erSrc << std::endl;
        }
    }

    // set up selection item for Viewport 2.0 selection
    if (list.indexOf(kTessellatedWireframeSelectorItemName) < 0)
    {
        MHWRender::MRenderItem* selectionItem = MHWRender::MRenderItem::Create(kTessellatedWireframeSelectorItemName,
            MHWRender::MRenderItem::MaterialSceneItem,
            MHWRender::MGeometry::kPatch,
            triStride);

        selectionItem->setDrawMode(MHWRender::MGeometry::DrawMode(
            MHWRender::MGeometry::kWireframe |
            MHWRender::MGeometry::kSelectionOnly));

        list.append(selectionItem);

        MHWRender::MShaderInstance* selectionShader =
            shaderMgr->getEffectsFileShader(shaderLocation, "Wireframe_Selection");

        if (selectionShader)
        {
            MHWRender::MTexture* texture = textureMgr->acquireTexture(textureLocation, "");

            MTextureAssignment assignment;
            assignment.texture = texture;
            selectionShader->setParameter("gHeightMap", assignment);

            selectionItem->setShader(selectionShader);

            textureMgr->releaseTexture(texture);
            shaderMgr->releaseShader(selectionShader);
        }
        else
        {
            MString er = shaderMgr->getLastError();
            MString erSrc = shaderMgr->getLastErrorSource(true, true);
            std::cerr << "Error when loading: " << er << std::endl;
            std::cerr << erSrc << std::endl;
        }
    }
}

void TessellatedQuadGeomOverride::populateGeometry(
    const MHWRender::MGeometryRequirements &requirements,
    const MHWRender::MRenderItemList &renderItems,
    MHWRender::MGeometry &data)
{
    MHWRender::MVertexBuffer *positionBuffer = NULL;
    MHWRender::MVertexBuffer *uvBuffer = NULL;

    const MHWRender::MVertexBufferDescriptorList &vbDescriptors = requirements.vertexRequirements();
    MHWRender::MVertexBufferDescriptor vbDescriptor;
    for ( int ri = 0; ri < vbDescriptors.length(); ++ri )
    {
        if ( !vbDescriptors.getDescriptor( ri, vbDescriptor ) )
            continue;

        switch ( vbDescriptor.semantic() )
        {
        case MHWRender::MGeometry::kPosition:
            {
                positionBuffer = data.createVertexBuffer(vbDescriptor);
                if (positionBuffer)
                {
                    float *verts = (float *) positionBuffer->acquire(kNumPoints, false);
                    memcpy(verts, kPlanePnts, sizeof(float) * kNumPoints * 3);
                    positionBuffer->commit(verts);
                }
            }
            break;
        case MHWRender::MGeometry::kNormal:
            {
                MHWRender::MVertexBuffer *vb = data.createVertexBuffer(vbDescriptor);
                if (vb)
                {
                    float *normals= (float *) vb->acquire(kNumPoints, true);
                    for ( unsigned int ni=0; ni<kNumPoints; ++ni )
                    {
                        normals[ni*3 + 0] = 0.0f;
                        normals[ni*3 + 1] = 1.0f;
                        normals[ni*3 + 2] = 0.0f;
                    }
                    vb->commit(normals);
                }
            }
            break;
        case MHWRender::MGeometry::kTexture:
            {
                uvBuffer = data.createVertexBuffer(vbDescriptor);
                if (uvBuffer)
                {
                    float *uvs = (float *) uvBuffer->acquire(kNumPoints, false);
                    memcpy(uvs, kPlaneUVs, sizeof(float) * kNumPoints * 2);
                    uvBuffer->commit(uvs);
                }       
            }
            break;
        default:
            // ignore unknown semantics!
            std::cerr << "Unexpected vb descriptor: " << vbDescriptor.semanticName() << std::endl;
            break;
        };
    }

    // For our index buffer, we need to generate connectivity information. The
    // calculation can be expensive so we share the index buffer among render
    // items if possible to avoid repetitive calculation.
    //
    MHWRender::MIndexBuffer *patchIB = nullptr;

    const unsigned int triStride = CrackFreePrimitiveGenerator::computeTriangleSize(
        true /*bAddAdjacentEdges*/, true /*bAddDominantEdges*/, true /*bAddDominantPosition*/);

    for ( int ri = 0; ri < renderItems.length(); ++ri )
    {
        const MHWRender::MRenderItem* item = renderItems.itemAt(ri);
        if ( !item )
            continue;

        MString itemName = item->name();

        if ( itemName == kWireframeItemName )
        {
            MHWRender::MIndexBuffer *ib = data.createIndexBuffer(MHWRender::MGeometry::kUnsignedInt32);
            if (ib)
            {
                unsigned int* indexes = (unsigned int *) ib->acquire(kNumPoints * 2);
                memcpy(indexes, kPlaneWireVertIndexes, sizeof(unsigned int) * kNumPoints * 2);
                ib->commit(indexes);
                item->associateWithIndexBuffer(ib);
            }
        }
        else if (
            itemName == kTessellatedItemName ||
            itemName == kTessellatedSelectorItemName ||
            itemName == kTessellatedWireframeItemName ||
            itemName == kTessellatedWireframeSelectorItemName )
        {
            if (!patchIB)
            {
                patchIB = data.createIndexBuffer(MHWRender::MGeometry::kUnsignedInt32);
                if (patchIB)
                {
                    MUintArray triIndices(kPlaneTriVertIndexes[0], kNumTris * 3);
                    float * positionBufferFloat = (float *)positionBuffer->map();
                    float * uvBufferFloat = NULL;
                    if (uvBuffer) uvBufferFloat = (float *)uvBuffer->map();

                    const unsigned int bufferSize = kNumTris * triStride;

                    unsigned int* indexes = (unsigned int*)patchIB->acquire(bufferSize, true /*writeOnly - we don't need the current buffer values*/);

                    CrackFreePrimitiveGenerator::mutateIndexBuffer(triIndices,
                        positionBufferFloat,
                        uvBufferFloat,
                        true /*add adjacent edges*/,
                        true /*add dominant edges*/,
                        true /*add dominant position*/,
                        patchIB->dataType(),
                        indexes);

                    if (positionBuffer) positionBuffer->unmap();
                    if (uvBuffer) uvBuffer->unmap();

                    patchIB->commit(indexes);
                }
            }

            if (patchIB)
            {
                item->associateWithIndexBuffer(patchIB);
            }
        }
    }
}