C++ MDrawContext::getLightInformation方法代码示例

// #### bindProgram
//
//      Do all the work to build and install shader including
//      set up buffer blocks for uniform variables, set up
//      default lighting parameters, pass material uniforms
//      and bind texture buffers used by texture maps and by
//      OpenSubdiv's built-in shading code.
//
GLuint
OpenSubdivShader::bindProgram(const MHWRender::MDrawContext &     mDrawContext,
                                    OpenSubdiv::OsdGLDrawContext *osdDrawContext,
                              const OpenSubdiv::OsdDrawContext::PatchArray &   patch)
{

    CHECK_GL_ERROR("bindProgram begin\n");

    // Primitives are triangles for Loop subdivision, quads otherwise
    Effect effect = kFill;
    EffectDesc effectDesc( patch.GetDescriptor(), effect );

    // Build shader
    EffectDrawRegistry::ConfigType *
        config = g_effectRegistry.GetDrawConfig(effectDesc);

    // Install shader
    GLuint program = config->program;
    glUseProgram(program);

    // Update and bind transform state
    struct Transform {
        float ModelViewMatrix[16];
        float ProjectionMatrix[16];
        float ModelViewProjectionMatrix[16];
    } transformData;
    setMatrix(mDrawContext.getMatrix(MHWRender::MDrawContext::kWorldViewMtx),
              transformData.ModelViewMatrix);
    setMatrix(mDrawContext.getMatrix(MHWRender::MDrawContext::kProjectionMtx),
              transformData.ProjectionMatrix);
    setMatrix(mDrawContext.getMatrix(MHWRender::MDrawContext::kWorldViewProjMtx),
              transformData.ModelViewProjectionMatrix);

    if (!g_transformUB) {
        glGenBuffers(1, &g_transformUB);
        glBindBuffer(GL_UNIFORM_BUFFER, g_transformUB);
        glBufferData(GL_UNIFORM_BUFFER,
                sizeof(transformData), NULL, GL_STATIC_DRAW);
    };
    glBindBuffer(GL_UNIFORM_BUFFER, g_transformUB);
    glBufferSubData(GL_UNIFORM_BUFFER,
                0, sizeof(transformData), &transformData);
    glBindBuffer(GL_UNIFORM_BUFFER, 0);

    glBindBufferBase(GL_UNIFORM_BUFFER, g_transformBinding, g_transformUB);

    // Update and bind tessellation state
    struct Tessellation {
        float TessLevel;
    } tessellationData;

    tessellationData.TessLevel = static_cast<float>(1 << _tessFactor);

    if (!g_tessellationUB) {
        glGenBuffers(1, &g_tessellationUB);
        glBindBuffer(GL_UNIFORM_BUFFER, g_tessellationUB);
        glBufferData(GL_UNIFORM_BUFFER,
                sizeof(tessellationData), NULL, GL_STATIC_DRAW);
    };
    glBindBuffer(GL_UNIFORM_BUFFER, g_tessellationUB);
    glBufferSubData(GL_UNIFORM_BUFFER,
                0, sizeof(tessellationData), &tessellationData);
    glBindBuffer(GL_UNIFORM_BUFFER, 0);

    glBindBufferBase(GL_UNIFORM_BUFFER,
                     g_tessellationBinding,
                     g_tessellationUB);


    // Update and bind lighting state
    int numLights = mDrawContext.numberOfActiveLights();
    struct Lighting {
        struct Light {
            float position[4];
            float diffuse[4];
            float ambient[4];
            float specular[4];
        } lightSource[2];
    } lightingData;
    memset(&lightingData, 0, sizeof(lightingData));

    for (int i = 0; i < numLights && i < 2; ++i) {
        MFloatPointArray positions;
        MFloatVector direction;
        float intensity;
        MColor color;
        bool hasDirection, hasPosition;
        mDrawContext.getLightInformation(i, positions, direction, intensity,
                                    color, hasDirection, hasPosition);

        MMatrix modelView = mDrawContext.getMatrix(MHWRender::MDrawContext::kWorldViewMtx);
        direction = MVector(direction) * modelView;
//.........这里部分代码省略.........

GLuint
OpenSubdivPtexShader::bindProgram(const MHWRender::MDrawContext &     mDrawContext,
                                  OpenSubdiv::OsdGLDrawContext *osdDrawContext,
                                  const OpenSubdiv::OsdPatchArray &   patch)
{

    CHECK_GL_ERROR("bindProgram begin\n");

    // Build shader
    Effect effect;
    effect.color = _enableColor;
    effect.occlusion = _enableOcclusion;
    effect.displacement = _enableDisplacement;
    effect.normal = _enableNormal;
    EffectDesc effectDesc( patch.desc, effect );
    EffectDrawRegistry::ConfigType *
    config = effectRegistry.GetDrawConfig(effectDesc);

    // Install shader
    GLuint program = config->program;
    glUseProgram(program);

    // Update and bind transform state
    struct Transform {
        float ModelViewMatrix[16];
        float ProjectionMatrix[16];
        float ModelViewProjectionMatrix[16];
    } transformData;
    setMatrix(mDrawContext.getMatrix(MHWRender::MDrawContext::kWorldViewMtx),
              transformData.ModelViewMatrix);
    setMatrix(mDrawContext.getMatrix(MHWRender::MDrawContext::kProjectionMtx),
              transformData.ProjectionMatrix);
    setMatrix(mDrawContext.getMatrix(MHWRender::MDrawContext::kWorldViewProjMtx),
              transformData.ModelViewProjectionMatrix);

    if (!g_transformUB) {
        glGenBuffers(1, &g_transformUB);
        glBindBuffer(GL_UNIFORM_BUFFER, g_transformUB);
        glBufferData(GL_UNIFORM_BUFFER,
                     sizeof(transformData), NULL, GL_STATIC_DRAW);
    };
    glBindBuffer(GL_UNIFORM_BUFFER, g_transformUB);
    glBufferSubData(GL_UNIFORM_BUFFER,
                    0, sizeof(transformData), &transformData);
    glBindBuffer(GL_UNIFORM_BUFFER, 0);

    glBindBufferBase(GL_UNIFORM_BUFFER, g_transformBinding, g_transformUB);

    // Update and bind tessellation state
    struct Tessellation {
        float TessLevel;
        int GregoryQuadOffsetBase;
        int PrimitiveIdBase;
    } tessellationData;

    tessellationData.TessLevel = static_cast<float>(1 << _tessFactor);
    tessellationData.GregoryQuadOffsetBase = patch.GetQuadOffsetBase;
    tessellationData.PrimitiveIdBase = patch.GetPatchIndex();;

    if (!g_tessellationUB) {
        glGenBuffers(1, &g_tessellationUB);
        glBindBuffer(GL_UNIFORM_BUFFER, g_tessellationUB);
        glBufferData(GL_UNIFORM_BUFFER,
                     sizeof(tessellationData), NULL, GL_STATIC_DRAW);
    };
    glBindBuffer(GL_UNIFORM_BUFFER, g_tessellationUB);
    glBufferSubData(GL_UNIFORM_BUFFER,
                    0, sizeof(tessellationData), &tessellationData);
    glBindBuffer(GL_UNIFORM_BUFFER, 0);

    glBindBufferBase(GL_UNIFORM_BUFFER,
                     g_tessellationBinding,
                     g_tessellationUB);


#ifdef USE_NON_IMAGE_BASED_LIGHTING
    // Update and bind lighting state
    int numLights = mDrawContext.numberOfActiveLights();
    struct Lighting {
        struct Light {
            float position[4];
            float diffuse[4];
            float ambient[4];
            float specular[4];
        } lightSource[2];
    } lightingData;
    memset(&lightingData, 0, sizeof(lightingData));

    for (int i = 0; i < numLights && i < 1; ++i) {
        MFloatPointArray positions;
        MFloatVector direction;
        float intensity;
        MColor color;
        bool hasDirection, hasPosition;
        mDrawContext.getLightInformation(i, positions, direction, intensity,
                                         color, hasDirection, hasPosition);

        Lighting::Light &light = lightingData.lightSource[i];
        if (hasDirection) {
            light.position[0] = -direction[0];
//.........这里部分代码省略.........

PXR_NAMESPACE_OPEN_SCOPE


/* static */
bool
px_vp20Utils::setupLightingGL(const MHWRender::MDrawContext& context)
{
    MStatus status;
    
    // Take into account only the 8 lights supported by the basic
    // OpenGL profile.
    const unsigned int nbLights =
        std::min(context.numberOfActiveLights(&status), 8u);
    if (status != MStatus::kSuccess) return false;

    if (nbLights > 0) {
        // Lights are specified in world space and needs to be
        // converted to view space.
        glMatrixMode(GL_MODELVIEW);
        glPushMatrix();
        const MMatrix worldToView =
            context.getMatrix(MHWRender::MDrawContext::kViewMtx, &status);
        if (status != MStatus::kSuccess) return false;
        glLoadMatrixd(worldToView.matrix[0]);

        glEnable(GL_LIGHTING);
        glColorMaterial(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE);
        glEnable(GL_COLOR_MATERIAL) ;
        glEnable(GL_NORMALIZE) ;

        
        {
            const GLfloat ambient[4]  = { 0.0f, 0.0f, 0.0f, 1.0f };
            const GLfloat specular[4] = { 0.0f, 0.0f, 0.0f, 1.0f };

            glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT,  ambient);
            glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, specular);

            glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambient);

            glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, 1);
        }

        for (unsigned int i=0; i<nbLights; ++i) {
            MFloatVector direction;
            float intensity;
            MColor color;
            bool hasDirection;
            bool hasPosition;
#if MAYA_API_VERSION >= 201300
            // Starting with Maya 2013, getLightInformation() uses MFloatPointArray for positions
            MFloatPointArray positions;
            status = context.getLightInformation(
                i, positions, direction, intensity, color,
                hasDirection, hasPosition);
            const MFloatPoint &position = positions[0];
#else 
            // Maya 2012, getLightInformation() uses MFloatPoint for position
            MFloatPoint position;
            status = context.getLightInformation(
                i, position, direction, intensity, color,
                hasDirection, hasPosition);
#endif
            if (status != MStatus::kSuccess) return false;

            if (hasDirection) {
                if (hasPosition) {
                    // Assumes a Maya Spot Light!
                    const GLfloat ambient[4] = { 0.0f, 0.0f, 0.0f, 1.0f };
                    const GLfloat diffuse[4] = { intensity * color[0],
                                              intensity * color[1],
                                              intensity * color[2],
                                              1.0f };
                    const GLfloat pos[4] = { position[0],
                                              position[1],
                                              position[2],
                                              1.0f };
                    const GLfloat dir[3] = { direction[0],
                                              direction[1],
                                              direction[2]};
                        
                            
                    glLightfv(GL_LIGHT0+i, GL_AMBIENT,  ambient);
                    glLightfv(GL_LIGHT0+i, GL_DIFFUSE,  diffuse);
                    glLightfv(GL_LIGHT0+i, GL_POSITION, pos);
                    glLightfv(GL_LIGHT0+i, GL_SPOT_DIRECTION, dir);

                    // Maya's default value's for spot lights.
                    glLightf(GL_LIGHT0+i,  GL_SPOT_EXPONENT, 0.0);
                    glLightf(GL_LIGHT0+i,  GL_SPOT_CUTOFF,  20.0);
                }
                else {
                    // Assumes a Maya Directional Light!
                    const GLfloat ambient[4] = { 0.0f, 0.0f, 0.0f, 1.0f };
                    const GLfloat diffuse[4] = { intensity * color[0],
                                                  intensity * color[1],
                                                  intensity * color[2],
                                                  1.0f };
                    const GLfloat pos[4] = { -direction[0],
                                              -direction[1],
//.........这里部分代码省略.........