llviewercamera.cpp

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#include "llviewerprecompiledheaders.h"
#include "llviewercamera.h"

#include <iomanip> // for setprecision

#include "llquaternion.h"

#include "llagent.h"
#include "llviewercontrol.h"
#include "lldrawable.h"
#include "llface.h"
#include "llgl.h"
#include "llglheaders.h"
#include "llviewerobjectlist.h"
#include "llviewerregion.h"
#include "llviewerwindow.h"
#include "llvovolume.h"
#include "llworld.h"
#include "lltoolmgr.h"
#include "llviewerjoystick.h"

GLfloat gGLZFar;
GLfloat gGLZNear;

//glu pick matrix implementation borrowed from Mesa3D
glh::matrix4f gl_pick_matrix(GLfloat x, GLfloat y, GLfloat width, GLfloat height, GLint* viewport)
{
        GLfloat m[16];
        GLfloat sx, sy;
        GLfloat tx, ty;

        sx = viewport[2] / width;
        sy = viewport[3] / height;
        tx = (viewport[2] + 2.f * (viewport[0] - x)) / width;
        ty = (viewport[3] + 2.f * (viewport[1] - y)) / height;

        #define M(row,col) m[col*4+row]
        M(0,0) = sx; M(0,1) = 0.f; M(0,2) = 0.f; M(0,3) = tx;
        M(1,0) = 0.f; M(1,1) = sy; M(1,2) = 0.f; M(1,3) = ty;
        M(2,0) = 0.f; M(2,1) = 0.f; M(2,2) = 1.f; M(2,3) = 0.f;
        M(3,0) = 0.f; M(3,1) = 0.f; M(3,2) = 0.f; M(3,3) = 1.f;
        #undef M

        return glh::matrix4f(m);
}

glh::matrix4f gl_perspective(GLfloat fovy, GLfloat aspect, GLfloat zNear, GLfloat zFar)
{
        GLfloat f = 1.f/tanf(DEG_TO_RAD*fovy/2.f);

        return glh::matrix4f(f/aspect, 0, 0, 0,
                                                 0, f, 0, 0,
                                                 0, 0, (zFar+zNear)/(zNear-zFar), (2.f*zFar*zNear)/(zNear-zFar),
                                                 0, 0, -1.f, 0);
}

LLViewerCamera::LLViewerCamera() : LLCamera()
{
        calcProjection(getFar());
        mCameraFOVDefault = DEFAULT_FIELD_OF_VIEW;
        mPixelMeterRatio = 0.f;
        mScreenPixelArea = 0;
        mZoomFactor = 1.f;
        mZoomSubregion = 1;
}

void LLViewerCamera::updateCameraLocation(const LLVector3 &center,
                                                                                        const LLVector3 &up_direction,
                                                                                        const LLVector3 &point_of_interest)
{
        // do not update if we are in build mode AND avatar didn't move
        if (LLToolMgr::getInstance()->inBuildMode() 
                && !LLViewerJoystick::getInstance()->getCameraNeedsUpdate())
        {
                return;
        }

        LLVector3 last_position;
        LLVector3 last_axis;
        last_position = getOrigin();
        last_axis = getAtAxis();

        mLastPointOfInterest = point_of_interest;

        // constrain to max distance from avatar
        LLVector3 camera_offset = center - gAgent.getPositionAgent();

        LLViewerRegion * regp = gAgent.getRegion();
        F32 water_height = (NULL != regp) ? regp->getWaterHeight() : 0.f;

        LLVector3 origin = center;
        if (origin.mV[2] > water_height)
        {
                origin.mV[2] = llmax(origin.mV[2], water_height+0.20f);
        }
        else
        {
                origin.mV[2] = llmin(origin.mV[2], water_height-0.20f);
        }

        setOriginAndLookAt(origin, up_direction, point_of_interest);

        F32 dpos = (center - last_position).magVec();
        LLQuaternion rotation;
        rotation.shortestArc(last_axis, getAtAxis());

        F32 x, y, z;
        F32 drot;
        rotation.getAngleAxis(&drot, &x, &y, &z);
        mVelocityStat.addValue(dpos);
        mAngularVelocityStat.addValue(drot);
        // update pixel meter ratio using default fov, not modified one
        mPixelMeterRatio = mViewHeightInPixels / (2.f*tanf(mCameraFOVDefault*0.5));
        // update screen pixel area
        mScreenPixelArea =(S32)((F32)mViewHeightInPixels * ((F32)mViewHeightInPixels * mAspect));
}

// Handy copies of last good GL matrices
F64     gGLModelView[16];
F64     gGLLastModelView[16];
F64 gGLProjection[16];
S32     gGLViewport[4];

const LLMatrix4 &LLViewerCamera::getProjection() const
{
        calcProjection(getFar());
        return mProjectionMatrix;

}

const LLMatrix4 &LLViewerCamera::getModelview() const
{
        LLMatrix4 cfr(OGL_TO_CFR_ROTATION);
        getMatrixToLocal(mModelviewMatrix);
        mModelviewMatrix *= cfr;
        return mModelviewMatrix;
}

void LLViewerCamera::calcProjection(const F32 far_distance) const
{
        F32 fov_y, z_far, z_near, aspect, f;
        fov_y = getView();
        z_far = far_distance;
        z_near = getNear();
        aspect = getAspect();

        f = 1/tan(fov_y*0.5f);

        mProjectionMatrix.setZero();
        mProjectionMatrix.mMatrix[0][0] = f/aspect;
        mProjectionMatrix.mMatrix[1][1] = f;
        mProjectionMatrix.mMatrix[2][2] = (z_far + z_near)/(z_near - z_far);
        mProjectionMatrix.mMatrix[3][2] = (2*z_far*z_near)/(z_near - z_far);
        mProjectionMatrix.mMatrix[2][3] = -1;
}

// Sets up opengl state for 3D drawing.  If for selection, also
// sets up a pick matrix.  x and y are ignored if for_selection is false.
// The picking region is centered on x,y and has the specified width and
// height.

//static
void LLViewerCamera::updateFrustumPlanes(LLCamera& camera, BOOL ortho, BOOL zflip)
{
        GLint* viewport = (GLint*) gGLViewport;
        GLdouble* model = gGLModelView;
        GLdouble* proj = gGLProjection;
        GLdouble objX,objY,objZ;

        LLVector3 frust[8];

        if (zflip)
        {
                gluUnProject(viewport[0],viewport[1]+viewport[3],0,model,proj,viewport,&objX,&objY,&objZ);
                frust[0].setVec((F32)objX,(F32)objY,(F32)objZ);
                gluUnProject(viewport[0]+viewport[2],viewport[1]+viewport[3],0,model,proj,viewport,&objX,&objY,&objZ);
                frust[1].setVec((F32)objX,(F32)objY,(F32)objZ);
                gluUnProject(viewport[0]+viewport[2],viewport[1],0,model,proj,viewport,&objX,&objY,&objZ);
                frust[2].setVec((F32)objX,(F32)objY,(F32)objZ);
                gluUnProject(viewport[0],viewport[1],0,model,proj,viewport,&objX,&objY,&objZ);
                frust[3].setVec((F32)objX,(F32)objY,(F32)objZ);

                gluUnProject(viewport[0],viewport[1]+viewport[3],1,model,proj,viewport,&objX,&objY,&objZ);
                frust[4].setVec((F32)objX,(F32)objY,(F32)objZ);
                gluUnProject(viewport[0]+viewport[2],viewport[1]+viewport[3],1,model,proj,viewport,&objX,&objY,&objZ);
                frust[5].setVec((F32)objX,(F32)objY,(F32)objZ);
                gluUnProject(viewport[0]+viewport[2],viewport[1],1,model,proj,viewport,&objX,&objY,&objZ);
                frust[6].setVec((F32)objX,(F32)objY,(F32)objZ);
                gluUnProject(viewport[0],viewport[1],1,model,proj,viewport,&objX,&objY,&objZ);
                frust[7].setVec((F32)objX,(F32)objY,(F32)objZ);

                for (U32 i = 0; i < 4; i++)
                {
                        frust[i+4] = frust[i+4]-frust[i];
                        frust[i+4].normVec();
                        frust[i+4] = frust[i] + frust[i+4]*camera.getFar();
                }
        }
        else
        {
                gluUnProject(viewport[0],viewport[1],0,model,proj,viewport,&objX,&objY,&objZ);
                frust[0].setVec((F32)objX,(F32)objY,(F32)objZ);
                gluUnProject(viewport[0]+viewport[2],viewport[1],0,model,proj,viewport,&objX,&objY,&objZ);
                frust[1].setVec((F32)objX,(F32)objY,(F32)objZ);
                gluUnProject(viewport[0]+viewport[2],viewport[1]+viewport[3],0,model,proj,viewport,&objX,&objY,&objZ);
                frust[2].setVec((F32)objX,(F32)objY,(F32)objZ);
                gluUnProject(viewport[0],viewport[1]+viewport[3],0,model,proj,viewport,&objX,&objY,&objZ);
                frust[3].setVec((F32)objX,(F32)objY,(F32)objZ);
                
                if (ortho)
                {
                        LLVector3 far_shift = LLVector3(camera.getFar()*2.0f,0,0);
                        for (U32 i = 0; i < 4; i++)
                        {
                                frust[i+4] = frust[i] + far_shift;
                        }
                }
                else
                {
                        for (U32 i = 0; i < 4; i++)
                        {
                                LLVector3 vec = frust[i] - camera.getOrigin();
                                vec.normVec();
                                frust[i+4] = camera.getOrigin() + vec*camera.getFar();
                        }
                }
        }

        camera.calcAgentFrustumPlanes(frust);
}

void LLViewerCamera::setPerspective(BOOL for_selection,
                                                                        S32 x, S32 y_from_bot, S32 width, S32 height,
                                                                        BOOL limit_select_distance,
                                                                        F32 z_near, F32 z_far)
{
        F32 fov_y, aspect;
        fov_y = RAD_TO_DEG * getView();
        BOOL z_default_near, z_default_far = FALSE;
        if (z_far <= 0)
        {
                z_default_far = TRUE;
                z_far = getFar();
        }
        if (z_near <= 0)
        {
                z_default_near = TRUE;
                z_near = getNear();
        }
        aspect = getAspect();

        // Load camera view matrix
        glMatrixMode( GL_PROJECTION );
        glLoadIdentity();

        glh::matrix4f proj_mat;

        if (for_selection)
        {
                // make a tiny little viewport
                // anything drawn into this viewport will be "selected"
                GLint*          viewport = (GLint*) gGLViewport;
                
                proj_mat = gl_pick_matrix(x+width/2.f, y_from_bot+height/2.f, (GLfloat) width, (GLfloat) height, viewport);

                if (limit_select_distance)
                {
                        // ...select distance from control
                        z_far = gSavedSettings.getF32("MaxSelectDistance");
                }
                else
                {
                        z_far = gAgent.mDrawDistance;
                }
        }
        else
        {
                // Only override the far clip if it's not passed in explicitly.
                if (z_default_far)
                {
                        z_far = MAX_FAR_CLIP;
                }
                glViewport(x, y_from_bot, width, height);
                gGLViewport[0] = x;
                gGLViewport[1] = y_from_bot;
                gGLViewport[2] = width;
                gGLViewport[3] = height;
        }
        
        if (mZoomFactor > 1.f)
        {
                float offset = mZoomFactor - 1.f;
                int pos_y = mZoomSubregion / llceil(mZoomFactor);
                int pos_x = mZoomSubregion - (pos_y*llceil(mZoomFactor));
                glh::matrix4f translate;
                translate.set_translate(glh::vec3f(offset - (F32)pos_x * 2.f, offset - (F32)pos_y * 2.f, 0.f));
                glh::matrix4f scale;
                scale.set_scale(glh::vec3f(mZoomFactor, mZoomFactor, 1.f));

                proj_mat = scale*proj_mat;
                proj_mat = translate*proj_mat;
        }

        calcProjection(z_far); // Update the projection matrix cache

        proj_mat *= gl_perspective(fov_y,aspect,z_near,z_far);

        glLoadMatrixf(proj_mat.m);

        for (U32 i = 0; i < 16; i++)
        {
                gGLProjection[i] = proj_mat.m[i];
        }

        gGLZNear = z_near;
        gGLZFar = z_far;

        glMatrixMode( GL_MODELVIEW );

        glh::matrix4f modelview((GLfloat*) OGL_TO_CFR_ROTATION);

        GLfloat                 ogl_matrix[16];

        getOpenGLTransform(ogl_matrix);

        modelview *= glh::matrix4f(ogl_matrix);
        
        glLoadMatrixf(modelview.m);
        
        if (for_selection && (width > 1 || height > 1))
        {
                calculateFrustumPlanesFromWindow((F32)(x - width / 2) / (F32)gViewerWindow->getWindowWidth() - 0.5f,
                                                                (F32)(y_from_bot - height / 2) / (F32)gViewerWindow->getWindowHeight() - 0.5f,
                                                                (F32)(x + width / 2) / (F32)gViewerWindow->getWindowWidth() - 0.5f,
                                                                (F32)(y_from_bot + height / 2) / (F32)gViewerWindow->getWindowHeight() - 0.5f);

        }

        // if not picking and not doing a snapshot, cache various GL matrices
        if (!for_selection && mZoomFactor == 1.f)
        {
                // Save GL matrices for access elsewhere in code, especially project_world_to_screen
                //glGetDoublev(GL_MODELVIEW_MATRIX, gGLModelView);
                for (U32 i = 0; i < 16; i++)
                {
                        gGLModelView[i] = modelview.m[i];
                }
        }

        updateFrustumPlanes(*this);

        if (gSavedSettings.getBOOL("CameraOffset"))
        {
                glMatrixMode(GL_PROJECTION);
                glTranslatef(0,0,-50);
                glRotatef(20.0,1,0,0);
                glMatrixMode(GL_MODELVIEW);
        }
}


// Uses the last GL matrices set in set_perspective to project a point from
// screen coordinates to the agent's region.
void LLViewerCamera::projectScreenToPosAgent(const S32 screen_x, const S32 screen_y, LLVector3* pos_agent) const
{

        GLdouble x, y, z;
        gluUnProject(
                GLdouble(screen_x), GLdouble(screen_y), 0.0,
                gGLModelView, gGLProjection, (GLint*)gGLViewport,
                &x,
                &y,
                &z );
        pos_agent->setVec( (F32)x, (F32)y, (F32)z );
}

// Uses the last GL matrices set in set_perspective to project a point from
// the agent's region space to screen coordinates.  Returns TRUE if point in within
// the current window.
BOOL LLViewerCamera::projectPosAgentToScreen(const LLVector3 &pos_agent, LLCoordGL &out_point, const BOOL clamp) const
{
        BOOL in_front = TRUE;
        GLdouble        x, y, z;                        // object's window coords, GL-style

        LLVector3 dir_to_point = pos_agent - getOrigin();
        dir_to_point /= dir_to_point.magVec();

        if (dir_to_point * getAtAxis() < 0.f)
        {
                if (clamp)
                {
                        return FALSE;
                }
                else
                {
                        in_front = FALSE;
                }
        }

        if (GL_TRUE == gluProject(pos_agent.mV[VX], pos_agent.mV[VY], pos_agent.mV[VZ],
                                                                gGLModelView, gGLProjection, (GLint*)gGLViewport,
                                                                &x, &y, &z))
        {
                // convert screen coordinates to virtual UI coordinates
                x /= gViewerWindow->getDisplayScale().mV[VX];
                y /= gViewerWindow->getDisplayScale().mV[VY];

                // should now have the x,y coords of grab_point in screen space
                const LLRect& window_rect = gViewerWindow->getWindowRect();

                // ...sanity check
                S32 int_x = lltrunc(x);
                S32 int_y = lltrunc(y);

                BOOL valid = TRUE;

                if (clamp)
                {
                        if (int_x < window_rect.mLeft)
                        {
                                out_point.mX = window_rect.mLeft;
                                valid = FALSE;
                        }
                        else if (int_x > window_rect.mRight)
                        {
                                out_point.mX = window_rect.mRight;
                                valid = FALSE;
                        }
                        else
                        {
                                out_point.mX = int_x;
                        }

                        if (int_y < window_rect.mBottom)
                        {
                                out_point.mY = window_rect.mBottom;
                                valid = FALSE;
                        }
                        else if (int_y > window_rect.mTop)
                        {
                                out_point.mY = window_rect.mTop;
                                valid = FALSE;
                        }
                        else
                        {
                                out_point.mY = int_y;
                        }
                        return valid;
                }
                else
                {
                        out_point.mX = int_x;
                        out_point.mY = int_y;

                        if (int_x < window_rect.mLeft)
                        {
                                valid = FALSE;
                        }
                        else if (int_x > window_rect.mRight)
                        {
                                valid = FALSE;
                        }
                        if (int_y < window_rect.mBottom)
                        {
                                valid = FALSE;
                        }
                        else if (int_y > window_rect.mTop)
                        {
                                valid = FALSE;
                        }

                        return in_front && valid;
                }
        }
        else
        {
                return FALSE;
        }
}

// Uses the last GL matrices set in set_perspective to project a point from
// the agent's region space to the nearest edge in screen coordinates.
// Returns TRUE if projection succeeds.
BOOL LLViewerCamera::projectPosAgentToScreenEdge(const LLVector3 &pos_agent,
                                                                                                LLCoordGL &out_point) const
{
        LLVector3 dir_to_point = pos_agent - getOrigin();
        dir_to_point /= dir_to_point.magVec();

        BOOL in_front = TRUE;
        if (dir_to_point * getAtAxis() < 0.f)
        {
                in_front = FALSE;
        }

        GLdouble        x, y, z;                        // object's window coords, GL-style
        if (GL_TRUE == gluProject(pos_agent.mV[VX], pos_agent.mV[VY],
                                                          pos_agent.mV[VZ], gGLModelView,
                                                          gGLProjection, (GLint*)gGLViewport,
                                                          &x, &y, &z))
        {
                x /= gViewerWindow->getDisplayScale().mV[VX];
                y /= gViewerWindow->getDisplayScale().mV[VY];
                // should now have the x,y coords of grab_point in screen space
                const LLRect& window_rect = gViewerWindow->getVirtualWindowRect();

                // ...sanity check
                S32 int_x = lltrunc(x);
                S32 int_y = lltrunc(y);

                // find the center
                GLdouble center_x = (GLdouble)(0.5f * (window_rect.mLeft + window_rect.mRight));
                GLdouble center_y = (GLdouble)(0.5f * (window_rect.mBottom + window_rect.mTop));

                if (x == center_x  &&  y == center_y)
                {
                        // can't project to edge from exact center
                        return FALSE;
                }

                // find the line from center to local
                GLdouble line_x = x - center_x;
                GLdouble line_y = y - center_y;

                int_x = lltrunc(center_x);
                int_y = lltrunc(center_y);


                if (0.f == line_x)
                {
                        // the slope of the line is undefined
                        if (line_y > 0.f)
                        {
                                int_y = window_rect.mTop;
                        }
                        else
                        {
                                int_y = window_rect.mBottom;
                        }
                }
                else if (0 == window_rect.getWidth())
                {
                        // the diagonal slope of the view is undefined
                        if (y < window_rect.mBottom)
                        {
                                int_y = window_rect.mBottom;
                        }
                        else if ( y > window_rect.mTop)
                        {
                                int_y = window_rect.mTop;
                        }
                }
                else
                {
                        F32 line_slope = (F32)(line_y / line_x);
                        F32 rect_slope = ((F32)window_rect.getHeight()) / ((F32)window_rect.getWidth());

                        if (fabs(line_slope) > rect_slope)
                        {
                                if (line_y < 0.f)
                                {
                                        // bottom
                                        int_y = window_rect.mBottom;
                                }
                                else
                                {
                                        // top
                                        int_y = window_rect.mTop;
                                }
                                int_x = lltrunc(((GLdouble)int_y - center_y) / line_slope + center_x);
                        }
                        else if (fabs(line_slope) < rect_slope)
                        {
                                if (line_x < 0.f)
                                {
                                        // left
                                        int_x = window_rect.mLeft;
                                }
                                else
                                {
                                        // right
                                        int_x = window_rect.mRight;
                                }
                                int_y = lltrunc(((GLdouble)int_x - center_x) * line_slope + center_y);
                        }
                        else
                        {
                                // exactly parallel ==> push to the corners
                                if (line_x > 0.f)
                                {
                                        int_x = window_rect.mRight;
                                }
                                else
                                {
                                        int_x = window_rect.mLeft;
                                }
                                if (line_y > 0.0f)
                                {
                                        int_y = window_rect.mTop;
                                }
                                else
                                {
                                        int_y = window_rect.mBottom;
                                }
                        }
                }
                if (!in_front)
                {
                        int_x = window_rect.mLeft + window_rect.mRight - int_x;
                        int_y = window_rect.mBottom + window_rect.mTop - int_y;
                }
                out_point.mX = int_x;
                out_point.mY = int_y;
                return TRUE;
        }
        return FALSE;
}


void LLViewerCamera::getPixelVectors(const LLVector3 &pos_agent, LLVector3 &up, LLVector3 &right)
{
        LLVector3 to_vec = pos_agent - getOrigin();

        F32 at_dist = to_vec * getAtAxis();

        F32 height_meters = at_dist* (F32)tan(getView()/2.f);
        F32 height_pixels = getViewHeightInPixels()/2.f;

        F32 pixel_aspect = gViewerWindow->getWindow()->getPixelAspectRatio();

        F32 meters_per_pixel = height_meters / height_pixels;
        up = getUpAxis() * meters_per_pixel * gViewerWindow->getDisplayScale().mV[VY];
        right = -1.f * pixel_aspect * meters_per_pixel * getLeftAxis() * gViewerWindow->getDisplayScale().mV[VX];
}

LLVector3 LLViewerCamera::roundToPixel(const LLVector3 &pos_agent)
{
        F32 dist = (pos_agent - getOrigin()).magVec();
        // Convert to screen space and back, preserving the depth.
        LLCoordGL screen_point;
        if (!projectPosAgentToScreen(pos_agent, screen_point, FALSE))
        {
                // Off the screen, just return the original position.
                return pos_agent;
        }

        LLVector3 ray_dir;

        projectScreenToPosAgent(screen_point.mX, screen_point.mY, &ray_dir);
        ray_dir -= getOrigin();
        ray_dir.normVec();

        LLVector3 pos_agent_rounded = getOrigin() + ray_dir*dist;

        /*
        LLVector3 pixel_x, pixel_y;
        getPixelVectors(pos_agent_rounded, pixel_y, pixel_x);
        pos_agent_rounded += 0.5f*pixel_x, 0.5f*pixel_y;
        */
        return pos_agent_rounded;
}

BOOL LLViewerCamera::cameraUnderWater() const
{
        return getOrigin().mV[VZ] < gAgent.getRegion()->getWaterHeight();
}

BOOL LLViewerCamera::areVertsVisible(LLViewerObject* volumep, BOOL all_verts)
{
        S32 i, num_faces;
        LLDrawable* drawablep = volumep->mDrawable;

        if (!drawablep)
        {
                return FALSE;
        }

        LLVolume* volume = volumep->getVolume();
        if (!volume)
        {
                return FALSE;
        }

        LLVOVolume* vo_volume = (LLVOVolume*) volumep;

        vo_volume->updateRelativeXform();
        LLMatrix4 mat = vo_volume->getRelativeXform();
        
        LLMatrix4 render_mat(vo_volume->getRenderRotation(), LLVector4(vo_volume->getRenderPosition()));

        num_faces = volume->getNumVolumeFaces();
        for (i = 0; i < num_faces; i++)
        {
                const LLVolumeFace& face = volume->getVolumeFace(i);
                                
                for (U32 v = 0; v < face.mVertices.size(); v++)
                {
                        LLVector4 vec = LLVector4(face.mVertices[v].mPosition) * mat;

                        if (drawablep->isActive())
                        {
                                vec = vec * render_mat; 
                        }

                        BOOL in_frustum = pointInFrustum(LLVector3(vec)) > 0;

                        if ( !in_frustum && all_verts ||
                                 in_frustum && !all_verts)
                        {
                                return !all_verts;
                        }
                }
        }
        return all_verts;
}

---