SharedOpenGL/crserverlib/server_viewport.c

	server_viewport.c revision f53ba2efceac1847585b2052ee98569305e9802d
/* Copyright (c) 2001, Stanford University
 * All rights reserved
 *
 * See the file LICENSE.txt for information on redistributing this software.
 */

#include "server_dispatch.h"
#include "server.h"
#include "cr_error.h"
#include "state/cr_statetypes.h"


static const CRmatrix identity_matrix = {
    1.0, 0.0, 0.0, 0.0,
    0.0, 1.0, 0.0, 0.0,
    0.0, 0.0, 1.0, 0.0,
    0.0, 0.0, 0.0, 1.0
};


/*
 * Clip the rectangle q against the given image window.
 */
static void
crServerViewportClipToWindow( const CRrecti *imagewindow,   CRrecti *q)
{
    if (q->x1 < imagewindow->x1) q->x1 = imagewindow->x1;
    if (q->x1 > imagewindow->x2) q->x1 = imagewindow->x2;

    if (q->x2 > imagewindow->x2) q->x2 = imagewindow->x2;
    if (q->x2 < imagewindow->x1) q->x2 = imagewindow->x1;

    if (q->y1 < imagewindow->y1) q->y1 = imagewindow->y1;
    if (q->y1 > imagewindow->y2) q->y1 = imagewindow->y2;

    if (q->y2 > imagewindow->y2) q->y2 = imagewindow->y2;
    if (q->y2 < imagewindow->y1) q->y2 = imagewindow->y1;
}


/*
 * Translate the rectangle q from the image window space to the outputwindow
 * space.
 */
static void
crServerConvertToOutput( const CRrecti *imagewindow,
                                                 const CRrecti *outputwindow,
                                                 CRrecti *q )
{
    q->x1 = q->x1 - imagewindow->x1 + outputwindow->x1;
    q->x2 = q->x2 - imagewindow->x2 + outputwindow->x2;
    q->y1 = q->y1 - imagewindow->y1 + outputwindow->y1;
    q->y2 = q->y2 - imagewindow->y2 + outputwindow->y2;
}


/*
 * Compute clipped image window, scissor, viewport and base projection
 * info for each tile in the mural.
 * Need to call this when either the viewport or mural is changed.
 */
void
crServerComputeViewportBounds(const CRViewportState *v, CRMuralInfo *mural)
{
#if 0
    static GLuint serialNo = 1;
    int i;

    for (i = 0; i < mural->numExtents; i++) {
        CRExtent *extent = &mural->extents[i];
        CRrecti q;

        /* If the scissor is disabled set it to the whole output.
        ** We might as well use the actual scissorTest rather than
        ** scissorValid - it never gets reset anyway.
        */
        if (!v->scissorTest)
        {
            extent->scissorBox = extent->outputwindow;
        }
        else
        {
            q.x1 = v->scissorX;
            q.x2 = v->scissorX + v->scissorW;
            q.y1 = v->scissorY;
            q.y2 = v->scissorY + v->scissorH;

            crServerViewportClipToWindow(&(extent->imagewindow), &q);
            crServerConvertToOutput(&(extent->imagewindow),
                                                            &(extent->outputwindow), &q);
            extent->scissorBox = q;
        }

        /* if the viewport is not valid,
        ** set it to the entire output.
        */
        if (!v->viewportValid)
        {
            extent->clippedImagewindow = extent->imagewindow;
            extent->viewport = extent->outputwindow;
        }
        else
        {
            q.x1 = v->viewportX;
            q.x2 = v->viewportX + v->viewportW;
            q.y1 = v->viewportY;
            q.y2 = v->viewportY + v->viewportH;

            /* This is where the viewport gets clamped to the max size. */
            crServerViewportClipToWindow(&(extent->imagewindow), &q);

            extent->clippedImagewindow = q;

            crServerConvertToOutput(&(extent->imagewindow),
                                                            &(extent->outputwindow), &q);

            extent->viewport = q;
        }

        /*
        ** Now, compute the base projection.
        */
        if (extent->clippedImagewindow.x1 == extent->clippedImagewindow.x2 ||
                extent->clippedImagewindow.y1 == extent->clippedImagewindow.y2) {
            /* zero-area extent, use identity matrix (doesn't really matter) */
            extent->baseProjection = identity_matrix;
        }
        else
        {
            const int vpx = v->viewportX;
            const int vpy = v->viewportY;
            const int vpw = v->viewportW;
            const int vph = v->viewportH;
            GLfloat xscale, yscale;
            GLfloat xtrans, ytrans;
            CRrectf p;

            /*
             * We need to take account of the current viewport parameters,
             * and they are passed to this function as x, y, w, h.
             * In the default case (from main.c) we pass the the
             * full muralsize of 0, 0, width, height
             */
            p.x1 = (GLfloat) (extent->clippedImagewindow.x1 - vpx) / vpw;
            p.y1 = (GLfloat) (extent->clippedImagewindow.y1 - vpy) / vph;
            p.x2 = (GLfloat) (extent->clippedImagewindow.x2 - vpx) / vpw;
            p.y2 = (GLfloat) (extent->clippedImagewindow.y2 - vpy) / vph;

            /* XXX not sure this clamping is really need anymore
             */
            if (p.x1 < 0.0) {
                p.x1 = 0.0;
                if (p.x2 > 1.0) p.x2 = 1.0;
            }

            if (p.y1 < 0.0) {
                p.y1 = 0.0;
                if (p.y2 > 1.0) p.y2 = 1.0;
            }

            /* Rescale [0,1] -> [-1,1] */
            p.x1 = p.x1 * 2.0f - 1.0f;
            p.x2 = p.x2 * 2.0f - 1.0f;
            p.y1 = p.y1 * 2.0f - 1.0f;
            p.y2 = p.y2 * 2.0f - 1.0f;

            xscale = 2.0f / (p.x2 - p.x1);
            yscale = 2.0f / (p.y2 - p.y1);
            xtrans = -(p.x2 + p.x1) / 2.0f;
            ytrans = -(p.y2 + p.y1) / 2.0f;

            CRASSERT(xscale == xscale); /* NaN test */
            CRASSERT(yscale == yscale);

            extent->baseProjection = identity_matrix;
            extent->baseProjection.m00 = xscale;
            extent->baseProjection.m11 = yscale;
            extent->baseProjection.m30 = xtrans * xscale;
            extent->baseProjection.m31 = ytrans * yscale;
        }

        extent->serialNo = serialNo++;
    }
    mural->viewportValidated = GL_TRUE;
#endif
}


/*
 * Issue the glScissor, glViewport and projection matrix needed for
 * rendering the tile specified by extNum.  We computed the scissor,
 * viewport and projection parameters above in crServerComputeViewportBounds.
 */
void
crServerSetOutputBounds( const CRMuralInfo *mural, int extNum )
{
#if 0
    const CRExtent *extent = mural->extents + extNum;
    CRASSERT(mural->viewportValidated);

    /*
     * Serial Number info:
     * Everytime we compute new scissor, viewport, projection matrix info for
     * a tile, we give that tile a new serial number.
     * When we're about to render into a tile, we only update the scissor,
     * viewport and projection matrix if the tile's serial number doesn't match
     * the current serial number.  This avoids a _LOT_ of redundant calls to
     * those three functions.
     */
    if (extent->serialNo != cr_server.currentSerialNo) {
        cr_server.head_spu->dispatch_table.Scissor(extent->scissorBox.x1,
                                                                 extent->scissorBox.y1,
                                                                 extent->scissorBox.x2 - extent->scissorBox.x1,
                                                                 extent->scissorBox.y2 - extent->scissorBox.y1);

        cr_server.head_spu->dispatch_table.Viewport(extent->viewport.x1,
                                                                 extent->viewport.y1,
                                                                 extent->viewport.x2 - extent->viewport.x1,
                                                                 extent->viewport.y2 - extent->viewport.y1);

        crServerApplyBaseProjection(&(extent->baseProjection));
        cr_server.currentSerialNo = extent->serialNo;
    }
#endif
}


/*
 * Pre-multiply the current projection matrix with the current client's
 * base projection.  I.e.  P' = b * P.  Note that OpenGL's glMultMatrix
 * POST-multiplies.
 */
void
crServerApplyBaseProjection(const CRmatrix *baseProj)
{
    const CRmatrix *projMatrix;
    if (cr_server.projectionOverride) {
        int eye = crServerGetCurrentEye();
        projMatrix = &cr_server.projectionMatrix[eye];
    }
    else
        projMatrix = cr_server.curClient->currentCtxInfo->pContext->transform.projectionStack.top;

    cr_server.head_spu->dispatch_table.PushAttrib( GL_TRANSFORM_BIT );
    cr_server.head_spu->dispatch_table.MatrixMode( GL_PROJECTION );
    cr_server.head_spu->dispatch_table.LoadMatrixf( (const GLfloat *) baseProj );
    cr_server.head_spu->dispatch_table.MultMatrixf( cr_server.alignment_matrix );
    cr_server.head_spu->dispatch_table.MultMatrixf( (const GLfloat *) projMatrix );
    cr_server.head_spu->dispatch_table.PopAttrib();
}


void
crServerApplyViewMatrix(const CRmatrix *view)
{
    const CRmatrix *modelview = cr_server.curClient->currentCtxInfo->pContext->transform.modelViewStack.top;

    cr_server.head_spu->dispatch_table.PushAttrib( GL_TRANSFORM_BIT );
    cr_server.head_spu->dispatch_table.MatrixMode( GL_MODELVIEW );
    cr_server.head_spu->dispatch_table.LoadMatrixf( (const GLfloat *) view );
    cr_server.head_spu->dispatch_table.MultMatrixf( (const GLfloat *) modelview );
    cr_server.head_spu->dispatch_table.PopAttrib();
}


/*
 * Called via unpacker module.
 * Note: when there's a tilesort SPU upstream, the viewport dimensions
 * will typically match the mural size.  That is, the viewport dimensions
 * probably won't be the same values that the application issues.
 */
void SERVER_DISPATCH_APIENTRY crServerDispatchViewport( GLint x, GLint y, GLsizei width, GLsizei height )
{
    CRMuralInfo *mural = cr_server.curClient->currentMural;
    CRContext *ctx = crStateGetCurrent();

    if (ctx->viewport.viewportX != x ||
            ctx->viewport.viewportY != y ||
            ctx->viewport.viewportW != width ||
            ctx->viewport.viewportH != height) {
         /* Note -- If there are tiles, this will be overridden in the
            * process of decoding the BoundsInfo packet, so no worries. */
         crStateViewport( x, y, width, height );
    }

    /* always dispatch to be safe */
    cr_server.head_spu->dispatch_table.Viewport( x, y, width, height );
}