source: vbox/trunk/src/VBox/GuestHost/OpenGL/state_tracker/state_viewport.c@ 36300

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

#include <stdio.h>
#include "state.h"
#include "state/cr_statetypes.h"
#include "state_internals.h"

void crStateViewportInit(CRContext *ctx)
{
        CRViewportState *v = &ctx->viewport;
        CRStateBits *sb = GetCurrentBits();
        CRViewportBits *vb = &(sb->viewport);
        CRTransformBits *tb = &(sb->transform);

        v->scissorTest = GL_FALSE;
        RESET(vb->enable, ctx->bitid);
        
        v->viewportValid = GL_FALSE;
        v->viewportX = 0;
        v->viewportY = 0;
        /* These are defaults, the tilesort spu overrides when
         * the context has been created */
        v->viewportW = 640;
        v->viewportH = 480;
        RESET(vb->v_dims, ctx->bitid);

        v->scissorValid = GL_FALSE;
        v->scissorX = 0;
        v->scissorY = 0;
        /* These are defaults, the tilesort spu overrides when
         * the context has been created */
        v->scissorW = 640;
        v->scissorH = 480;
        RESET(vb->s_dims, ctx->bitid);

        v->farClip = 1.0;
        v->nearClip = 0.0;
        RESET(vb->depth, ctx->bitid);

        RESET(vb->dirty, ctx->bitid);

        /* XXX why are these here? */
        RESET(tb->base, ctx->bitid);
        RESET(tb->dirty, ctx->bitid);
}

void crStateViewportApply(CRViewportState *v, GLvectorf *p) 
{
        p->x = (p->x+1.0f)*(v->viewportW / 2.0f) + v->viewportX;
        p->y = (p->y+1.0f)*(v->viewportH / 2.0f) + v->viewportY;
        p->z = (GLfloat) ((p->z+1.0f)*((v->farClip - v->nearClip) / 2.0f) + v->nearClip);
}

void STATE_APIENTRY crStateViewport(GLint x, GLint y, GLsizei width, 
                        GLsizei height) 
{
        CRContext *g = GetCurrentContext();
        CRViewportState *v = &(g->viewport);
        CRStateBits *sb = GetCurrentBits();
        CRViewportBits *vb = &(sb->viewport);
        CRTransformBits *tb = &(sb->transform);
        
        if (g->current.inBeginEnd)
        {
                crStateError( __LINE__, __FILE__, GL_INVALID_OPERATION,
                                                                        "calling glViewport() between glBegin/glEnd" );
                return;
        }

        FLUSH();
        
        if (width < 0 || height < 0)
        {
                crStateError( __LINE__, __FILE__, GL_INVALID_VALUE,
                                                                        "glViewport(bad width or height)" );
                return;
        }

        if (x > g->limits.maxViewportDims[0]) x = g->limits.maxViewportDims[0];
        if (x < -g->limits.maxViewportDims[0]) x = -g->limits.maxViewportDims[0]; 
        if (y > g->limits.maxViewportDims[1])   y = g->limits.maxViewportDims[1]; 
        if (y < -g->limits.maxViewportDims[1])  y = -g->limits.maxViewportDims[1]; 
        if (width > g->limits.maxViewportDims[0])  width = g->limits.maxViewportDims[0]; 
        if (height > g->limits.maxViewportDims[1])  height = g->limits.maxViewportDims[1];

        v->viewportX = (GLint) (x);
        v->viewportY = (GLint) (y);
        v->viewportW = (GLint) (width);
        v->viewportH = (GLint) (height);

        v->viewportValid = GL_TRUE;

        DIRTY(vb->v_dims, g->neg_bitid);
        DIRTY(vb->dirty, g->neg_bitid);
        /* XXX why are these here? */
        DIRTY(tb->base, g->neg_bitid);
        DIRTY(tb->dirty, g->neg_bitid);
}

void STATE_APIENTRY crStateDepthRange(GLclampd znear, GLclampd zfar) 
{
        CRContext *g = GetCurrentContext();
        CRViewportState *v = &(g->viewport);
        CRStateBits *sb = GetCurrentBits();
        CRViewportBits *vb = &(sb->viewport);
        CRTransformBits *tb = &(sb->transform);

        if (g->current.inBeginEnd)
        {       
                crStateError(__LINE__, __FILE__, GL_INVALID_OPERATION, "glDepthRange called in Begin/End");
                return;
        }

        FLUSH();

        v->nearClip = znear;
        v->farClip = zfar;
        if (v->nearClip < 0.0) v->nearClip = 0.0;
        if (v->nearClip > 1.0) v->nearClip = 1.0;
        if (v->farClip < 0.0) v->farClip = 0.0;
        if (v->farClip > 1.0) v->farClip = 1.0;

        DIRTY(vb->depth, g->neg_bitid);
        DIRTY(vb->dirty, g->neg_bitid);
        DIRTY(tb->dirty, g->neg_bitid);
}

void STATE_APIENTRY crStateScissor (GLint x, GLint y, 
                                         GLsizei width, GLsizei height) 
{
        CRContext *g = GetCurrentContext();
        CRViewportState *v = &(g->viewport);
        CRStateBits *sb = GetCurrentBits();
        CRViewportBits *vb = &(sb->viewport);

        if (g->current.inBeginEnd) 
        {
                crStateError(__LINE__, __FILE__, GL_INVALID_OPERATION,
                        "glScissor called in begin/end");
                return;
        }

        FLUSH();

        if (width < 0 || height < 0)
        {
                crStateError(__LINE__, __FILE__, GL_INVALID_VALUE,
                        "glScissor called with negative width/height: %d,%d",
                        width, height);
                return;
        }

        v->scissorX = (GLint) (x);
        v->scissorY = (GLint) (y);
        v->scissorW = (GLint) (width);
        v->scissorH = (GLint) (height);

        v->scissorValid = GL_TRUE;

        DIRTY(vb->s_dims, g->neg_bitid);
        DIRTY(vb->dirty, g->neg_bitid);
}