glutil.c

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/*
 * $Id: glutil.c 38978 2011-08-03 09:28:16Z campbellbarton $
 *
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version. 
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 *
 * Contributor(s): Blender Foundation
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include <stdio.h>
#include <string.h>

#include "MEM_guardedalloc.h"

#include "DNA_vec_types.h"

#include "BLI_utildefines.h"

#include "BKE_colortools.h"

#include "BLI_math.h"
#include "BLI_threads.h"

#include "BIF_gl.h"
#include "BIF_glutil.h"

#ifndef GL_CLAMP_TO_EDGE
#define GL_CLAMP_TO_EDGE                        0x812F
#endif


/* ******************************************** */

/* defined in BIF_gl.h */
GLubyte stipple_halftone[128] = {
        0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
        0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
        0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
        0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
        0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
        0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
        0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
        0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
        0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
        0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
        0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
        0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
        0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
        0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 
        0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
        0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55};


/*  repeat this pattern
        X000X000
        00000000
        00X000X0
        00000000 */


GLubyte stipple_quarttone[128] = { 
        136,136,136,136,0,0,0,0,34,34,34,34,0,0,0,0,
        136,136,136,136,0,0,0,0,34,34,34,34,0,0,0,0,
        136,136,136,136,0,0,0,0,34,34,34,34,0,0,0,0,
        136,136,136,136,0,0,0,0,34,34,34,34,0,0,0,0,
        136,136,136,136,0,0,0,0,34,34,34,34,0,0,0,0,
        136,136,136,136,0,0,0,0,34,34,34,34,0,0,0,0,
        136,136,136,136,0,0,0,0,34,34,34,34,0,0,0,0,
        136,136,136,136,0,0,0,0,34,34,34,34,0,0,0,0};


GLubyte stipple_diag_stripes_pos[128] = {
    0x00, 0xff, 0x00, 0xff, 0x01, 0xfe, 0x01, 0xfe,
        0x03, 0xfc, 0x03, 0xfc, 0x07, 0xf8, 0x07, 0xf8,
        0x0f, 0xf0, 0x0f, 0xf0, 0x1f, 0xe0, 0x1f, 0xe0,
        0x3f, 0xc0, 0x3f, 0xc0, 0x7f, 0x80, 0x7f, 0x80,
        0xff, 0x00, 0xff, 0x00, 0xfe, 0x01, 0xfe, 0x01,
        0xfc, 0x03, 0xfc, 0x03, 0xf8, 0x07, 0xf8, 0x07,
        0xf0, 0x0f, 0xf0, 0x0f, 0xe0, 0x1f, 0xe0, 0x1f,
        0xc0, 0x3f, 0xc0, 0x3f, 0x80, 0x7f, 0x80, 0x7f,
        0x00, 0xff, 0x00, 0xff, 0x01, 0xfe, 0x01, 0xfe,
        0x03, 0xfc, 0x03, 0xfc, 0x07, 0xf8, 0x07, 0xf8,
        0x0f, 0xf0, 0x0f, 0xf0, 0x1f, 0xe0, 0x1f, 0xe0,
        0x3f, 0xc0, 0x3f, 0xc0, 0x7f, 0x80, 0x7f, 0x80,
        0xff, 0x00, 0xff, 0x00, 0xfe, 0x01, 0xfe, 0x01,
        0xfc, 0x03, 0xfc, 0x03, 0xf8, 0x07, 0xf8, 0x07,
        0xf0, 0x0f, 0xf0, 0x0f, 0xe0, 0x1f, 0xe0, 0x1f,
        0xc0, 0x3f, 0xc0, 0x3f, 0x80, 0x7f, 0x80, 0x7f};


GLubyte stipple_diag_stripes_neg[128] = {
    0xff, 0x00, 0xff, 0x00, 0xfe, 0x01, 0xfe, 0x01,
        0xfc, 0x03, 0xfc, 0x03, 0xf8, 0x07, 0xf8, 0x07,
        0xf0, 0x0f, 0xf0, 0x0f, 0xe0, 0x1f, 0xe0, 0x1f,
        0xc0, 0x3f, 0xc0, 0x3f, 0x80, 0x7f, 0x80, 0x7f,
        0x00, 0xff, 0x00, 0xff, 0x01, 0xfe, 0x01, 0xfe,
        0x03, 0xfc, 0x03, 0xfc, 0x07, 0xf8, 0x07, 0xf8,
        0x0f, 0xf0, 0x0f, 0xf0, 0x1f, 0xe0, 0x1f, 0xe0,
        0x3f, 0xc0, 0x3f, 0xc0, 0x7f, 0x80, 0x7f, 0x80,
        0xff, 0x00, 0xff, 0x00, 0xfe, 0x01, 0xfe, 0x01,
        0xfc, 0x03, 0xfc, 0x03, 0xf8, 0x07, 0xf8, 0x07,
        0xf0, 0x0f, 0xf0, 0x0f, 0xe0, 0x1f, 0xe0, 0x1f,
        0xc0, 0x3f, 0xc0, 0x3f, 0x80, 0x7f, 0x80, 0x7f,
        0x00, 0xff, 0x00, 0xff, 0x01, 0xfe, 0x01, 0xfe,
        0x03, 0xfc, 0x03, 0xfc, 0x07, 0xf8, 0x07, 0xf8,
        0x0f, 0xf0, 0x0f, 0xf0, 0x1f, 0xe0, 0x1f, 0xe0,
        0x3f, 0xc0, 0x3f, 0xc0, 0x7f, 0x80, 0x7f, 0x80};


void fdrawbezier(float vec[4][3])
{
        float dist;
        float curve_res = 24, spline_step = 0.0f;
        
        dist= 0.5f*ABS(vec[0][0] - vec[3][0]);
        
        /* check direction later, for top sockets */
        vec[1][0]= vec[0][0]+dist;
        vec[1][1]= vec[0][1];
        
        vec[2][0]= vec[3][0]-dist;
        vec[2][1]= vec[3][1];
        /* we can reuse the dist variable here to increment the GL curve eval amount*/
        dist = 1.0f/curve_res;
        
        cpack(0x0);
        glMap1f(GL_MAP1_VERTEX_3, 0.0, 1.0, 3, 4, vec[0]);
        glBegin(GL_LINE_STRIP);
        while (spline_step < 1.000001f) {
                /*if(do_shaded)
                        UI_ThemeColorBlend(th_col1, th_col2, spline_step);*/
                glEvalCoord1f(spline_step);
                spline_step += dist;
        }
        glEnd();
}

void fdrawline(float x1, float y1, float x2, float y2)
{
        float v[2];
        
        glBegin(GL_LINE_STRIP);
        v[0] = x1; v[1] = y1;
        glVertex2fv(v);
        v[0] = x2; v[1] = y2;
        glVertex2fv(v);
        glEnd();
}

void fdrawbox(float x1, float y1, float x2, float y2)
{
        float v[2];
        
        glBegin(GL_LINE_STRIP);
        
        v[0] = x1; v[1] = y1;
        glVertex2fv(v);
        v[0] = x1; v[1] = y2;
        glVertex2fv(v);
        v[0] = x2; v[1] = y2;
        glVertex2fv(v);
        v[0] = x2; v[1] = y1;
        glVertex2fv(v);
        v[0] = x1; v[1] = y1;
        glVertex2fv(v);
        
        glEnd();
}

void sdrawline(short x1, short y1, short x2, short y2)
{
        short v[2];
        
        glBegin(GL_LINE_STRIP);
        v[0] = x1; v[1] = y1;
        glVertex2sv(v);
        v[0] = x2; v[1] = y2;
        glVertex2sv(v);
        glEnd();
}

/*

        x1,y2
        |  \
        |   \
        |    \
        x1,y1-- x2,y1

*/

static void sdrawtripoints(short x1, short y1, short x2, short y2)
{
        short v[2];
        v[0]= x1; v[1]= y1;
        glVertex2sv(v);
        v[0]= x1; v[1]= y2;
        glVertex2sv(v);
        v[0]= x2; v[1]= y1;
        glVertex2sv(v);
}

void sdrawtri(short x1, short y1, short x2, short y2)
{
        glBegin(GL_LINE_STRIP);
        sdrawtripoints(x1, y1, x2, y2);
        glEnd();
}

void sdrawtrifill(short x1, short y1, short x2, short y2)
{
        glBegin(GL_TRIANGLES);
        sdrawtripoints(x1, y1, x2, y2);
        glEnd();
}

void sdrawbox(short x1, short y1, short x2, short y2)
{
        short v[2];
        
        glBegin(GL_LINE_STRIP);
        
        v[0] = x1; v[1] = y1;
        glVertex2sv(v);
        v[0] = x1; v[1] = y2;
        glVertex2sv(v);
        v[0] = x2; v[1] = y2;
        glVertex2sv(v);
        v[0] = x2; v[1] = y1;
        glVertex2sv(v);
        v[0] = x1; v[1] = y1;
        glVertex2sv(v);
        
        glEnd();
}


/* ******************************************** */

void setlinestyle(int nr)
{
        if(nr==0) {
                glDisable(GL_LINE_STIPPLE);
        }
        else {
                
                glEnable(GL_LINE_STIPPLE);
                glLineStipple(nr, 0xAAAA);
        }
}

        /* Invert line handling */
        
#define glToggle(mode, onoff)   (((onoff)?glEnable:glDisable)(mode))

void set_inverted_drawing(int enable) 
{
        glLogicOp(enable?GL_INVERT:GL_COPY);

        /* Use GL_BLEND_EQUATION_EXT on sgi (if we have it),
         * apparently GL_COLOR_LOGIC_OP doesn't work on O2?
         * Is this an sgi bug or our bug?
         */
#if defined(__sgi) && defined(GL_BLEND_EQUATION_EXT)
        glBlendEquationEXT(enable?GL_LOGIC_OP:GL_FUNC_ADD_EXT);
        glToggle(GL_BLEND, enable);
#else
        glToggle(GL_COLOR_LOGIC_OP, enable);
#endif

        glToggle(GL_DITHER, !enable);
}

void sdrawXORline(int x0, int y0, int x1, int y1)
{
        if(x0==x1 && y0==y1) return;

        set_inverted_drawing(1);
        
        glBegin(GL_LINES);
        glVertex2i(x0, y0);
        glVertex2i(x1, y1);
        glEnd();
        
        set_inverted_drawing(0);
}

void sdrawXORline4(int nr, int x0, int y0, int x1, int y1)
{
        static short old[4][2][2];
        static char flags[4]= {0, 0, 0, 0};
        
                /* with builtin memory, max 4 lines */

        set_inverted_drawing(1);
                
        glBegin(GL_LINES);
        if(nr== -1) { /* flush */
                for (nr=0; nr<4; nr++) {
                        if (flags[nr]) {
                                glVertex2sv(old[nr][0]);
                                glVertex2sv(old[nr][1]);
                                flags[nr]= 0;
                        }
                }
        } else {
                if(nr>=0 && nr<4) {
                        if(flags[nr]) {
                                glVertex2sv(old[nr][0]);
                                glVertex2sv(old[nr][1]);
                        }

                        old[nr][0][0]= x0;
                        old[nr][0][1]= y0;
                        old[nr][1][0]= x1;
                        old[nr][1][1]= y1;
                        
                        flags[nr]= 1;
                }
                
                glVertex2i(x0, y0);
                glVertex2i(x1, y1);
        }
        glEnd();
        
        set_inverted_drawing(0);
}

void fdrawXORellipse(float xofs, float yofs, float hw, float hh)
{
        if(hw==0) return;

        set_inverted_drawing(1);

        glPushMatrix();
        glTranslatef(xofs, yofs, 0.0);
        glScalef(1,hh/hw,1);
        glutil_draw_lined_arc(0.0, M_PI*2.0, hw, 20);
        glPopMatrix();

        set_inverted_drawing(0);
}
void fdrawXORcirc(float xofs, float yofs, float rad)
{
        set_inverted_drawing(1);

        glPushMatrix();
        glTranslatef(xofs, yofs, 0.0);
        glutil_draw_lined_arc(0.0, M_PI*2.0, rad, 20);
        glPopMatrix();

        set_inverted_drawing(0);
}

void glutil_draw_filled_arc(float start, float angle, float radius, int nsegments) {
        int i;
        
        glBegin(GL_TRIANGLE_FAN);
        glVertex2f(0.0, 0.0);
        for (i=0; i<nsegments; i++) {
                float t= (float) i/(nsegments-1);
                float cur= start + t*angle;
                
                glVertex2f(cosf(cur)*radius, sinf(cur)*radius);
        }
        glEnd();
}

void glutil_draw_lined_arc(float start, float angle, float radius, int nsegments) {
        int i;
        
        glBegin(GL_LINE_STRIP);
        for (i=0; i<nsegments; i++) {
                float t= (float) i/(nsegments-1);
                float cur= start + t*angle;
                
                glVertex2f(cosf(cur)*radius, sinf(cur)*radius);
        }
        glEnd();
}

int glaGetOneInteger(int param)
{
        GLint i;
        glGetIntegerv(param, &i);
        return i;
}

float glaGetOneFloat(int param)
{
        GLfloat v;
        glGetFloatv(param, &v);
        return v;
}

void glaRasterPosSafe2f(float x, float y, float known_good_x, float known_good_y)
{
        GLubyte dummy= 0;

                /* As long as known good coordinates are correct
                 * this is guarenteed to generate an ok raster
                 * position (ignoring potential (real) overflow
                 * issues).
                 */
        glRasterPos2f(known_good_x, known_good_y);

                /* Now shift the raster position to where we wanted
                 * it in the first place using the glBitmap trick.
                 */
        glBitmap(0, 0, 0, 0, x - known_good_x, y - known_good_y, &dummy);
}

static int get_cached_work_texture(int *w_r, int *h_r)
{
        static GLint texid= -1;
        static int tex_w= 256;
        static int tex_h= 256;

        if (texid==-1) {
                GLint ltexid= glaGetOneInteger(GL_TEXTURE_2D);
                unsigned char *tbuf;

                glGenTextures(1, (GLuint *)&texid);

                glBindTexture(GL_TEXTURE_2D, texid);

                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
                glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

                tbuf= MEM_callocN(tex_w*tex_h*4, "tbuf");
                glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, tex_w, tex_h, 0, GL_RGBA, GL_UNSIGNED_BYTE, tbuf);
                MEM_freeN(tbuf);

                glBindTexture(GL_TEXTURE_2D, ltexid);
        }

        *w_r= tex_w;
        *h_r= tex_h;
        return texid;
}

void glaDrawPixelsTexScaled(float x, float y, int img_w, int img_h, int format, void *rect, float scaleX, float scaleY)
{
        unsigned char *uc_rect= (unsigned char*) rect;
        float *f_rect= (float *)rect;
        float xzoom= glaGetOneFloat(GL_ZOOM_X), yzoom= glaGetOneFloat(GL_ZOOM_Y);
        int ltexid= glaGetOneInteger(GL_TEXTURE_2D);
        int lrowlength= glaGetOneInteger(GL_UNPACK_ROW_LENGTH);
        int subpart_x, subpart_y, tex_w, tex_h;
        int seamless, offset_x, offset_y, nsubparts_x, nsubparts_y;
        int texid= get_cached_work_texture(&tex_w, &tex_h);
        
        /* Specify the color outside this function, and tex will modulate it.
         * This is useful for changing alpha without using glPixelTransferf()
         */
        glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
        glPixelStorei(GL_UNPACK_ROW_LENGTH, img_w);
        glBindTexture(GL_TEXTURE_2D, texid);

        /* don't want nasty border artifacts */
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

#ifdef __APPLE__
        /* workaround for os x 10.5/10.6 driver bug: http://lists.apple.com/archives/Mac-opengl/2008/Jul/msg00117.html */
        glPixelZoom(1.f, 1.f);
#endif
        
        /* setup seamless 2=on, 0=off */
        seamless= ((tex_w<img_w || tex_h<img_h) && tex_w>2 && tex_h>2)? 2: 0;
        
        offset_x= tex_w - seamless;
        offset_y= tex_h - seamless;
        
        nsubparts_x= (img_w + (offset_x - 1))/(offset_x);
        nsubparts_y= (img_h + (offset_y - 1))/(offset_y);

        for (subpart_y=0; subpart_y<nsubparts_y; subpart_y++) {
                for (subpart_x=0; subpart_x<nsubparts_x; subpart_x++) {
                        int remainder_x= img_w-subpart_x*offset_x;
                        int remainder_y= img_h-subpart_y*offset_y;
                        int subpart_w= (remainder_x<tex_w)? remainder_x: tex_w;
                        int subpart_h= (remainder_y<tex_h)? remainder_y: tex_h;
                        int offset_left= (seamless && subpart_x!=0)? 1: 0;
                        int offset_bot= (seamless && subpart_y!=0)? 1: 0;
                        int offset_right= (seamless && remainder_x>tex_w)? 1: 0;
                        int offset_top= (seamless && remainder_y>tex_h)? 1: 0;
                        float rast_x= x+subpart_x*offset_x*xzoom;
                        float rast_y= y+subpart_y*offset_y*yzoom;
                        
                        /* check if we already got these because we always get 2 more when doing seamless*/
                        if(subpart_w<=seamless || subpart_h<=seamless)
                                continue;
                        
                        if(format==GL_FLOAT) {
                                glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, subpart_w, subpart_h, GL_RGBA, GL_FLOAT, &f_rect[subpart_y*offset_y*img_w*4 + subpart_x*offset_x*4]);
                                
                                /* add an extra border of pixels so linear looks ok at edges of full image. */
                                if(subpart_w<tex_w)
                                        glTexSubImage2D(GL_TEXTURE_2D, 0, subpart_w, 0, 1, subpart_h, GL_RGBA, GL_FLOAT, &f_rect[subpart_y*offset_y*img_w*4 + (subpart_x*offset_x+subpart_w-1)*4]);
                                if(subpart_h<tex_h)
                                        glTexSubImage2D(GL_TEXTURE_2D, 0, 0, subpart_h, subpart_w, 1, GL_RGBA, GL_FLOAT, &f_rect[(subpart_y*offset_y+subpart_h-1)*img_w*4 + subpart_x*offset_x*4]);
                                if(subpart_w<tex_w && subpart_h<tex_h)
                                        glTexSubImage2D(GL_TEXTURE_2D, 0, subpart_w, subpart_h, 1, 1, GL_RGBA, GL_FLOAT, &f_rect[(subpart_y*offset_y+subpart_h-1)*img_w*4 + (subpart_x*offset_x+subpart_w-1)*4]);
                        }
                        else {
                                glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, subpart_w, subpart_h, GL_RGBA, GL_UNSIGNED_BYTE, &uc_rect[subpart_y*offset_y*img_w*4 + subpart_x*offset_x*4]);
                                
                                if(subpart_w<tex_w)
                                        glTexSubImage2D(GL_TEXTURE_2D, 0, subpart_w, 0, 1, subpart_h, GL_RGBA, GL_UNSIGNED_BYTE, &uc_rect[subpart_y*offset_y*img_w*4 + (subpart_x*offset_x+subpart_w-1)*4]);
                                if(subpart_h<tex_h)
                                        glTexSubImage2D(GL_TEXTURE_2D, 0, 0, subpart_h, subpart_w, 1, GL_RGBA, GL_UNSIGNED_BYTE, &uc_rect[(subpart_y*offset_y+subpart_h-1)*img_w*4 + subpart_x*offset_x*4]);
                                if(subpart_w<tex_w && subpart_h<tex_h)
                                        glTexSubImage2D(GL_TEXTURE_2D, 0, subpart_w, subpart_h, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, &uc_rect[(subpart_y*offset_y+subpart_h-1)*img_w*4 + (subpart_x*offset_x+subpart_w-1)*4]);
                        }

                        glEnable(GL_TEXTURE_2D);
                        glBegin(GL_QUADS);
                        glTexCoord2f((float)(0 + offset_left)/tex_w, (float)(0 + offset_bot)/tex_h);
                        glVertex2f(rast_x + (float)offset_left*xzoom, rast_y + (float)offset_bot*xzoom);

                        glTexCoord2f((float)(subpart_w - offset_right)/tex_w, (float)(0 + offset_bot)/tex_h);
                        glVertex2f(rast_x + (float)(subpart_w - offset_right)*xzoom*scaleX, rast_y + (float)offset_bot*xzoom);

                        glTexCoord2f((float)(subpart_w - offset_right)/tex_w, (float)(subpart_h - offset_top)/tex_h);
                        glVertex2f(rast_x + (float)(subpart_w - offset_right)*xzoom*scaleX, rast_y + (float)(subpart_h - offset_top)*yzoom*scaleY);

                        glTexCoord2f((float)(0 + offset_left)/tex_w, (float)(subpart_h - offset_top)/tex_h);
                        glVertex2f(rast_x + (float)offset_left*xzoom, rast_y + (float)(subpart_h - offset_top)*yzoom*scaleY);
                        glEnd();
                        glDisable(GL_TEXTURE_2D);
                }
        }

        glBindTexture(GL_TEXTURE_2D, ltexid);
        glPixelStorei(GL_UNPACK_ROW_LENGTH, lrowlength);
        glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
        
#ifdef __APPLE__
        /* workaround for os x 10.5/10.6 driver bug (above) */
        glPixelZoom(xzoom, yzoom);
#endif
}

void glaDrawPixelsTex(float x, float y, int img_w, int img_h, int format, void *rect)
{
        glaDrawPixelsTexScaled(x, y, img_w, img_h, format, rect, 1.0f, 1.0f);
}

/* row_w is unused but kept for completeness */
void glaDrawPixelsSafe_to32(float fx, float fy, int img_w, int img_h, int UNUSED(row_w), float *rectf, int do_gamma_correct)
{
        unsigned char *rect32;
        
        /* copy imgw-imgh to a temporal 32 bits rect */
        if(img_w<1 || img_h<1) return;
        
        rect32= MEM_mallocN(img_w*img_h*sizeof(int), "temp 32 bits");
        
        if (do_gamma_correct) {
                floatbuf_to_srgb_byte(rectf, rect32, 0, img_w, 0, img_h, img_w);
        } else {
                floatbuf_to_byte(rectf, rect32, 0, img_w, 0, img_h, img_w);
         }
        
        glaDrawPixelsSafe(fx, fy, img_w, img_h, img_w, GL_RGBA, GL_UNSIGNED_BYTE, rect32);

        MEM_freeN(rect32);
}

void glaDrawPixelsSafe(float x, float y, int img_w, int img_h, int row_w, int format, int type, void *rect)
{
        float xzoom= glaGetOneFloat(GL_ZOOM_X);
        float yzoom= glaGetOneFloat(GL_ZOOM_Y);
                
                /* The pixel space coordinate of the intersection of
                 * the [zoomed] image with the origin.
                 */
        float ix= -x/xzoom;
        float iy= -y/yzoom;
        
                /* The maximum pixel amounts the image can be cropped
                 * at the lower left without exceeding the origin.
                 */
        int off_x= floor(MAX2(ix, 0));
        int off_y= floor(MAX2(iy, 0));
                
                /* The zoomed space coordinate of the raster position 
                 * (starting at the lower left most unclipped pixel).
                 */
        float rast_x= x + off_x*xzoom;
        float rast_y= y + off_y*yzoom;

        GLfloat scissor[4];
        int draw_w, draw_h;

                /* Determine the smallest number of pixels we need to draw
                 * before the image would go off the upper right corner.
                 * 
                 * It may seem this is just an optimization but some graphics 
                 * cards (ATI) freak out if there is a large zoom factor and
                 * a large number of pixels off the screen (probably at some
                 * level the number of image pixels to draw is getting multiplied
                 * by the zoom and then clamped). Making sure we draw the
                 * fewest pixels possible keeps everyone mostly happy (still
                 * fails if we zoom in on one really huge pixel so that it
                 * covers the entire screen).
                 */
        glGetFloatv(GL_SCISSOR_BOX, scissor);
        draw_w = MIN2(img_w-off_x, ceil((scissor[2]-rast_x)/xzoom));
        draw_h = MIN2(img_h-off_y, ceil((scissor[3]-rast_y)/yzoom));

        if (draw_w>0 && draw_h>0) {
                int old_row_length = glaGetOneInteger(GL_UNPACK_ROW_LENGTH);

                        /* Don't use safe RasterPos (slower) if we can avoid it. */
                if (rast_x>=0 && rast_y>=0) {
                        glRasterPos2f(rast_x, rast_y);
                } else {
                        glaRasterPosSafe2f(rast_x, rast_y, 0, 0);
                }

                glPixelStorei(GL_UNPACK_ROW_LENGTH, row_w);
                if(format==GL_LUMINANCE || format==GL_RED) {
                        if(type==GL_FLOAT) {
                                float *f_rect= (float *)rect;
                                glDrawPixels(draw_w, draw_h, format, type, f_rect + (off_y*row_w + off_x));
                        }
                        else if(type==GL_INT || type==GL_UNSIGNED_INT) {
                                int *i_rect= (int *)rect;
                                glDrawPixels(draw_w, draw_h, format, type, i_rect + (off_y*row_w + off_x));
                        }
                }
                else { /* RGBA */
                        if(type==GL_FLOAT) {
                                float *f_rect= (float *)rect;
                                glDrawPixels(draw_w, draw_h, format, type, f_rect + (off_y*row_w + off_x)*4);
                        }
                        else if(type==GL_UNSIGNED_BYTE) {
                                unsigned char *uc_rect= (unsigned char *) rect;
                                glDrawPixels(draw_w, draw_h, format, type, uc_rect + (off_y*row_w + off_x)*4);
                        }
                }
                
                glPixelStorei(GL_UNPACK_ROW_LENGTH,  old_row_length);
        }
}

/* 2D Drawing Assistance */

void glaDefine2DArea(rcti *screen_rect)
{
        int sc_w= screen_rect->xmax - screen_rect->xmin + 1;
        int sc_h= screen_rect->ymax - screen_rect->ymin + 1;

        glViewport(screen_rect->xmin, screen_rect->ymin, sc_w, sc_h);
        glScissor(screen_rect->xmin, screen_rect->ymin, sc_w, sc_h);

                /* The 0.375 magic number is to shift the matrix so that
                 * both raster and vertex integer coordinates fall at pixel
                 * centers properly. For a longer discussion see the OpenGL
                 * Programming Guide, Appendix H, Correctness Tips.
                 */

        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        glOrtho(0.0, sc_w, 0.0, sc_h, -1, 1);
        glTranslatef(0.375, 0.375, 0.0);

        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();
}

struct gla2DDrawInfo {
        int orig_vp[4], orig_sc[4];
        float orig_projmat[16], orig_viewmat[16];

        rcti screen_rect;
        rctf world_rect;

        float wo_to_sc[2];
};

void gla2DGetMap(gla2DDrawInfo *di, rctf *rect) 
{
        *rect= di->world_rect;
}

void gla2DSetMap(gla2DDrawInfo *di, rctf *rect) 
{
        int sc_w, sc_h;
        float wo_w, wo_h;

        di->world_rect= *rect;
        
        sc_w= (di->screen_rect.xmax-di->screen_rect.xmin);
        sc_h= (di->screen_rect.ymax-di->screen_rect.ymin);
        wo_w= (di->world_rect.xmax-di->world_rect.xmin);
        wo_h= (di->world_rect.ymax-di->world_rect.ymin);
        
        di->wo_to_sc[0]= sc_w/wo_w;
        di->wo_to_sc[1]= sc_h/wo_h;
}


gla2DDrawInfo *glaBegin2DDraw(rcti *screen_rect, rctf *world_rect) 
{
        gla2DDrawInfo *di= MEM_mallocN(sizeof(*di), "gla2DDrawInfo");
        int sc_w, sc_h;
        float wo_w, wo_h;

        glGetIntegerv(GL_VIEWPORT, (GLint *)di->orig_vp);
        glGetIntegerv(GL_SCISSOR_BOX, (GLint *)di->orig_sc);
        glGetFloatv(GL_PROJECTION_MATRIX, (GLfloat *)di->orig_projmat);
        glGetFloatv(GL_MODELVIEW_MATRIX, (GLfloat *)di->orig_viewmat);

        di->screen_rect= *screen_rect;
        if (world_rect) {
                di->world_rect= *world_rect;
        } else {
                di->world_rect.xmin= di->screen_rect.xmin;
                di->world_rect.ymin= di->screen_rect.ymin;
                di->world_rect.xmax= di->screen_rect.xmax;
                di->world_rect.ymax= di->screen_rect.ymax;
        }

        sc_w= (di->screen_rect.xmax-di->screen_rect.xmin);
        sc_h= (di->screen_rect.ymax-di->screen_rect.ymin);
        wo_w= (di->world_rect.xmax-di->world_rect.xmin);
        wo_h= (di->world_rect.ymax-di->world_rect.ymin);

        di->wo_to_sc[0]= sc_w/wo_w;
        di->wo_to_sc[1]= sc_h/wo_h;

        glaDefine2DArea(&di->screen_rect);

        return di;
}

void gla2DDrawTranslatePt(gla2DDrawInfo *di, float wo_x, float wo_y, int *sc_x_r, int *sc_y_r)
{
        *sc_x_r= (wo_x - di->world_rect.xmin)*di->wo_to_sc[0];
        *sc_y_r= (wo_y - di->world_rect.ymin)*di->wo_to_sc[1];
}
void gla2DDrawTranslatePtv(gla2DDrawInfo *di, float world[2], int screen_r[2])
{
        screen_r[0]= (world[0] - di->world_rect.xmin)*di->wo_to_sc[0];
        screen_r[1]= (world[1] - di->world_rect.ymin)*di->wo_to_sc[1];
}

void glaEnd2DDraw(gla2DDrawInfo *di)
{
        glViewport(di->orig_vp[0], di->orig_vp[1], di->orig_vp[2], di->orig_vp[3]);
        glScissor(di->orig_vp[0], di->orig_vp[1], di->orig_vp[2], di->orig_vp[3]);
        glMatrixMode(GL_PROJECTION);
        glLoadMatrixf(di->orig_projmat);
        glMatrixMode(GL_MODELVIEW);
        glLoadMatrixf(di->orig_viewmat);

        MEM_freeN(di);
}

/* **************** glPoint hack ************************ */

static int curmode=0;
static int pointhack=0;
static GLubyte Squaredot[16] = { 0xff,0xff,0xff,0xff,
                                                                 0xff,0xff,0xff,0xff,
                                                                 0xff,0xff,0xff,0xff, 
                                                                 0xff,0xff,0xff,0xff};

void bglBegin(int mode)
{
        curmode= mode;
        
        if(mode==GL_POINTS) {
                float value[4];
                glGetFloatv(GL_POINT_SIZE_RANGE, value);
                if(value[1] < 2.0f) {
                        glGetFloatv(GL_POINT_SIZE, value);
                        pointhack= floor(value[0] + 0.5f);
                        if(pointhack>4) pointhack= 4;
                }
                else glBegin(mode);
        }
}

int bglPointHack(void) {
        float value[4];
        int pointhack_px;
        glGetFloatv(GL_POINT_SIZE_RANGE, value);
        if(value[1] < 2.0f) {
                glGetFloatv(GL_POINT_SIZE, value);
                pointhack_px= floorf(value[0]+0.5f);
                if(pointhack_px>4) pointhack_px= 4;
                return pointhack_px;
        }
        return 0;
}

void bglVertex3fv(float *vec)
{
        switch(curmode) {
        case GL_POINTS:
                if(pointhack) {
                        glRasterPos3fv(vec);
                        glBitmap(pointhack, pointhack, (float)pointhack/2.0f, (float)pointhack/2.0f, 0.0, 0.0, Squaredot);
                }
                else glVertex3fv(vec);
                break;
        }
}

void bglVertex3f(float x, float y, float z)
{
        switch(curmode) {
        case GL_POINTS:
                if(pointhack) {
                        glRasterPos3f(x, y, z);
                        glBitmap(pointhack, pointhack, (float)pointhack/2.0f, (float)pointhack/2.0f, 0.0, 0.0, Squaredot);
                }
                else glVertex3f(x, y, z);
                break;
        }
}

void bglVertex2fv(float *vec)
{
        switch(curmode) {
        case GL_POINTS:
                if(pointhack) {
                        glRasterPos2fv(vec);
                        glBitmap(pointhack, pointhack, (float)pointhack/2, pointhack/2, 0.0, 0.0, Squaredot);
                }
                else glVertex2fv(vec);
                break;
        }
}


void bglEnd(void)
{
        if(pointhack) pointhack= 0;
        else glEnd();
        
}

/* Uses current OpenGL state to get view matrices for gluProject/gluUnProject */
void bgl_get_mats(bglMats *mats)
{
        const double badvalue= 1.0e-6;

        glGetDoublev(GL_MODELVIEW_MATRIX, mats->modelview);
        glGetDoublev(GL_PROJECTION_MATRIX, mats->projection);
        glGetIntegerv(GL_VIEWPORT, (GLint *)mats->viewport);
        
        /* Very strange code here - it seems that certain bad values in the
           modelview matrix can cause gluUnProject to give bad results. */
        if(mats->modelview[0] < badvalue &&
           mats->modelview[0] > -badvalue)
                mats->modelview[0]= 0;
        if(mats->modelview[5] < badvalue &&
           mats->modelview[5] > -badvalue)
                mats->modelview[5]= 0;
        
        /* Set up viewport so that gluUnProject will give correct values */
        mats->viewport[0] = 0;
        mats->viewport[1] = 0;
}

/* *************** glPolygonOffset hack ************* */

/* dist is only for ortho now... */
void bglPolygonOffset(float viewdist, float dist) 
{
        static float winmat[16], offset=0.0;    
        
        if(dist != 0.0f) {
                float offs;
                
                // glEnable(GL_POLYGON_OFFSET_FILL);
                // glPolygonOffset(-1.0, -1.0);

                /* hack below is to mimic polygon offset */
                glMatrixMode(GL_PROJECTION);
                glGetFloatv(GL_PROJECTION_MATRIX, (float *)winmat);
                
                /* dist is from camera to center point */
                
                if(winmat[15]>0.5f) offs= 0.00001f*dist*viewdist;  // ortho tweaking
                else offs= 0.0005f*dist;  // should be clipping value or so...
                
                winmat[14]-= offs;
                offset+= offs;
                
                glLoadMatrixf(winmat);
                glMatrixMode(GL_MODELVIEW);
        }
        else {

                glMatrixMode(GL_PROJECTION);
                winmat[14]+= offset;
                offset= 0.0;
                glLoadMatrixf(winmat);
                glMatrixMode(GL_MODELVIEW);
        }
}

void bglFlush(void) 
{
        glFlush();
#ifdef __APPLE__
//      if(GPU_type_matches(GPU_DEVICE_INTEL, GPU_OS_MAC, GPU_DRIVER_OFFICIAL))
// XXX          myswapbuffers(); //hack to get mac intel graphics to show frontbuffer
#endif
}