fltk/src/Fl_Graphics_Driver.cxx

//
// "$Id$"
//
// implementation of Fl_Graphics_Driver class for the Fast Light Tool Kit (FLTK).
//
// Copyright 2010-2017 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file.  If this
// file is missing or damaged, see the license at:
//
//     http://www.fltk.org/COPYING.php
//
// Please report all bugs and problems to:
//
//     http://www.fltk.org/str.php
//

#include <FL/Fl.H>
#include "config_lib.h"
#include <FL/Fl_Graphics_Driver.H>
#include <FL/Fl_Screen_Driver.H>
#include <FL/Fl_Image.H>
#include <FL/fl_draw.H>
#include <FL/Fl_Image_Surface.H>
#include <FL/math.h>
#include <FL/x.H>

FL_EXPORT Fl_Graphics_Driver *fl_graphics_driver; // the current driver of graphics operations

const Fl_Graphics_Driver::matrix Fl_Graphics_Driver::m0 = {1, 0, 0, 1, 0, 0};

/** Constructor */
Fl_Graphics_Driver::Fl_Graphics_Driver()
{
  font_ = 0;
  size_ = 0;
  sptr=0; rstackptr=0; 
  rstack[0] = NULL;
  fl_clip_state_number=0;
  m = m0; 
  fl_matrix = &m; 
  font_descriptor_ = NULL;
};

/** Return the graphics driver used when drawing to the platform's display */
Fl_Graphics_Driver &Fl_Graphics_Driver::default_driver()
{
  static Fl_Graphics_Driver *pMainDriver = Fl_Display_Device::display_device()->driver();
  return *pMainDriver;
}


/** see fl_text_extents() */
void Fl_Graphics_Driver::text_extents(const char*t, int n, int& dx, int& dy, int& w, int& h)
{
  w = (int)width(t, n);
  h = - height();
  dx = 0;
  dy = descent();
}

/** see fl_focus_rect() */
void Fl_Graphics_Driver::focus_rect(int x, int y, int w, int h)
{
  line_style(FL_DOT);
  rect(x, y, w, h);
  line_style(FL_SOLID);
}

/** Draws an Fl_Image scaled to width \p W & height \p H with top-left corner at \em X,Y
 \return zero when the graphics driver doesn't implement scaled drawing, non-zero if it does implement it.
 */
int Fl_Graphics_Driver::draw_scaled(Fl_Image *img, int X, int Y, int W, int H) {
  return 0;
}

/** see fl_copy_offscreen() */
void Fl_Graphics_Driver::copy_offscreen(int x, int y, int w, int h, Fl_Offscreen pixmap, int srcx, int srcy)
{
  // This platform-independent version can be used by any graphics driver,
  // noticeably the PostScript driver.
  // More efficient platform-specific implementations exist for other graphics drivers.
  Fl_Image_Surface *surface = NULL;
  int px_width = w, px_height = h;
  Fl::screen_driver()->offscreen_size(pixmap, px_width, px_height);
  int px = srcx, py = srcy, pw = w, ph = h;
  if (px < 0) {px = 0; pw += srcx; x -= srcx;}
  if (py < 0) {py = 0; ph += srcy; y -= srcy;}
  if (px + pw > px_width) {pw = px_width - px;}
  if (py + ph > px_height) {ph = px_height - py;}
  Fl_Surface_Device *current = Fl_Surface_Device::surface();
  fl_begin_offscreen(pixmap);
  // test whether pixmap was not created by fl_create_offscreen()
  if (current == Fl_Surface_Device::surface()) {
    surface = new Fl_Image_Surface(px_width, px_height, 0, pixmap);
    Fl_Surface_Device::push_current(surface);
  }
  uchar *img = fl_read_image(NULL, px, py, pw, ph, 0);
  if (surface) {
    Fl_Surface_Device::pop_current();
    surface->get_offscreen_before_delete(); // so deleting surface does not touch pixmap
    delete surface;
  } else fl_end_offscreen();
  if (img) {
    fl_draw_image(img, x, y, pw, ph, 3, 0);
    delete[] img;
  }
}

/** see fl_set_spot() */
void Fl_Graphics_Driver::set_spot(int font, int size, int X, int Y, int W, int H, Fl_Window *win)
{
  // nothing to do, reimplement in driver if needed
}


/** see fl_reset_spot() */
void Fl_Graphics_Driver::reset_spot()
{
  // nothing to do, reimplement in driver if needed
}


/** Sets the value of the fl_gc global variable when it changes */
void Fl_Graphics_Driver::global_gc()
{
  // nothing to do, reimplement in driver if needed
}


/** see Fl::set_color(Fl_Color, unsigned) */
void Fl_Graphics_Driver::set_color(Fl_Color i, unsigned c)
{
  // nothing to do, reimplement in driver if needed
}


/** see Fl::free_color(Fl_Color, int) */
void Fl_Graphics_Driver::free_color(Fl_Color i, int overlay)
{
  // nothing to do, reimplement in driver if needed
}

/** Add a rectangle to an Fl_Region */
void Fl_Graphics_Driver::add_rectangle_to_region(Fl_Region r, int x, int y, int w, int h)
{
  // nothing to do, reimplement in driver if needed
}

/** Create a rectangular Fl_Region */
Fl_Region Fl_Graphics_Driver::XRectangleRegion(int x, int y, int w, int h)
{
  // nothing to do, reimplement in driver if needed
  return 0;
}

/** Delete an Fl_Region */
void Fl_Graphics_Driver::XDestroyRegion(Fl_Region r)
{
  // nothing to do, reimplement in driver if needed
}

/** Helper function for image drawing by platform-specific graphics drivers */
int Fl_Graphics_Driver::start_image(Fl_Image *img, int XP, int YP, int WP, int HP, int &cx, int &cy,
                     int &X, int &Y, int &W, int &H)
{
  // account for current clip region (faster on Irix):
  clip_box(XP,YP,WP,HP,X,Y,W,H);
  cx += X-XP; cy += Y-YP;
  // clip the box down to the size of image, quit if empty:
  if (cx < 0) {W += cx; X -= cx; cx = 0;}
  if (cx+W > img->w()) W = img->w()-cx;
  if (W <= 0) return 1;
  if (cy < 0) {H += cy; Y -= cy; cy = 0;}
  if (cy+H > img->h()) H = img->h()-cy;
  if (H <= 0) return 1;
  return 0;
}

/** Support function for image drawing */
void Fl_Graphics_Driver::uncache_pixmap(fl_uintptr_t p) {
  fl_delete_offscreen((Fl_Offscreen)p);
}


void Fl_Graphics_Driver::set_current_() {
}


/** Draws an Fl_Shared_Image object using this graphics driver.
 \param shared shared image to be drawn
 \param X,Y top-left position of the drawn image */
void Fl_Graphics_Driver::draw(Fl_Shared_Image *shared, int X, int Y) {
  if ( shared->w() == shared->image_->w() && shared->h() == shared->image_->h()) {
    shared->image_->draw(X, Y, shared->w(), shared->h(), 0, 0);
    return;
  }
  if ( shared->image_->draw_scaled_(X, Y, shared->w(), shared->h()) ) return;
  if (shared->scaled_image_ && (shared->scaled_image_->w() != shared->w() || shared->scaled_image_->h() != shared->h())) {
    delete shared->scaled_image_;
    shared->scaled_image_ = NULL;
  }
  if (!shared->scaled_image_) {
    Fl_RGB_Scaling previous = Fl_Shared_Image::RGB_scaling();
    Fl_Shared_Image::RGB_scaling(shared->scaling_algorithm_); // useless but no harm if image_ is not an Fl_RGB_Image
    shared->scaled_image_ = shared->image_->copy(shared->w(), shared->h());
    Fl_Shared_Image::RGB_scaling(previous);
  }
  shared->scaled_image_->draw(X, Y, shared->scaled_image_->w(), shared->scaled_image_->h(), 0, 0);
}


#ifndef FL_DOXYGEN
Fl_Scalable_Graphics_Driver::Fl_Scalable_Graphics_Driver() : Fl_Graphics_Driver() {
  scale_ = 1;
  line_width_ = 0;
}

void Fl_Scalable_Graphics_Driver::rect(int x, int y, int w, int h)
{
  rect_unscaled(x * scale_, y * scale_, w * scale_, h * scale_);
}

void Fl_Scalable_Graphics_Driver::rectf(int x, int y, int w, int h)
{
  rectf_unscaled(x * scale_, y * scale_, w * scale_, h * scale_);
}

void Fl_Scalable_Graphics_Driver::point(int x, int y) {
  point_unscaled(x * scale_, y * scale_);
}

void Fl_Scalable_Graphics_Driver::line(int x, int y, int x1, int y1) {
  line_unscaled( x*scale_, y*scale_, x1*scale_, y1*scale_);
}

void Fl_Scalable_Graphics_Driver::line(int x, int y, int x1, int y1, int x2, int y2) {
  line_unscaled( x*scale_, y*scale_, x1*scale_, y1*scale_, x2*scale_, y2*scale_);
}

void Fl_Scalable_Graphics_Driver::xyline(int x, int y, int x1) {
  xyline_unscaled(x*scale_, y*scale_, x1*scale_);
}
void Fl_Scalable_Graphics_Driver::xyline(int x, int y, int x1, int y2) {
  xyline_unscaled(x*scale_, y*scale_, x1*scale_, y2*scale_);
}
void Fl_Scalable_Graphics_Driver::xyline(int x, int y, int x1, int y2, int x3) {
  xyline_unscaled(x*scale_, y*scale_, x1*scale_, y2*scale_, x3*scale_);
}

void Fl_Scalable_Graphics_Driver::yxline(int x, int y, int y1) {
  yxline_unscaled(x*scale_, y*scale_, y1*scale_);
}
void Fl_Scalable_Graphics_Driver::yxline(int x, int y, int y1, int x2) {
  yxline_unscaled(x*scale_, y*scale_, y1*scale_, x2*scale_);
}
void Fl_Scalable_Graphics_Driver::yxline(int x, int y, int y1, int x2, int y3) {
  yxline_unscaled(x*scale_, y*scale_, y1*scale_, x2*scale_, y3*scale_);
}

void Fl_Scalable_Graphics_Driver::loop(int x0, int y0, int x1, int y1, int x2, int y2) {
  loop_unscaled(x0*scale_, y0*scale_, x1*scale_, y1*scale_, x2*scale_, y2*scale_);
}

void Fl_Scalable_Graphics_Driver::loop(int x0, int y0, int x1, int y1, int x2, int y2, int x3, int y3) {
  loop_unscaled(x0*scale_, y0*scale_, x1*scale_, y1*scale_, x2*scale_, y2*scale_, x3*scale_, y3*scale_);
}

void Fl_Scalable_Graphics_Driver::polygon(int x0, int y0, int x1, int y1, int x2, int y2) {
  polygon_unscaled(x0*scale_, y0*scale_, x1*scale_, y1*scale_, x2*scale_, y2*scale_);
}

void Fl_Scalable_Graphics_Driver::polygon(int x0, int y0, int x1, int y1, int x2, int y2, int x3, int y3) {
  polygon_unscaled(x0*scale_, y0*scale_, x1*scale_, y1*scale_, x2*scale_, y2*scale_, x3*scale_, y3*scale_);
}

void Fl_Scalable_Graphics_Driver::circle(double x, double y, double r) {
  double xt = transform_x(x,y);
  double yt = transform_y(x,y);
  double rx = r * (m.c ? sqrt(m.a*m.a+m.c*m.c) : fabs(m.a));
  double ry = r * (m.b ? sqrt(m.b*m.b+m.d*m.d) : fabs(m.d));
  ellipse_unscaled(xt*scale_, yt*scale_, rx*scale_, ry*scale_);
}

// compute width & height of cached image so it can be tiled without undrawn gaps when scaling output
void Fl_Scalable_Graphics_Driver::cache_size(Fl_Image *img, int &width, int &height)
{
  if ( int(scale_) == scale_ ) {
    width  = width * scale_;
    height = height * scale_;
  } else {
    width  = (width+1) * scale_;
    height = (height+1) * scale_;
  }
}


void Fl_Scalable_Graphics_Driver::draw(Fl_Pixmap *pxm, int XP, int YP, int WP, int HP, int cx, int cy) {
  int X, Y, W, H;
  if (Fl_Graphics_Driver::start_image(pxm, XP, YP, WP, HP, cx, cy, X, Y, W, H)) {
    return;
  }
  // to allow rescale at runtime
  if (*id(pxm)) {
    if (*cache_scale(pxm) != scale_) {
      pxm->uncache();
    }
  }
  if (!*id(pxm)) {
    if (scale_ != 1) { // build a scaled id_ & pixmap_ for pxm
      int w2=pxm->w(), h2=pxm->h();
      cache_size(pxm, w2, h2);
      Fl_Pixmap *pxm2 = (Fl_Pixmap*)pxm->copy(w2, h2);
      *id(pxm) = cache(pxm2, pxm2->w(), pxm2->h(), pxm2->data());
      *cache_scale(pxm) = scale_;
      *mask(pxm) = *mask(pxm2);
      *mask(pxm2) = 0;
      delete pxm2;
    } else *id(pxm) = cache(pxm, pxm->w(), pxm->h(), pxm->data());
  }
  // draw pxm using its scaled id_ & pixmap_
  draw_unscaled(pxm, scale_, X, Y, W, H, cx, cy);
}


void Fl_Scalable_Graphics_Driver::draw(Fl_Bitmap *bm, int XP, int YP, int WP, int HP, int cx, int cy) {
  int X, Y, W, H;
  if (Fl_Graphics_Driver::start_image(bm, XP, YP, WP, HP, cx, cy, X, Y, W, H)) {
    return;
  }
  if (*id(bm)) {
    if (*cache_scale(bm) != scale_) {
      bm->uncache();
    }
  }
  if (!*id(bm)) {
    if (scale_ != 1) { // build a scaled id_ for bm
      int w2 = bm->w(), h2 = bm->h();
      cache_size(bm, w2, h2);
      Fl_Bitmap *bm2 = (Fl_Bitmap*)bm->copy(w2, h2);
      *id(bm) = cache(bm2, bm2->w(), bm2->h(), bm2->array);
      *cache_scale(bm) =  scale_;
      delete bm2;
    } else *id(bm) = cache(bm, bm->w(), bm->h(), bm->array);
  }
  // draw bm using its scaled id_
  draw_unscaled(bm, scale_, X, Y, W, H, cx, cy);
}


void Fl_Scalable_Graphics_Driver::draw(Fl_RGB_Image *img, int XP, int YP, int WP, int HP, int cx, int cy) {
  // Don't draw an empty image...
  if (!img->d() || !img->array) {
    Fl_Graphics_Driver::draw_empty(img, XP, YP);
    return;
  }
  if (start_image(img, XP, YP, WP, HP, cx, cy, XP, YP, WP, HP)) {
    return;
  }
  if (scale() != 1 && can_do_alpha_blending()) { // try and use the system's scaled image drawing
    push_clip(XP, YP, WP, HP);
    int done = draw_scaled(img, XP-cx, YP-cy, img->w(), img->h());
    pop_clip();
    if (done) return;
  }
  // to allow rescale at runtime
  if (*id(img) && *cache_scale(img) != scale_) {
      img->uncache();
  }
  if (!*id(img) && scale_ != 1) { // build and draw a scaled id_ for img
    int w2=img->w(), h2=img->h();
    cache_size(img, w2, h2);
    Fl_RGB_Image *img2 = (Fl_RGB_Image*)img->copy(w2, h2);
    draw_unscaled(img2, scale_, XP, YP, WP, HP, cx, cy);
    *id(img) = *id(img2);
    *id(img2) = 0;
    *cache_scale(img) = scale_;
    delete img2;
  }
  else { // draw img using its scaled id_
    draw_unscaled(img, scale_, XP, YP, WP, HP, cx, cy);
  }
}


void Fl_Scalable_Graphics_Driver::draw(Fl_Shared_Image *shared, int X, int Y) {
  if (scale_ == 1) {
    Fl_Graphics_Driver::draw(shared, X, Y);
    return;
  }
  float s = scale_; scale_ = 1;
  Fl_Region r2 = scale_clip(s);
  int oldw=shared->w();
  int oldh=shared->h();
  change_image_size(shared, (oldw*s < 1 ? 1: int(oldw*s)), (oldh*s < 1 ? 1: int(oldh*s)));
  Fl_Graphics_Driver::draw(shared, X*s, Y*s);
  change_image_size(shared, oldw, oldh);
  unscale_clip(r2);
  scale_ = s;
}


void Fl_Scalable_Graphics_Driver::font(Fl_Font face, Fl_Fontsize size) {
  if (!font_descriptor()) fl_open_display(); // to catch the correct initial value of scale_
  font_unscaled(face, size * scale_);
}

double Fl_Scalable_Graphics_Driver::width(const char *str, int n) {
  return width_unscaled(str, n)/scale_;
}

double Fl_Scalable_Graphics_Driver::width(unsigned int c) {
  return width_unscaled(c)/scale_;
}

Fl_Fontsize Fl_Scalable_Graphics_Driver::size() {
  if (!font_descriptor() ) return -1;
  return size_unscaled()/scale_;
}

void Fl_Scalable_Graphics_Driver::text_extents(const char *str, int n, int &dx, int &dy, int &w, int &h) {
  text_extents_unscaled(str, n, dx, dy, w, h);
  dx /= scale_;
  dy /= scale_;
  w /= scale_;
  h /= scale_;
}

int Fl_Scalable_Graphics_Driver::height() {
  return int(height_unscaled()/scale_);
}

int Fl_Scalable_Graphics_Driver::descent() {
  return descent_unscaled()/scale_;
}

void Fl_Scalable_Graphics_Driver::draw(const char *str, int n, int x, int y) {
  if (!size_ || !font_descriptor()) font(FL_HELVETICA, FL_NORMAL_SIZE);
  Fl_Region r2 = scale_clip(scale_);
  draw_unscaled(str, n, x*scale_, y*scale_);
  unscale_clip(r2);
}

void Fl_Scalable_Graphics_Driver::draw(int angle, const char *str, int n, int x, int y) {
  if (!size_ || !font_descriptor()) font(FL_HELVETICA, FL_NORMAL_SIZE);
  Fl_Region r2 = scale_clip(scale_);
  draw_unscaled(angle, str, n, x*scale_, y*scale_);
  unscale_clip(r2);
}

void Fl_Scalable_Graphics_Driver::rtl_draw(const char* str, int n, int x, int y) {
  rtl_draw_unscaled(str, n, x * scale_, y * scale_);
}

void Fl_Scalable_Graphics_Driver::arc(int x,int y,int w,int h,double a1,double a2) {
  arc_unscaled(x * scale_, y * scale_, w * scale_, h * scale_, a1, a2);
}

void Fl_Scalable_Graphics_Driver::pie(int x,int y,int w,int h,double a1,double a2) {
  pie_unscaled(x * scale_, y * scale_, w * scale_, h * scale_, a1, a2);
}

void Fl_Scalable_Graphics_Driver::line_style(int style, int width, char* dashes) {
  if (width == 0) line_width_ = scale_ < 2 ? 0 : scale_;
  else line_width_ = width>0 ? width*scale_ : -width*scale_;
  line_style_unscaled(style, line_width_, dashes);
}

/* read the image data from a pointer or with a callback, scale it, and draw it */
void Fl_Scalable_Graphics_Driver::draw_image_rescale(void *buf, Fl_Draw_Image_Cb cb,
                                                     int X, int Y, int W, int H, int D, int L, bool mono, float s) {
  int aD = abs(D);
  if (L == 0) L = W*aD;
  int depth = mono ? (aD%2==0?2:1) : aD;
  uchar *tmp_buf = new uchar[W*H*depth];
  if (cb) {
    for (int i = 0; i < H; i++) {
      cb(buf, 0, i, W, tmp_buf + i * W * depth);
    }
  } else {
    uchar *q, *p = tmp_buf;
    for (int i = 0; i < H; i++) {
      q = (uchar*)buf + i * L;
      for (int j = 0; j < W; j++) {
        memcpy(p, q, depth);
        p += depth; q += D;
      }
    }
  }
  Fl_RGB_Image *rgb = new Fl_RGB_Image(tmp_buf, W, H, depth);
  rgb->alloc_array = 1;
  Fl_RGB_Image *scaled_rgb = (Fl_RGB_Image*)rgb->copy(ceil(W * s), ceil(H * s));
  delete rgb;
  if (scaled_rgb) {
    Fl_Region r2 = scale_clip(s);
    draw_image_unscaled(scaled_rgb->array, X * s, Y * s, scaled_rgb->w(), scaled_rgb->h(), depth);
    unscale_clip(r2);
    delete scaled_rgb;
  }
}

void Fl_Scalable_Graphics_Driver::draw_image(const uchar* buf, int X,int Y,int W,int H, int D, int L) {
  if (scale_ == 1) {
    draw_image_unscaled(buf, X,Y,W,H,D,L);
  } else {
    draw_image_rescale((void*)buf, NULL, X, Y, W, H, D, L, false, scale_);
  }
}

void Fl_Scalable_Graphics_Driver::draw_image(Fl_Draw_Image_Cb cb, void* data, int X,int Y,int W,int H, int D) {
  if (scale_ == 1) {
    draw_image_unscaled(cb, data, X,Y,W,H,D);
  } else {
    draw_image_rescale(data, cb, X, Y, W, H, D, 0, false, scale_);
  }
}

void Fl_Scalable_Graphics_Driver::draw_image_mono(const uchar* buf, int X,int Y,int W,int H, int D, int L) {
  if (scale_ == 1) {
    draw_image_mono_unscaled(buf, X,Y,W,H,D,L);
  } else {
    draw_image_rescale((void*)buf, NULL, X, Y, W, H, D, L, true, scale_);
  }
}

void Fl_Scalable_Graphics_Driver::draw_image_mono(Fl_Draw_Image_Cb cb, void* data, int X,int Y,int W,int H, int D) {
  if (scale_ == 1) {
    draw_image_mono_unscaled(cb, data, X,Y,W,H,D);
  } else {
    draw_image_rescale(data, cb, X, Y, W, H, D, 0, true, scale_);
  }
}

void Fl_Scalable_Graphics_Driver::transformed_vertex(double xf, double yf) {
  transformed_vertex0(xf * scale_, yf * scale_);
}

void Fl_Scalable_Graphics_Driver::vertex(double x,double y) {
  transformed_vertex0((x*m.a + y*m.c + m.x) * scale_, (x*m.b + y*m.d + m.y) * scale_);
}

void Fl_Scalable_Graphics_Driver::unscale_clip(Fl_Region r) {
  if (r) {
    if (rstack[rstackptr]) XDestroyRegion(rstack[rstackptr]);
    rstack[rstackptr] = r;
  }
}

#endif // !FL_DOXYGEN

//
// End of "$Id$".
//