Added PNG loadin support through a new Image class.

1 files changed, 160 insertions, 0 deletions

diff --git a/plugingui/image.cc b/plugingui/image.cc
new file mode 100644
index 0000000..1a0e73c
--- /dev/null
+++ b/plugingui/image.cc
@@ -0,0 +1,160 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/***************************************************************************
+ *            image.cc
+ *
+ *  Sat Mar 16 15:05:09 CET 2013
+ *  Copyright 2013 Bent Bisballe Nyeng
+ *  deva@aasimon.org
+ ****************************************************************************/
+
+/*
+ *  This file is part of DrumGizmo.
+ *
+ *  DrumGizmo 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.
+ *
+ *  DrumGizmo 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 DrumGizmo; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
+ */
+#include "image.h"
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdarg.h>
+
+void abort_(const char * s, ...)
+{
+  va_list args;
+  va_start(args, s);
+  vfprintf(stderr, s, args);
+  fprintf(stderr, "\n");
+  va_end(args);
+  abort();
+}
+
+GUI::Image::Image(const char* data, size_t size)
+{
+}
+
+GUI::Image::Image(std::string filename)
+{
+  char header[8];    // 8 is the maximum size that can be checked
+
+  /* open file and test for it being a png */
+  FILE *fp = fopen(filename.c_str(), "rb");
+  if (!fp)
+    abort_("[read_png_file] File %s could not be opened for reading",
+           filename.c_str());
+  size_t r = fread(header, 1, 8, fp);
+  (void)r;
+  if(png_sig_cmp((const png_byte*)header, 0, 8)) {
+    abort_("[read_png_file] File %s is not recognized as a PNG file",
+           filename.c_str());
+  }
+  
+  /* initialize stuff */
+  png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+  
+  if(!png_ptr) {
+    abort_("[read_png_file] png_create_read_struct failed");
+  }
+  
+  info_ptr = png_create_info_struct(png_ptr);
+  if(!info_ptr) {
+    abort_("[read_png_file] png_create_info_struct failed");
+  }
+  
+  if(setjmp(png_jmpbuf(png_ptr))) {
+    abort_("[read_png_file] Error during init_io");
+  }
+  
+  png_init_io(png_ptr, fp);
+  png_set_sig_bytes(png_ptr, 8);
+  
+  png_read_info(png_ptr, info_ptr);
+  
+  w = png_get_image_width(png_ptr, info_ptr);
+  h = png_get_image_height(png_ptr, info_ptr);
+  color_type = png_get_color_type(png_ptr, info_ptr);
+  bit_depth = png_get_bit_depth(png_ptr, info_ptr);
+  
+  number_of_passes = png_set_interlace_handling(png_ptr);
+  png_read_update_info(png_ptr, info_ptr);
+  
+  
+  /* read file */
+  if (setjmp(png_jmpbuf(png_ptr))) {
+    abort_("[read_png_file] Error during read_image");
+  }
+  
+  row_pointers = (png_bytep*) malloc(sizeof(png_bytep) * h);
+  size_t y;
+  for(y = 0; y < h; y++) {
+    row_pointers[y] = (png_byte*) malloc(png_get_rowbytes(png_ptr,info_ptr));
+  }
+  
+  png_read_image(png_ptr, row_pointers);
+  
+  fclose(fp);
+}
+#if 0
+void process_file(void)
+{
+  if(png_get_color_type(png_ptr, info_ptr) == PNG_COLOR_TYPE_RGB) {
+    abort_("[process_file] input file is PNG_COLOR_TYPE_RGB but must be"
+           " PNG_COLOR_TYPE_RGBA (lacks the alpha channel)");
+  }
+
+  if(png_get_color_type(png_ptr, info_ptr) != PNG_COLOR_TYPE_RGBA) {
+    abort_("[process_file] color_type of input file must be "
+           "PNG_COLOR_TYPE_RGBA (%d) (is %d)",
+           PNG_COLOR_TYPE_RGBA, png_get_color_type(png_ptr, info_ptr));
+  }
+
+  size_t x, y; 
+  for(y = 0; y < height(); y++) {
+    png_byte* row = row_pointers[y];
+    for(x = 0; x < width; x++) {
+      png_byte* ptr = &(row[x*4]);
+      printf("Pixel at position [%d - %d] has RGBA values: %d - %d - %d - %d\n",
+             x, y, ptr[0], ptr[1], ptr[2], ptr[3]);
+      
+      /* set red value to 0 and green value to the blue one */
+      ptr[0] = 0;
+      ptr[1] = ptr[2];
+    }
+  }
+}
+#endif
+
+GUI::Image::~Image()
+{
+}
+
+size_t GUI::Image::width()
+{
+  return w;
+}
+
+size_t GUI::Image::height()
+{
+  return h;
+}
+
+GUI::Colour GUI::Image::getPixel(size_t x, size_t y)
+{
+  png_byte* row = row_pointers[y];
+  png_byte* ptr = &(row[x*4]);
+  GUI::Colour c(ptr[0], ptr[1], ptr[2], ptr[3]);
+  return c;
+}