image widget

many assumptions about X backed were made, to be refined if does not work properly in some setups
2016-05-24 15:38:44 +02:00
parent 50c00218c7
commit d08a2b1a60
9 changed files with 194 additions and 4 deletions
@@ -0,0 +1,112 @@
+#include "gui.h"
+#include "gui_defs.h"
+#include "x.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <png.h>
+
+static void paint(gui *_gui, widget *_w)
+{
+  struct gui *g = _gui;
+  struct image_widget *w = _w;
+  x_draw_image(g->x, g->xwin, w->x, w->common.x, w->common.y);
+}
+
+static void hints(gui *_gui, widget *_w, int *width, int *height)
+{
+  struct image_widget *w = _w;
+  LOGD("HINTS image %p\n", w);
+  *width = w->width;
+  *height = w->height;
+}
+
+struct png_reader {
+  unsigned char *data;
+  int size;
+  int pos;
+};
+
+static void png_readfn(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+  struct png_reader *r = png_get_io_ptr(png_ptr);
+  if (length > r->size - r->pos) png_error(png_ptr, "bad png image");
+  memcpy(data, r->data + r->pos, length);
+  r->pos += length;
+}
+
+static void load_image(struct gui *g, struct image_widget *w,
+    unsigned char *data, int length)
+{
+  png_structp png_ptr;
+  png_infop info_ptr;
+  png_bytepp image;
+  int width, height, bit_depth, color_type, channels;
+  unsigned char *img_data;
+  struct png_reader r;
+  int i;
+
+  /* unpack PNG data */
+
+  r.data = data;
+  r.size = length;
+  r.pos = 0;
+
+  png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+  if (png_ptr == NULL) abort();
+
+  info_ptr = png_create_info_struct(png_ptr);
+  if (info_ptr == NULL) abort();
+
+  if (setjmp(png_jmpbuf(png_ptr))) abort();
+
+  png_set_read_fn(png_ptr, &r, png_readfn);
+
+  png_read_png(png_ptr, info_ptr,
+      PNG_TRANSFORM_STRIP_16 | PNG_TRANSFORM_EXPAND | PNG_TRANSFORM_PACKING |
+      PNG_TRANSFORM_GRAY_TO_RGB | PNG_TRANSFORM_BGR, NULL);
+
+  image = png_get_rows(png_ptr, info_ptr);
+
+  width = png_get_image_width(png_ptr, info_ptr);
+  height = png_get_image_height(png_ptr, info_ptr);
+  bit_depth = png_get_bit_depth(png_ptr, info_ptr);
+  color_type = png_get_color_type(png_ptr, info_ptr);
+  channels = png_get_channels(png_ptr, info_ptr);
+
+  if (width < 1 || width > 1000 || height < 1 || height > 1000 ||
+      bit_depth != 8 || color_type != PNG_COLOR_TYPE_RGBA || channels != 4)
+    { printf("bad image\n"); abort(); }
+
+  img_data = malloc(4 * width * height); if (img_data == NULL) abort();
+  for (i = 0; i < height; i++)
+    memcpy(img_data+i*4*width, image[i], width*4);
+
+  png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+
+  /* create the X image */
+  w->x = x_create_image(g->x, img_data, width, height);
+
+  free(img_data);
+
+  w->width = width;
+  w->height = height;
+}
+
+widget *new_image(gui *_gui, unsigned char *data, int length)
+{
+  struct gui *g = _gui;
+  struct image_widget *w;
+
+  glock(g);
+
+  w = new_widget(g, IMAGE, sizeof(struct image_widget));
+
+  load_image(g, w, data, length);
+
+  w->common.paint = paint;
+  w->common.hints = hints;
+
+  gunlock(g);
+
+  return w;
+}