Merge branch 'jpeg'

lib/image.js

@@ -21,6 +21,7 @@ var Canvas = require('../build/default/canvas')
 
 Image.prototype.inspect = function(){
   return '[Image'
+    + (this.complete ? ':' + this.width + 'x' + this.height : '')
     + (this.src ? ' ' + this.src : '')
     + (this.complete ? ' complete' : '')
     + ']';

src/Image.cc

@@ -9,6 +9,7 @@
 #include "Image.h"
 #include <stdlib.h>
 #include <string.h>
+#include <jpeglib.h>
 
 Persistent<FunctionTemplate> Image::constructor;
 
@@ -264,13 +265,90 @@ Image::error(Local<Value> err) {
 /*
  * Load cairo surface from the image src.
  * 
+ * TODO: better format detection
  * TODO: support more formats
  */
 
 cairo_status_t
 Image::loadSurface() {
+  switch (extension(filename)) {
+    case Image::PNG: return loadPNG();
+    case Image::JPEG: return loadJPEG();
+  }
+  return CAIRO_STATUS_READ_ERROR;
+}
+
+/*
+ * Load PNG.
+ */
+
+cairo_status_t
+Image::loadPNG() {
   _surface = cairo_image_surface_create_from_png(filename);
   width = cairo_image_surface_get_width(_surface);
   height = cairo_image_surface_get_height(_surface);
   return cairo_surface_status(_surface);
 }
+
+/*
+ * Load JPEG, convert RGB to ARGB.
+ */
+
+cairo_status_t
+Image::loadJPEG() {
+  // TODO: error handling
+  // TODO: move to node IO
+  FILE *stream = fopen(filename, "r");
+  struct jpeg_decompress_struct info;
+  struct jpeg_error_mgr err;
+  info.err = jpeg_std_error(&err);
+  jpeg_create_decompress(&info);
+  jpeg_stdio_src(&info, stream);
+  jpeg_read_header(&info, 1);
+  jpeg_start_decompress(&info);
+  width = info.output_width;
+  height = info.output_height;
+
+  int stride = width * 4;
+  uint8_t *data = (uint8_t *) malloc(width * height * 4);
+  uint8_t *src = (uint8_t *) malloc(width * 3);
+
+  for (int y = 0; y < height; ++y) {
+    jpeg_read_scanlines(&info, &src, 1);
+    uint32_t *row = (uint32_t *)(data + stride * y);
+    for (int x = 0; x < width; ++x) {
+      int bx = 3 * x;
+      uint32_t *pixel = row + x;
+      *pixel = 255 << 24
+        | src[bx + 0] << 16
+        | src[bx + 1] << 8
+        | src[bx + 2];
+    }
+  }
+
+  _surface = cairo_image_surface_create_for_data(
+      data
+    , CAIRO_FORMAT_ARGB32
+    , width
+    , height
+    , width * 4);
+
+  fclose(stream);
+  jpeg_finish_decompress(&info);
+  jpeg_destroy_decompress(&info);
+  return cairo_surface_status(_surface);
+}
+
+/*
+ * Return UNKNOWN, JPEG, or PNG based on the filename.
+ */
+
+Image::type
+Image::extension(const char *filename) {
+  size_t len = strlen(filename);
+  filename += len;
+  if (0 == strcmp(".jpeg", filename - 5)) return Image::JPEG;
+  if (0 == strcmp(".jpg", filename - 4)) return Image::JPEG;
+  if (0 == strcmp(".png", filename - 4)) return Image::PNG;
+  return Image::UNKNOWN;
+}

src/Image.h

@@ -32,6 +32,8 @@ class Image: public node::ObjectWrap {
     inline uint8_t *data(){ return cairo_image_surface_get_data(_surface); } 
     inline int stride(){ return cairo_image_surface_get_stride(_surface); } 
     cairo_status_t loadSurface();
+    cairo_status_t loadPNG();
+    cairo_status_t loadJPEG();
     void error(Local<Value>);
     void loadSync();
     void loaded();
@@ -44,6 +46,14 @@ class Image: public node::ObjectWrap {
       , COMPLETE
     } state;
 
+    typedef enum {
+        UNKNOWN
+      , JPEG
+      , PNG
+    } type;
+
+    static type extension(const char *filename);
+  
   private:
     cairo_surface_t *_surface;
     ~Image();

wscript

@@ -11,6 +11,7 @@ def configure(conf):
   conf.check_tool('compiler_cxx')
   conf.check_tool('node_addon')
   conf.env.append_value('CPPFLAGS', '-DNDEBUG')
+  conf.check(lib='jpeg', uselib_store='JPEG')
   conf.check_cfg(package='cairo', mandatory=1, args='--cflags --libs')
   flags = ['-O3', '-Wall']
   conf.env.append_value('CCFLAGS', flags)
@@ -20,4 +21,4 @@ def build(bld):
   obj = bld.new_task_gen('cxx', 'shlib', 'node_addon')
   obj.target = 'canvas'
   obj.source = bld.glob('src/*.cc')
-  obj.uselib = ['CAIRO']
+  obj.uselib = ['CAIRO', 'JPEG']