Warning for glMap*Buffer* failures.

[apitrace] / image.cpp

diff --git a/image.cpp b/image.cpp
index 937f486bfbc01cbe3676b54ce67be52f84b1a754..922c4d432ae1616f0a4db1b14410adc9f128603a 100644 (file)
--- a/image.cpp
+++ b/image.cpp
@@ -24,10 +24,12 @@
  **************************************************************************/
 
 
+#include <zlib.h>
 #include <png.h>
 
 #include <math.h>
 #include <stdint.h>
+#include <stdlib.h>
 
 #include <fstream>
 
@@ -309,6 +311,115 @@ double Image::compare(Image &ref)
     return precision;
 }
 
+struct png_tmp_buffer
+{
+    char *buffer;
+    size_t size;
+};
+
+static void
+pngWriteCallback(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+    struct png_tmp_buffer *buf = (struct png_tmp_buffer*) png_get_io_ptr(png_ptr);
+    size_t nsize = buf->size + length;
+
+    /* allocate or grow buffer */
+    if (buf->buffer)
+        buf->buffer = (char*)realloc(buf->buffer, nsize);
+    else
+        buf->buffer = (char*)malloc(nsize);
+
+    if (!buf->buffer)
+        png_error(png_ptr, "Buffer allocation error");
+
+    memcpy(buf->buffer + buf->size, data, length);
+    buf->size += length;
+}
+
+bool writePixelsToBuffer(unsigned char *pixels,
+                         unsigned width, unsigned height, unsigned numChannels,
+                         bool flipped,
+                         char **buffer,
+                         int *size)
+{
+    struct png_tmp_buffer png_mem;
+    png_structp png_ptr;
+    png_infop info_ptr;
+    int type;
+
+    png_mem.buffer = NULL;
+    png_mem.size = 0;
+
+    switch (numChannels) {
+    case 4:
+        type = PNG_COLOR_TYPE_RGB_ALPHA;
+        break;
+    case 3:
+        type = PNG_COLOR_TYPE_RGB;
+        break;
+    case 2:
+        type = PNG_COLOR_TYPE_GRAY_ALPHA;
+        break;
+    case 1:
+        type = PNG_COLOR_TYPE_GRAY;
+        break;
+    default:
+        goto no_png;
+    }
+
+    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+    if (!png_ptr)
+        goto no_png;
+
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr) {
+        png_destroy_write_struct(&png_ptr,  NULL);
+        goto no_png;
+    }
+
+    if (setjmp(png_jmpbuf(png_ptr))) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        goto no_png;
+    }
+
+    png_set_write_fn(png_ptr, &png_mem, pngWriteCallback, NULL);
+
+    png_set_IHDR(png_ptr, info_ptr, width, height, 8,
+                 type, PNG_INTERLACE_NONE,
+                 PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+    png_set_compression_level(png_ptr, Z_DEFAULT_COMPRESSION);
+
+    png_write_info(png_ptr, info_ptr);
+
+    if (!flipped) {
+        for (unsigned y = 0; y < height; ++y) {
+            png_bytep row = (png_bytep)(pixels + y*width*numChannels);
+            png_write_rows(png_ptr, &row, 1);
+        }
+    } else {
+        unsigned y = height;
+        while (y--) {
+            png_bytep row = (png_bytep)(pixels + y*width*numChannels);
+            png_write_rows(png_ptr, &row, 1);
+        }
+    }
+
+    png_write_end(png_ptr, info_ptr);
+    png_destroy_write_struct(&png_ptr, &info_ptr);
 
+    *buffer = png_mem.buffer;
+    *size = png_mem.size;
+
+    return true;
+
+no_png:
+    *buffer = NULL;
+    *size = 0;
+
+    if (png_mem.buffer)
+        free(png_mem.buffer);
+    return false;
+}
 
 } /* namespace Image */