X-Git-Url: https://git.cworth.org/git?a=blobdiff_plain;f=image.cpp;h=937f486bfbc01cbe3676b54ce67be52f84b1a754;hb=67dfb223601baf074c3ae422dbc5cc070e70c034;hp=ec056d738d8c0b417c159842aa68b5d2717e7167;hpb=20f35e03712f58ec4dd51508f3874b3685738aa9;p=apitrace

diff --git a/image.cpp b/image.cpp
index ec056d7..937f486 100644
--- a/image.cpp
+++ b/image.cpp
@@ -24,6 +24,9 @@
  **************************************************************************/
 
 
+#include <png.h>
+
+#include <math.h>
 #include <stdint.h>
 
 #include <fstream>
@@ -66,7 +69,7 @@ struct Pixel {
 };
 
 
-void
+bool
 Image::writeBMP(const char *filename) const {
     struct FileHeader bmfh;
     struct InfoHeader bmih;
@@ -92,6 +95,9 @@ Image::writeBMP(const char *filename) const {
 
     std::ofstream stream(filename, std::ofstream::binary);
 
+    if (!stream)
+        return false;
+
     stream.write((const char *)&bmfh, 14);
     stream.write((const char *)&bmih, 40);
 
@@ -125,7 +131,184 @@ Image::writeBMP(const char *filename) const {
     }
 
     stream.close();
+
+    return true;
+}
+
+bool
+Image::writePNG(const char *filename) const {
+    FILE *fp;
+    png_structp png_ptr;
+    png_infop info_ptr;
+
+    fp = fopen(filename, "wb");
+    if (!fp)
+        goto no_fp;
+
+    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_init_io(png_ptr, fp);
+
+    png_set_IHDR(png_ptr, info_ptr, width, height, 8, PNG_COLOR_TYPE_RGB_ALPHA,
+        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*4);
+            png_write_rows(png_ptr, &row, 1);
+        }
+    } else {
+        unsigned y = height;
+        while (y--) {
+            png_bytep row = (png_bytep)(pixels + y*width*4);
+            png_write_rows(png_ptr, &row, 1);
+        }
+    }
+
+    png_write_end(png_ptr, info_ptr);
+    png_destroy_write_struct(&png_ptr, &info_ptr);
+
+    fclose(fp);
+    return true;
+
+no_png:
+    fclose(fp);
+no_fp:
+    return false;
 }
 
 
+Image *
+readPNG(const char *filename)
+{
+    FILE *fp;
+    png_structp png_ptr;
+    png_infop info_ptr;
+    png_infop end_info;
+    Image *image;
+
+    fp = fopen(filename, "rb");
+    if (!fp)
+        goto no_fp;
+
+    png_ptr = png_create_read_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_read_struct(&png_ptr, NULL, NULL);
+        goto no_png;
+    }
+
+    end_info = png_create_info_struct(png_ptr);
+    if (!end_info) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        goto no_png;
+    }
+
+    if (setjmp(png_jmpbuf(png_ptr))) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
+        goto no_png;
+    }
+
+    png_init_io(png_ptr, fp);
+
+    png_read_info(png_ptr, info_ptr);
+
+    png_uint_32 width, height;
+    int bit_depth, color_type, interlace_type, compression_type, filter_method;
+
+    png_get_IHDR(png_ptr, info_ptr,
+                 &width, &height,
+                 &bit_depth, &color_type, &interlace_type,
+                 &compression_type, &filter_method);
+
+    image = new Image(width, height);
+    if (!image)
+        goto no_image;
+
+    /* Convert to RGBA8 */
+    if (color_type == PNG_COLOR_TYPE_PALETTE)
+        png_set_palette_to_rgb(png_ptr);
+    if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
+        png_set_expand_gray_1_2_4_to_8(png_ptr);
+    if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+        png_set_tRNS_to_alpha(png_ptr);
+    if (bit_depth == 16)
+        png_set_strip_16(png_ptr);
+
+    for (unsigned y = 0; y < height; ++y) {
+        png_bytep row = (png_bytep)(image->pixels + y*width*4);
+        png_read_row(png_ptr, row, NULL);
+    }
+
+    png_read_end(png_ptr, info_ptr);
+    png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
+    fclose(fp);
+    return image;
+
+no_image:
+    png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
+no_png:
+    fclose(fp);
+no_fp:
+    return NULL;
+}
+
+
+double Image::compare(Image &ref)
+{
+    if (width != ref.width ||
+        height != ref.height) {
+        return 0.0;
+    }
+
+    const unsigned char *pSrc = start();
+    const unsigned char *pRef = ref.start();
+
+    unsigned long long error = 0;
+    for (unsigned y = 0; y < height; ++y) {
+        for (unsigned  x = 0; x < width; ++x) {
+            // FIXME: Ignore alpha channel until we are able to pick a visual
+            // that matches the traces
+            for (unsigned  c = 0; c < 3; ++c) {
+                int delta = pSrc[x*4 + c] - pRef[x*4 + c];
+                error += delta*delta;
+            }
+        }
+
+        pSrc += stride();
+        pRef += ref.stride();
+    }
+
+    double numerator = error*2 + 1;
+    double denominator = height*width*3ULL*255ULL*255ULL*2;
+    double quotient = numerator/denominator;
+
+    // Precision in bits
+    double precision = -log(quotient)/log(2.0);
+
+    return precision;
+}
+
+
+
 } /* namespace Image */