svg: rasterize with output resolution

1 files changed, 47 insertions, 33 deletions

diff --git a/svg.c b/svg.c
index b332b29..b9d5d6e 100644
--- a/svg.c
+++ b/svg.c
@@ -9,47 +9,60 @@
 #include "log.h"
 #include "stride.h"
 
-pixman_image_t *
+struct NSVGimage *svg_image = NULL;
+struct NSVGrasterizer *rast = NULL;
+
+bool
 svg_load(FILE *fp, const char *path)
 {
-    pixman_image_t *pix = NULL;
-    uint8_t *data = NULL;
-    int width, height, stride;
-    bool ok = false;
-    struct NSVGimage *image = NULL;
-    struct NSVGrasterizer *rast = NULL;
-
-    image = nsvgParseFromFile(path, "px", 96);
-    width = image->width;
-    height = image->height;
-    if (width == 0 || height == 0) {
+    svg_image = nsvgParseFromFile(path, "px", 96);
+    if (svg_image == NULL)
+        return false;
+    if (svg_image->width == 0 || svg_image->height == 0) {
         LOG_DBG("%s: width and/or heigth is zero, not a SVG?", path);
-        nsvgDelete(image);
-        return NULL;
+        nsvgDelete(svg_image);
+        svg_image = NULL;
+        return false;
     }
-    stride = stride_for_format_and_width(PIXMAN_a8b8g8r8, image->width);
+    rast = nsvgCreateRasterizer();
+    if (rast == NULL)
+        return false;
+    return true;
+}
+
+pixman_image_t *
+svg_render(const int width, const int height)
+{
+    pixman_image_t *pix = NULL;
+    uint8_t *data = NULL;
+    int stride = stride_for_format_and_width(PIXMAN_a8b8g8r8, width);
 
     if (!(data = calloc(1, height * stride)))
-        goto out;
+        return NULL;
+
+    double sx = width / (double)svg_image->width;
+    double sy = height / (double)svg_image->height;
 
-    if (!(rast = nsvgCreateRasterizer()))
-        goto out;
+    float s = sx > sy ? sy : sx;
 
-    nsvgRasterize(rast, image, 0, 0, 1, data, width, height, stride);
+    float tx = (width - svg_image->width * s) / 2;
+    float ty = (height - svg_image->height * s) / 2;
 
-    ok = NULL != (pix = pixman_image_create_bits_no_clear(
-            PIXMAN_a8b8g8r8, width, height, (uint32_t *)data, stride));
+    nsvgRasterize(rast, svg_image, tx, ty, s, data, width, height, stride);
 
-    if (!ok) {
-        LOG_ERR("%s: failed to instanciate pixman image", path);
-        goto out;
+    pix = pixman_image_create_bits_no_clear(PIXMAN_a8b8g8r8, width,
+        height, (uint32_t *)data, stride);
+    if (pix == NULL) {
+        LOG_ERR("failed to render svg image");
+        free(data);
+        return NULL;
     }
 
     /* Copied from fuzzel */
     /* Nanosvg produces non-premultiplied ABGR, while pixman expects
      * premultiplied */
     for (uint32_t *abgr = (uint32_t *)data;
-         abgr < (uint32_t *)(data + (size_t)image->width * (size_t)image->height * 4);
+         abgr < (uint32_t *)(data + (size_t)width * (size_t)height * 4);
          abgr++) {
         uint8_t alpha = (*abgr >> 24) & 0xff;
         uint8_t blue = (*abgr >> 16) & 0xff;
@@ -70,13 +83,14 @@ svg_load(FILE *fp, const char *path)
         *abgr = (uint32_t)alpha << 24 | blue << 16 | green << 8 | red;
     }
 
-out:
-    if (image)
-        nsvgDelete(image);
-    if (rast)
-        nsvgDeleteRasterizer(rast);
-
-    if (!ok)
-        free(data);
     return pix;
 }
+
+void
+svg_free()
+{
+    if (svg_image != NULL)
+        nsvgDelete(svg_image);
+    if (rast != NULL)
+        nsvgDeleteRasterizer(rast);
+}