implement ncvisual_inflate(), add unit test #1546

src/lib/visual.c

@@ -899,3 +899,40 @@ int ncvisual_resize(ncvisual* nc, int rows, int cols){
   }
   return visual_implementation->visual_resize(nc, rows, cols);
 }
+
+// Inflate each pixel of 'bmap' to 'scale'x'scale' pixels square, using the
+// same color as the original pixel.
+static inline void*
+inflate_bitmap(const uint32_t* bmap, int scale, int rows, int stride, int cols){
+  size_t size = rows * cols * scale * scale * sizeof(*bmap);
+  uint32_t* ret = malloc(size);
+  if(ret){
+    for(int y = 0 ; y < rows ; ++y){
+      const uint32_t* src = bmap + y * (stride / sizeof(*bmap));
+      for(int yi = 0 ; yi < scale ; ++yi){
+        uint32_t* dst = ret + (y * scale + yi) * cols * scale;
+        for(int x = 0 ; x < cols ; ++x){
+          for(int xi = 0 ; xi < scale ; ++xi){
+            dst[x * scale + xi] = src[x];
+          }
+        }
+      }
+    }
+  }
+  return ret;
+}
+
+int ncvisual_inflate(ncvisual* n, int scale){
+  if(scale <= 0){
+    return -1;
+  }
+  void* inflaton = inflate_bitmap(n->data, scale, n->rows, n->rowstride, n->cols);
+  if(inflaton == NULL){
+    return -1;
+  }
+  n->rows *= scale;
+  n->cols *= scale;
+  n->rowstride = 4 * n->cols;
+  ncvisual_set_data(n, inflaton, true);
+  return 0;
+}

src/tests/visual.cpp

@@ -1,4 +1,5 @@
 #include "main.h"
+#include "visual-details.h"
 #include <vector>
 
 TEST_CASE("Visual") {
@@ -34,6 +35,33 @@ TEST_CASE("Visual") {
     ncplane_destroy(n);
   }
 
+  SUBCASE("InflateBitmap") {
+    const uint32_t pixels[4] = { htole(0xffff0000), htole(0xff00ff00), htole(0xff0000ff), htole(0xffffffff) };
+    auto ncv = ncvisual_from_rgba(pixels, 2, 8, 2);
+    REQUIRE(ncv);
+    CHECK(0 == ncvisual_inflate(ncv, 3));
+    CHECK(0 == notcurses_render(nc_));
+    CHECK(6 == ncv->rows);
+    CHECK(6 == ncv->cols);
+    for(int y = 0 ; y < 3 ; ++y){
+      for(int x = 0 ; x < 3 ; ++x){
+        CHECK(pixels[0] == ncv->data[y * ncv->cols + x]);
+      }
+      for(int x = 3 ; x < 6 ; ++x){
+        CHECK(pixels[1] == ncv->data[y * ncv->cols + x]);
+      }
+    }
+    for(int y = 3 ; y < 6 ; ++y){
+      for(int x = 0 ; x < 3 ; ++x){
+        CHECK(pixels[2] == ncv->data[y * ncv->cols + x]);
+      }
+      for(int x = 3 ; x < 6 ; ++x){
+        CHECK(pixels[3] == ncv->data[y * ncv->cols + x]);
+      }
+    }
+    ncvisual_destroy(ncv);
+  }
+
   SUBCASE("LoadRGBAFromMemory") {
     int dimy, dimx;
     ncplane_dim_yx(ncp_, &dimy, &dimx);