UI: Allow RGB to be used with image array passed to IMAGE

Author: chrisws

ChangeLog

@@ -1,3 +1,6 @@
+2021-07-28 (12.22)
+	UI: Allow RGB to be used with image array passed to IMAGE
+
 2021-07-27 (12.22)
 	FLTK: Fix PSET display of extra pixel
 

src/platform/console/image.cpp

@@ -127,7 +127,7 @@ ImageBuffer *load_image(var_t *var) {
       for (int x = 0; x < w; x++) {
         int pos = y * w + x;
         uint8_t a, r, g, b;
-        v_get_argb(-v_getint(v_elem(var, pos)), a, r, g, b);
+        v_get_argb(v_getint(v_elem(var, pos)), a, r, g, b);
         SET_IMAGE_ARGB(image, yoffs + (x * 4), a, r, g, b);
       }
     }
@@ -492,3 +492,4 @@ extern "C" void v_create_image(var_p_t var) {
     err_throw(ERR_BAD_FILE_HANDLE);
   }
 }
+

src/ui/rgb.h

@@ -17,11 +17,24 @@ typedef uint32_t pixel_t;
 #define PIXELFORMAT AHARDWAREBUFFER_FORMAT_R8G8B8X8_UNORM
 #endif
 
-inline void v_get_argb(pixel_t c, uint8_t &a, uint8_t &r, uint8_t &g, uint8_t &b) {
-  a = (c & 0xff000000) >> 24;
-  r = (c & 0xff0000) >> 16;
-  g = (c & 0xff00) >> 8;
-  b = (c & 0xff);
+inline void v_get_argb(int64_t c, uint8_t &a, uint8_t &r, uint8_t &g, uint8_t &b) {
+  if (c == 0) {
+    a = 0;
+    r = 0;
+    g = 0;
+    b = 0;
+  } if (c < 0) {
+    // from RGB
+    a = 255;
+    r = (-c & 0xff0000) >> 16;
+    g = (-c & 0xff00) >> 8;
+    b = (-c & 0xff);
+  } else {
+    a = (c & 0xff000000) >> 24;
+    r = (c & 0xff0000) >> 16;
+    g = (c & 0xff00) >> 8;
+    b = (c & 0xff);
+  }
 }
 
 #define v_get_argb_px(a, r, g, b) (a << 24 | (r << 16) | (g << 8) | (b))