From 59bf168e55d1a8d2be79f0c73ea0f324e385dfe5 Mon Sep 17 00:00:00 2001
From: nick black <dankamongmen@gmail.com>
Date: Sun, 14 Jun 2020 05:11:11 -0400
Subject: [PATCH] =?UTF-8?q?quadblitter:=20emit=20=E2=96=8C,=20not=20?=
 =?UTF-8?q?=E2=96=8B,=20you=20fool=20#667?=
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---
 src/lib/blit.c   |  2 +-
 tests/visual.cpp | 72 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 73 insertions(+), 1 deletion(-)

diff --git a/src/lib/blit.c b/src/lib/blit.c
index 9acb502a9..4423f1d34 100644
--- a/src/lib/blit.c
+++ b/src/lib/blit.c
@@ -183,7 +183,7 @@ static const struct qdriver {
   const char* oth1egc; // EGC upon absorbing others[1]
 } quadrant_drivers[6] = {
   { .pair = { 0, 1 }, .others = { 2, 3 }, .egc = "▀", .oth0egc = "▛", .oth1egc = "▜", },
-  { .pair = { 0, 2 }, .others = { 1, 3 }, .egc = "▋", .oth0egc = "▛", .oth1egc = "▙", },
+  { .pair = { 0, 2 }, .others = { 1, 3 }, .egc = "▌", .oth0egc = "▛", .oth1egc = "▙", },
   { .pair = { 0, 3 }, .others = { 1, 2 }, .egc = "▚", .oth0egc = "▜", .oth1egc = "▙", },
   { .pair = { 1, 2 }, .others = { 0, 3 }, .egc = "▞", .oth0egc = "▛", .oth1egc = "▟", },
   { .pair = { 1, 3 }, .others = { 0, 2 }, .egc = "▐", .oth0egc = "▜", .oth1egc = "▟", },
diff --git a/tests/visual.cpp b/tests/visual.cpp
index 4ae94bcd6..5c0779c83 100644
--- a/tests/visual.cpp
+++ b/tests/visual.cpp
@@ -241,5 +241,77 @@ TEST_CASE("Visual") {
     delete[] rgba;
   }
 
+  // close-in verification of each quadblitter output EGC 
+  SUBCASE("QuadblitterEGCs") {
+    // there are 16 configurations, each mapping four (2x2) pixels
+    int DIMX = 32;
+    int DIMY = 2;
+    auto rgba = new uint32_t[DIMY * DIMX];
+    memset(rgba, 0, sizeof(*rgba) * DIMY * DIMX);
+    // the top has 4 configurations of 4 each, each being 2 columns
+    for(int top = 0 ; top < 4 ; ++top){
+      for(int idx = 0 ; idx < 4 ; ++idx){
+        const int itop = (top * 4 + idx) * 2; // index of first column
+        CHECK(0 == ncpixel_set_a(&rgba[itop], 0xff));
+        CHECK(0 == ncpixel_set_a(&rgba[itop + 1], 0xff));
+        if(top == 1 || top == 3){
+          CHECK(0 == ncpixel_set_r(&rgba[itop], 0xff));
+        }
+        if(top == 2 || top == 3){
+          CHECK(0 == ncpixel_set_r(&rgba[itop + 1], 0xff));
+        }
+      }
+    }
+    for(int bot = 0 ; bot < 4 ; ++bot){
+      for(int idx = 0 ; idx < 4 ; ++idx){
+        const int ibot = (bot * 4 + idx) * 2 + DIMX;
+        CHECK(0 == ncpixel_set_a(&rgba[ibot], 0xff));
+        CHECK(0 == ncpixel_set_a(&rgba[ibot + 1], 0xff));
+        if(idx == 1 || idx == 3){
+          CHECK(0 == ncpixel_set_r(&rgba[ibot], 0xff));
+        }
+        if(idx == 2 || idx == 3){
+          CHECK(0 == ncpixel_set_r(&rgba[ibot + 1], 0xff));
+        }
+      }
+    }
+    auto ncv = ncvisual_from_rgba(rgba, DIMY, DIMX * sizeof(uint32_t), DIMX);
+    REQUIRE(nullptr != ncv);
+    struct ncvisual_options vopts{};
+    vopts.n = n_;
+    vopts.blitter = NCBLIT_2x2;
+    vopts.flags = NCVISUAL_OPTION_NODEGRADE;
+    CHECK(n_ == ncvisual_render(nc_, ncv, &vopts));
+    CHECK(0 == notcurses_render(nc_));
+    for(int y = 0 ; y < DIMY / 2 ; ++y){
+      for(int x = 0 ; x < DIMX / 2 ; ++x){
+        uint32_t attrword;
+        uint64_t channels;
+        char* egc = notcurses_at_yx(nc_, y, x, &attrword, &channels);
+        REQUIRE(nullptr != egc);
+/* FIXME need to match
+ [▀] 00000000 00000000
+ [▜] 00000000 00ff0000
+ [▛] 00000000 00ff0000
+ [▀] 00000000 00ff0000
+ [▟] 00000000 00ff0000
+ [▋] 00ff0000 00000000
+ [▚] 00ff0000 00000000
+ [▙] 00ff0000 00000000
+ [▙] 00000000 00ff0000
+ [▚] 00000000 00ff0000
+ [▋] 00000000 00ff0000
+ [▟] 00ff0000 00000000
+ [▀] 00ff0000 00000000
+ [▛] 00ff0000 00000000
+ [▜] 00ff0000 00000000
+ [▀] 00ff0000 00ff0000
+ */
+        free(egc);
+      }
+    }
+    delete[] rgba;
+  }
+
   CHECK(!notcurses_stop(nc_));
 }