ncblit_bgrx() improvements #1105

Add unit tests for ncblit_bgrx. Rewrite bgra_to_rgba() using
ncpixel_*() funtionality. Rewrite ncblit_bgrx() using
ncblit_rgba().

src/lib/blit.c

@@ -830,50 +830,21 @@ const char* notcurses_str_blitter(ncblitter_e blitter){
 }
 
 int ncblit_bgrx(const void* data, int linesize, const struct ncvisual_options* vopts){
-  if(vopts->flags > NCVISUAL_OPTION_BLEND){
-    return -1;
-  }
-  if(linesize <= 0 || (size_t)linesize < vopts->lenx * sizeof(uint32_t)){
-    return -1;
-  }
-  struct ncplane* nc = vopts->n;
-  if(nc == NULL){
+  if(vopts->leny <= 0 || vopts->lenx <= 0){
     return -1;
   }
-  int lenx = vopts->lenx;
-  int leny = vopts->leny;
-  int begy = vopts->begy;
-  int begx = vopts->begx;
-//fprintf(stderr, "render %dx%d+%dx%d %p\n", begy, begx, leny, lenx, ncv->data);
-  if(begy < 0 || begx < 0 || lenx < -1 || leny < -1){
-    return -1;
-  }
-  ncblitter_e blitter;
-  if(!vopts || vopts->blitter == NCBLIT_DEFAULT){
-    blitter = ncvisual_default_blitter(nc, NCSCALE_NONE);
-  }else{
-    blitter = vopts->blitter;
-  }
-  const bool degrade = !(vopts->flags & NCVISUAL_OPTION_NODEGRADE);
-  const struct blitset* bset = lookup_blitset(notcurses_canutf8(nc->nc),
-                                              blitter, degrade);
-  if(bset == NULL){
-    return -1;
-  }
-  const bool blend = (vopts->flags & NCVISUAL_OPTION_BLEND);
-  void* rdata = bgra_to_rgba(data, leny, linesize, lenx);
+  void* rdata = bgra_to_rgba(data, vopts->leny, linesize, vopts->lenx);
   if(rdata == NULL){
     return -1;
   }
-  int r = bset->blit(nc, vopts->y, vopts->x, linesize, rdata, begy, begx,
-                     leny, lenx, blend);
+  int r = ncblit_rgba(rdata, linesize, vopts);
   free(rdata);
   return r;
 }
 
 int ncblit_rgba(const void* data, int linesize, const struct ncvisual_options* vopts){
   if(vopts->flags > NCVISUAL_OPTION_BLEND){
-    return -1;
+    fprintf(stderr, "Warning: unknown ncvisual options %016lx\n", vopts->flags);
   }
   if(linesize <= 0 || (size_t)linesize < vopts->lenx * sizeof(uint32_t)){
     return -1;

src/lib/visual.cpp

@@ -65,8 +65,10 @@ auto bgra_to_rgba(const void* data, int rows, int rowstride, int cols) -> void*
       for(int x = 0 ; x < cols ; ++x){
         const uint32_t* src = (const uint32_t*)data + (rowstride / 4) * y + x;
         uint32_t* dst = ret + (rowstride / 4) * y + x;
-        *dst = ((*src & 0xff00u) << 16u) | (*src & 0xff00ffu) | ((*src & 0xff000000) >> 16u);
-//fprintf(stderr, "y: %d x: %d SRC: %x DST: %x\n", y, x, *src, *dst);
+        ncpixel_set_a(dst, 0xff);
+        ncpixel_set_r(dst, ncpixel_b(*src));
+        ncpixel_set_g(dst, ncpixel_g(*src));
+        ncpixel_set_b(dst, ncpixel_r(*src));
       }
     }
   }
@@ -362,7 +364,7 @@ auto ncvisual_from_bgra(const void* bgra, int rows, int rowstride,
 auto ncvisual_render(notcurses* nc, ncvisual* ncv,
                      const struct ncvisual_options* vopts) -> ncplane* {
   if(vopts && vopts->flags > NCVISUAL_OPTION_BLEND){
-    return nullptr;
+    fprintf(stderr, "Warning: unknown ncvisual options %016lx\n", vopts->flags);
   }
   int lenx = vopts ? vopts->lenx : 0;
   int leny = vopts ? vopts->leny : 0;

tests/blit.cpp

@@ -0,0 +1,89 @@
+#include "main.h"
+#include <vector>
+
+TEST_CASE("Blitting") {
+  auto nc_ = testing_notcurses();
+  REQUIRE(nullptr != nc_);
+  ncplane* ncp_ = notcurses_stdplane(nc_);
+  REQUIRE(ncp_);
+  auto n_ = notcurses_stdplane(nc_);
+  REQUIRE(n_);
+
+  SUBCASE("BgraToRgba") {
+    const uint32_t data[8] = {
+      0xffffffff, 0xff0088ff, 0xffff8800, 0xff88ff00,
+      0xffff0088, 0xff8800ff, 0Xff00ff88, 0xff000000,
+    };
+    auto ncp = ncplane_new(n_, 2, 4, 0, 0, nullptr, nullptr);
+    REQUIRE(nullptr != ncp);
+    struct ncvisual_options vopts = {
+      .n = ncp,
+      .scaling = NCSCALE_NONE,
+      .y = 0,
+      .x = 0,
+      .begy = 0,
+      .begx = 0,
+      .leny = 2,
+      .lenx = 4,
+      .blitter = NCBLIT_1x1,
+      .flags = 0,
+    };
+    ncblit_bgrx(data, 16, &vopts);
+    for(int y = 0 ; y < 2 ; ++y){
+      for(int x = 0 ; x < 4 ; ++x){
+        uint32_t bgra = data[(y * 4) + x];
+        uint16_t stylemask;
+        uint64_t channels;
+        auto egc = ncplane_at_yx(ncp, y, x, &stylemask, &channels);
+        CHECK(0 == strcmp(" ", egc));
+        free(egc);
+        CHECK(0 == stylemask);
+        uint32_t rgb = channels_bg_rgb(channels);
+        CHECK(ncpixel_r(bgra) == ncpixel_r(rgb));
+        CHECK(ncpixel_g(bgra) == ncpixel_g(rgb));
+        CHECK(ncpixel_b(bgra) == ncpixel_b(rgb));
+      }
+    }
+    ncplane_destroy(ncp);
+  }
+
+  SUBCASE("BgraToRgbaWithStride") {
+    const uint32_t data[10] = {
+      0xffffffff, 0xff0088ff, 0xffff8800, 0xff88ff00, 0x00000000,
+      0xffff0088, 0xff8800ff, 0xff00ff88, 0xff000000, 0x00000000,
+    };
+    auto ncp = ncplane_new(n_, 2, 4, 0, 0, nullptr, nullptr);
+    REQUIRE(nullptr != ncp);
+    struct ncvisual_options vopts = {
+      .n = ncp,
+      .scaling = NCSCALE_NONE,
+      .y = 0,
+      .x = 0,
+      .begy = 0,
+      .begx = 0,
+      .leny = 2,
+      .lenx = 4,
+      .blitter = NCBLIT_1x1,
+      .flags = 0,
+    };
+    ncblit_bgrx(data, 20, &vopts);
+    for(int y = 0 ; y < 2 ; ++y){
+      for(int x = 0 ; x < 4 ; ++x){
+        uint32_t bgra = data[(y * 5) + x];
+        uint16_t stylemask;
+        uint64_t channels;
+        auto egc = ncplane_at_yx(ncp, y, x, &stylemask, &channels);
+        CHECK(0 == strcmp(" ", egc));
+        free(egc);
+        CHECK(0 == stylemask);
+        uint32_t rgb = channels_bg_rgb(channels);
+        CHECK(ncpixel_r(bgra) == ncpixel_r(rgb));
+        CHECK(ncpixel_g(bgra) == ncpixel_g(rgb));
+        CHECK(ncpixel_b(bgra) == ncpixel_b(rgb));
+      }
+    }
+    ncplane_destroy(ncp);
+  }
+
+  CHECK(!notcurses_stop(nc_));
+}