7 files changed, 783 insertions, 534 deletions

diff --git a/minui/Android.mk b/minui/Android.mk
index cb56b739a..ddec62bf9 100644
--- a/minui/Android.mk
+++ b/minui/Android.mk
@@ -13,6 +13,9 @@
 # limitations under the License.
 
 LOCAL_PATH := $(call my-dir)
+
+# libminui (static library)
+# ===============================
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES := \
@@ -33,13 +36,13 @@ ifeq ($(TW_TARGET_USES_QCOM_BSP), true)
     LOCAL_C_INCLUDES += $(TARGET_OUT_INTERMEDIATES)/KERNEL_OBJ/usr/include
   else
     ifeq ($(TARGET_CUSTOM_KERNEL_HEADERS),)
-      LOCAL_C_INCLUDES += $(commands_recovery_local_path)/minui/include
+      LOCAL_C_INCLUDES += $(LOCAL_PATH)/include
     else
       LOCAL_C_INCLUDES += $(TARGET_CUSTOM_KERNEL_HEADERS)
     endif
   endif
 else
-  LOCAL_C_INCLUDES += $(commands_recovery_local_path)/minui/include
+  LOCAL_C_INCLUDES += $(LOCAL_PATH)/include
   # The header files required for adf graphics can cause compile errors
   # with adf graphics.
   LOCAL_SRC_FILES += graphics_adf.cpp
@@ -50,7 +53,7 @@ ifeq ($(TW_NEW_ION_HEAP), true)
   LOCAL_CFLAGS += -DNEW_ION_HEAP
 endif
 
-LOCAL_STATIC_LIBRARIES += libpng
+LOCAL_STATIC_LIBRARIES += libpng libbase
 ifneq ($(wildcard external/libdrm/Android.common.mk),)
 LOCAL_WHOLE_STATIC_LIBRARIES += libdrm_platform
 else
@@ -61,11 +64,7 @@ ifeq ($(shell test $(PLATFORM_SDK_VERSION) -ge 26; echo $$?),0)
     LOCAL_WHOLE_STATIC_LIBRARIES += libsync_recovery
 endif
 
-LOCAL_STATIC_LIBRARIES := \
-    libpng \
-    libbase
-
-LOCAL_CFLAGS += -Werror -std=c++14
+LOCAL_CFLAGS += -Wall -Werror -std=c++14 -Wno-unused-private-field
 LOCAL_C_INCLUDES += $(LOCAL_PATH)/include
 LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
 
@@ -114,8 +113,16 @@ ifeq ($(wildcard system/core/healthd/animation.h),)
     TARGET_GLOBAL_CFLAGS += -DTW_NO_MINUI_CUSTOM_FONTS
     CLANG_TARGET_GLOBAL_CFLAGS += -DTW_NO_MINUI_CUSTOM_FONTS
 endif
+ifneq ($(TARGET_RECOVERY_DEFAULT_ROTATION),)
+  LOCAL_CFLAGS += -DDEFAULT_ROTATION=$(TARGET_RECOVERY_DEFAULT_ROTATION)
+else
+  LOCAL_CFLAGS += -DDEFAULT_ROTATION=ROTATION_NONE
+endif
+
 include $(BUILD_STATIC_LIBRARY)
 
+# libminui (shared library)
+# ===============================
 # Used by OEMs for factory test images.
 include $(CLEAR_VARS)
 LOCAL_CLANG := true
@@ -125,8 +132,7 @@ LOCAL_SHARED_LIBRARIES := \
     libpng \
     libbase
 
-LOCAL_CFLAGS := -Werror
-
+LOCAL_CFLAGS := -Wall -Werror -std=c++14 -Wno-unused-private-field
 LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
 LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
 include $(BUILD_SHARED_LIBRARY)
diff --git a/minui/events.cpp b/minui/events.cpp
index e9383ca8a..f67684b8b 100644
--- a/minui/events.cpp
+++ b/minui/events.cpp
@@ -15,6 +15,7 @@
  */
 
 #include <dirent.h>
+#include <errno.h>
 #include <fcntl.h>
 #include <linux/input.h>
 #include <stdio.h>
diff --git a/minui/graphics.cpp b/minui/graphics.cpp
index b45e22e06..f3380aaa0 100644
--- a/minui/graphics.cpp
+++ b/minui/graphics.cpp
@@ -16,6 +16,7 @@
 
 #include "graphics.h"
 
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -43,20 +44,26 @@ static int overscan_percent = OVERSCAN_PERCENT;
 static int overscan_offset_x = 0;
 static int overscan_offset_y = 0;
 
+#ifdef TW_NO_MINUI_CUSTOM_FONTS
 static unsigned char gr_current_r = 255;
 static unsigned char gr_current_g = 255;
 static unsigned char gr_current_b = 255;
+#endif
 static unsigned char gr_current_a = 255;
 static unsigned char rgb_555[2];
 static unsigned char gr_current_r5 = 31;
 static unsigned char gr_current_g5 = 63;
 static unsigned char gr_current_b5 = 31;
 
+static uint32_t gr_current = ~0;
+static constexpr uint32_t alpha_mask = 0xff000000;
+
 static GRSurface* gr_draw = NULL;
+static GRRotation rotation = ROTATION_NONE;
 
-static bool outside(int x, int y)
-{
-    return x < 0 || x >= gr_draw->width || y < 0 || y >= gr_draw->height;
+static bool outside(int x, int y) {
+  return x < 0 || x >= (rotation % 2 ? gr_draw->height : gr_draw->width) || y < 0 ||
+         y >= (rotation % 2 ? gr_draw->width : gr_draw->height);
 }
 
 #ifdef TW_NO_MINUI_CUSTOM_FONTS
@@ -71,20 +78,17 @@ void gr_font_size(int *x, int *y)
     *y = gr_font->char_height;
 }
 #else // TW_USE_MINUI_CUSTOM_FONTS
-const GRFont* gr_sys_font()
-{
-    return gr_font;
+const GRFont* gr_sys_font() {
+  return gr_font;
 }
 
-int gr_measure(const GRFont* font, const char *s)
-{
-    return font->char_width * strlen(s);
+int gr_measure(const GRFont* font, const char* s) {
+  return font->char_width * strlen(s);
 }
 
-void gr_font_size(const GRFont* font, int *x, int *y)
-{
-    *x = font->char_width;
-    *y = font->char_height;
+void gr_font_size(const GRFont* font, int* x, int* y) {
+  *x = font->char_width;
+  *y = font->char_height;
 }
 #endif // TW_NO_MINUI_CUSTOM_FONTS
 
@@ -112,7 +116,8 @@ void blend_16bpp(unsigned char* px, unsigned r5, unsigned g5, unsigned b5, unsig
     *px++ = (newred << 3) + (newgreen >> 3);
 }
 
-static void text_blend(unsigned char* src_p, int src_row_bytes,
+#ifdef TW_NO_MINUI_CUSTOM_FONTS
+static void text_blend_old(unsigned char* src_p, int src_row_bytes,
                        unsigned char* dst_p, int dst_row_bytes,
                        int width, int height)
 {
@@ -153,6 +158,154 @@ static void text_blend(unsigned char* src_p, int src_row_bytes,
         dst_p += dst_row_bytes;
     }
 }
+#endif // TW_NO_MINUI_CUSTOM_FONTS
+
+// Blends gr_current onto pix value, assumes alpha as most significant byte.
+static inline uint16_t pixel_blend16(uint8_t a, uint16_t pix) {
+  unsigned char orig[2];
+  orig[0] = (pix & 0xFF00) >> 8;
+  orig[1] = pix & 0x00FF;
+
+  /* This code is a little easier to read
+  unsigned oldred = (orig[1] >> 3);
+  unsigned oldgreen = (((orig[0] >> 5) << 3) + (orig[1] & 0x7));
+  unsigned oldblue = (orig[0] & 0x1F);
+
+  unsigned newred = (oldred * (255-a) + r5 * a) / 255;
+  unsigned newgreen = (oldgreen * (255-a) + g5 * a) / 255;
+  unsigned newblue = (oldblue * (255-a) + b5 * a) / 255;
+  */
+
+  unsigned newred = ((orig[1] >> 3) * (255-a) + gr_current_r5 * a) / 255;
+  unsigned newgreen = ((((orig[0] >> 5) << 3) + (orig[1] & 0x7)) * (255-a) + gr_current_g5 * a) / 255;
+  unsigned newblue = ((orig[0] & 0x1F) * (255-a) + gr_current_b5 * a) / 255;
+
+  uint16_t newpix = (newred << 10) + (newgreen << 5) + newblue;
+  return newpix;
+}
+
+// Blends gr_current onto pix value, assumes alpha as most significant byte.
+static inline uint32_t pixel_blend(uint8_t alpha, uint32_t pix) {
+  if (alpha == 255) return gr_current;
+  if (alpha == 0) return pix;
+  uint32_t pix_r = pix & 0xff;
+  uint32_t pix_g = pix & 0xff00;
+  uint32_t pix_b = pix & 0xff0000;
+  uint32_t cur_r = gr_current & 0xff;
+  uint32_t cur_g = gr_current & 0xff00;
+  uint32_t cur_b = gr_current & 0xff0000;
+
+  uint32_t out_r = (pix_r * (255 - alpha) + cur_r * alpha) / 255;
+  uint32_t out_g = (pix_g * (255 - alpha) + cur_g * alpha) / 255;
+  uint32_t out_b = (pix_b * (255 - alpha) + cur_b * alpha) / 255;
+
+  return (out_r & 0xff) | (out_g & 0xff00) | (out_b & 0xff0000) | (gr_current & 0xff000000);
+}
+
+// increments pixel pointer right, with current rotation.
+static void incr_x16(uint16_t** p, int row_pixels) {
+  if (rotation % 2) {
+    *p = *p + (rotation == 1 ? 1 : -1) * row_pixels;
+  } else {
+    *p = *p + (rotation ? -1 : 1);
+  }
+}
+
+// increments pixel pointer down, with current rotation.
+static void incr_y16(uint16_t** p, int row_pixels) {
+  if (rotation % 2) {
+    *p = *p + (rotation == 1 ? -1 : 1);
+  } else {
+    *p = *p + (rotation ? -1 : 1) * row_pixels;
+  }
+}
+
+// increments pixel pointer right, with current rotation.
+static void incr_x(uint32_t** p, int row_pixels) {
+  if (rotation % 2) {
+    *p = *p + (rotation == 1 ? 1 : -1) * row_pixels;
+  } else {
+    *p = *p + (rotation ? -1 : 1);
+  }
+}
+
+// increments pixel pointer down, with current rotation.
+static void incr_y(uint32_t** p, int row_pixels) {
+  if (rotation % 2) {
+    *p = *p + (rotation == 1 ? -1 : 1);
+  } else {
+    *p = *p + (rotation ? -1 : 1) * row_pixels;
+  }
+}
+
+// returns pixel pointer at given coordinates with rotation adjustment.
+static uint16_t* pixel_at16(GRSurface* surf, int x, int y, int row_pixels) {
+  switch (rotation) {
+    case ROTATION_NONE:
+      return reinterpret_cast<uint16_t*>(surf->data) + y * row_pixels + x;
+    case ROTATION_RIGHT:
+      return reinterpret_cast<uint16_t*>(surf->data) + x * row_pixels + (surf->width - y);
+    case ROTATION_DOWN:
+      return reinterpret_cast<uint16_t*>(surf->data) + (surf->height - 1 - y) * row_pixels +
+             (surf->width - 1 - x);
+    case ROTATION_LEFT:
+      return reinterpret_cast<uint16_t*>(surf->data) + (surf->height - 1 - x) * row_pixels + y;
+    default:
+      printf("invalid rotation %d", rotation);
+  }
+  return nullptr;
+}
+
+// returns pixel pointer at given coordinates with rotation adjustment.
+static uint32_t* pixel_at(GRSurface* surf, int x, int y, int row_pixels) {
+  switch (rotation) {
+    case ROTATION_NONE:
+      return reinterpret_cast<uint32_t*>(surf->data) + y * row_pixels + x;
+    case ROTATION_RIGHT:
+      return reinterpret_cast<uint32_t*>(surf->data) + x * row_pixels + (surf->width - y);
+    case ROTATION_DOWN:
+      return reinterpret_cast<uint32_t*>(surf->data) + (surf->height - 1 - y) * row_pixels +
+             (surf->width - 1 - x);
+    case ROTATION_LEFT:
+      return reinterpret_cast<uint32_t*>(surf->data) + (surf->height - 1 - x) * row_pixels + y;
+    default:
+      printf("invalid rotation %d", rotation);
+  }
+  return nullptr;
+}
+
+static void text_blend16(uint8_t* src_p, int src_row_bytes, uint16_t* dst_p, int dst_row_pixels,
+                       int width, int height) {
+  uint8_t alpha_current = static_cast<uint8_t>((alpha_mask & gr_current) >> 24);
+  for (int j = 0; j < height; ++j) {
+    uint8_t* sx = src_p;
+    uint16_t* px = dst_p;
+    for (int i = 0; i < width; ++i, incr_x16(&px, dst_row_pixels)) {
+      uint8_t a = *sx++;
+      if (alpha_current < 255) a = (static_cast<uint32_t>(a) * alpha_current) / 255;
+      *px = pixel_blend16(a, *px);
+    }
+    src_p += src_row_bytes;
+    incr_y16(&dst_p, dst_row_pixels);
+  }
+}
+
+static void text_blend(uint8_t* src_p, int src_row_bytes, uint32_t* dst_p, int dst_row_pixels,
+                       int width, int height) {
+  uint8_t alpha_current = static_cast<uint8_t>((alpha_mask & gr_current) >> 24);
+  for (int j = 0; j < height; ++j) {
+    uint8_t* sx = src_p;
+    uint32_t* px = dst_p;
+    for (int i = 0; i < width; ++i, incr_x(&px, dst_row_pixels)) {
+      uint8_t a = *sx++;
+      if (alpha_current < 255) a = (static_cast<uint32_t>(a) * alpha_current) / 255;
+      *px = pixel_blend(a, *px);
+    }
+    src_p += src_row_bytes;
+    incr_y(&dst_p, dst_row_pixels);
+  }
+}
+
 
 #ifdef TW_NO_MINUI_CUSTOM_FONTS
 void gr_text(int x, int y, const char *s, bool bold)
@@ -178,248 +331,284 @@ void gr_text(int x, int y, const char *s, bool bold)
                                (bold ? font->char_height * font->texture->row_bytes : 0);
         unsigned char* dst_p = gr_draw->data + y*gr_draw->row_bytes + x*gr_draw->pixel_bytes;
 
-        text_blend(src_p, font->texture->row_bytes,
-                   dst_p, gr_draw->row_bytes,
-                   font->char_width, font->char_height);
+        text_blend_old(src_p, font->texture->row_bytes,
+                       dst_p, gr_draw->row_bytes,
+                       font->char_width, font->char_height);
 
         x += font->char_width;
     }
 }
 #else //TW_NO_MINUI_CUSTOM_FONTS
-void gr_text(const GRFont* font, int x, int y, const char *s, bool bold)
-{
-    if (!font->texture || gr_current_a == 0) return;
+void gr_text(const GRFont* font, int x, int y, const char* s, bool bold) {
+  if (!font || !font->texture || (gr_current & alpha_mask) == 0) return;
 
-    bold = bold && (font->texture->height != font->char_height);
+  if (font->texture->pixel_bytes != 1) {
+    printf("gr_text: font has wrong format\n");
+    return;
+  }
 
-    x += overscan_offset_x;
-    y += overscan_offset_y;
+  bold = bold && (font->texture->height != font->char_height);
 
-    unsigned char ch;
-    while ((ch = *s++)) {
-        if (outside(x, y) || outside(x+font->char_width-1, y+font->char_height-1)) break;
+  x += overscan_offset_x;
+  y += overscan_offset_y;
 
-        if (ch < ' ' || ch > '~') {
-            ch = '?';
-        }
+  unsigned char ch;
+  while ((ch = *s++)) {
+    if (outside(x, y) || outside(x + font->char_width - 1, y + font->char_height - 1)) break;
 
-        unsigned char* src_p = font->texture->data + ((ch - ' ') * font->char_width) +
-                               (bold ? font->char_height * font->texture->row_bytes : 0);
-        unsigned char* dst_p = gr_draw->data + y*gr_draw->row_bytes + x*gr_draw->pixel_bytes;
+    if (ch < ' ' || ch > '~') {
+      ch = '?';
+    }
 
-        text_blend(src_p, font->texture->row_bytes,
-                   dst_p, gr_draw->row_bytes,
-                   font->char_width, font->char_height);
+    int row_pixels = gr_draw->row_bytes / gr_draw->pixel_bytes;
 
-        x += font->char_width;
+    uint8_t* src_p = font->texture->data + ((ch - ' ') * font->char_width) +
+                     (bold ? font->char_height * font->texture->row_bytes : 0);
+    if (gr_draw->pixel_bytes == 2) {
+      uint16_t* dst_p = pixel_at16(gr_draw, x, y, row_pixels);
+      
+      text_blend16(src_p, font->texture->row_bytes, dst_p, row_pixels, font->char_width,
+                   font->char_height);
+    } else { // not indenting AOSP original code
+    uint32_t* dst_p = pixel_at(gr_draw, x, y, row_pixels);
+
+    text_blend(src_p, font->texture->row_bytes, dst_p, row_pixels, font->char_width,
+               font->char_height);
     }
+    x += font->char_width;
+  }
 }
 #endif //TW_NO_MINUI_CUSTOM_FONTS
 
 void gr_texticon(int x, int y, GRSurface* icon) {
-    if (icon == NULL) return;
+  if (icon == NULL) return;
 
-    if (icon->pixel_bytes != 1) {
-        printf("gr_texticon: source has wrong format\n");
-        return;
-    }
+  if (icon->pixel_bytes != 1) {
+    printf("gr_texticon: source has wrong format\n");
+    return;
+  }
 
-    x += overscan_offset_x;
-    y += overscan_offset_y;
+  x += overscan_offset_x;
+  y += overscan_offset_y;
+
+  if (outside(x, y) || outside(x + icon->width - 1, y + icon->height - 1)) return;
 
-    if (outside(x, y) || outside(x+icon->width-1, y+icon->height-1)) return;
+  int row_pixels = gr_draw->row_bytes / gr_draw->pixel_bytes;
+  uint8_t* src_p = icon->data;
+  if (gr_draw->pixel_bytes == 2) {
+	uint16_t* dst_p = pixel_at16(gr_draw, x, y, row_pixels);
 
-    unsigned char* src_p = icon->data;
-    unsigned char* dst_p = gr_draw->data + y*gr_draw->row_bytes + x*gr_draw->pixel_bytes;
+    text_blend16(src_p, icon->row_bytes, dst_p, row_pixels, icon->width, icon->height);
+    return;
+  }
+  uint32_t* dst_p = pixel_at(gr_draw, x, y, row_pixels);
 
-    text_blend(src_p, icon->row_bytes,
-               dst_p, gr_draw->row_bytes,
-               icon->width, icon->height);
+  text_blend(src_p, icon->row_bytes, dst_p, row_pixels, icon->width, icon->height);
 }
 
-void gr_convert_rgb_555()
+void gr_convert_rgb_555(unsigned char r, unsigned char g, unsigned char b)
 {
-    gr_current_r5 = (((gr_current_r & 0xFF) * 0x1F) + 0x7F) / 0xFF;
-    gr_current_g5 = (((gr_current_g & 0xFF) * 0x3F) + 0x7F) / 0xFF;
-    gr_current_b5 = (((gr_current_b & 0xFF) * 0x1F) + 0x7F) / 0xFF;
+    gr_current_r5 = (((r & 0xFF) * 0x1F) + 0x7F) / 0xFF;
+    gr_current_g5 = (((g & 0xFF) * 0x3F) + 0x7F) / 0xFF;
+    gr_current_b5 = (((b & 0xFF) * 0x1F) + 0x7F) / 0xFF;
 
     rgb_555[0] = (gr_current_g5 << 5) + (gr_current_b5);
     rgb_555[1] = (gr_current_r5 << 3) + (gr_current_g5 >> 3);
 }
 
-void gr_color(unsigned char r, unsigned char g, unsigned char b, unsigned char a)
-{
+void gr_color(unsigned char r, unsigned char g, unsigned char b, unsigned char a) {
+#ifdef TW_NO_MINUI_CUSTOM_FONTS
 #if defined(RECOVERY_ABGR) || defined(RECOVERY_BGRA)
-    gr_current_r = b;
-    gr_current_g = g;
-    gr_current_b = r;
-    gr_current_a = a;
+  gr_current_r = b;
+  gr_current_g = g;
+  gr_current_b = r;
 #else
-    gr_current_r = r;
-    gr_current_g = g;
-    gr_current_b = b;
-    gr_current_a = a;
+  gr_current_r = r;
+  gr_current_g = g;
+  gr_current_b = b;
+#endif
 #endif
-    if (gr_draw->pixel_bytes == 2) {
-        gr_convert_rgb_555();
-    }
-}
 
-void gr_clear()
-{
-    if (gr_draw->pixel_bytes == 2) {
-        gr_fill(0, 0, gr_fb_width(), gr_fb_height());
-        return;
-    }
+  if (gr_draw->pixel_bytes == 2) {
+	gr_current_a = a;
+    gr_convert_rgb_555(r, g, b);
+    return;
+  }
 
-    // This code only works on 32bpp devices
-    if (gr_current_r == gr_current_g && gr_current_r == gr_current_b) {
-        memset(gr_draw->data, gr_current_r, gr_draw->height * gr_draw->row_bytes);
-    } else {
-        unsigned char* px = gr_draw->data;
-        for (int y = 0; y < gr_draw->height; ++y) {
-            for (int x = 0; x < gr_draw->width; ++x) {
-                *px++ = gr_current_r;
-                *px++ = gr_current_g;
-                *px++ = gr_current_b;
-                px++;
-            }
-            px += gr_draw->row_bytes - (gr_draw->width * gr_draw->pixel_bytes);
-        }
-    }
+  uint32_t r32 = r, g32 = g, b32 = b, a32 = a;
+#if defined(RECOVERY_ABGR) || defined(RECOVERY_BGRA)
+  gr_current = (a32 << 24) | (r32 << 16) | (g32 << 8) | b32;
+#else
+  gr_current = (a32 << 24) | (b32 << 16) | (g32 << 8) | r32;
+#endif
 }
 
-void gr_fill(int x1, int y1, int x2, int y2)
-{
-    x1 += overscan_offset_x;
-    y1 += overscan_offset_y;
-
-    x2 += overscan_offset_x;
-    y2 += overscan_offset_y;
+void gr_clear() {
+  if (gr_draw->pixel_bytes == 2) {
+    gr_fill(0, 0, gr_fb_width(), gr_fb_height());
+    return;
+  }
 
-    if (outside(x1, y1) || outside(x2-1, y2-1)) return;
+  // This code only works on 32bpp devices
+  if ((gr_current & 0xff) == ((gr_current >> 8) & 0xff) &&
+      (gr_current & 0xff) == ((gr_current >> 16) & 0xff) &&
+      (gr_current & 0xff) == ((gr_current >> 24) & 0xff) &&
+      gr_draw->row_bytes == gr_draw->width * gr_draw->pixel_bytes) {
+    memset(gr_draw->data, gr_current & 0xff, gr_draw->height * gr_draw->row_bytes);
+  } else {
+    uint32_t* px = reinterpret_cast<uint32_t*>(gr_draw->data);
+    int row_diff = gr_draw->row_bytes / gr_draw->pixel_bytes - gr_draw->width;
+    for (int y = 0; y < gr_draw->height; ++y) {
+      for (int x = 0; x < gr_draw->width; ++x) {
+        *px++ = gr_current;
+      }
+      px += row_diff;
+    }
+  }
+}
 
-    unsigned char* p = gr_draw->data + y1 * gr_draw->row_bytes + x1 * gr_draw->pixel_bytes;
-    if (gr_current_a == 255) {
-        int x, y;
-        for (y = y1; y < y2; ++y) {
-            unsigned char* px = p;
-            for (x = x1; x < x2; ++x) {
-                if (gr_draw->pixel_bytes == 2) {
-                    *px++ = rgb_555[0];
-                    *px++ = rgb_555[1];
-                } else {
-                    *px++ = gr_current_r;
-                    *px++ = gr_current_g;
-                    *px++ = gr_current_b;
-                    px++;
-                }
-            }
-            p += gr_draw->row_bytes;
-        }
-    } else if (gr_current_a > 0) {
-        int x, y;
-        for (y = y1; y < y2; ++y) {
-            unsigned char* px = p;
-            for (x = x1; x < x2; ++x) {
-                if (gr_draw->pixel_bytes == 2) {
-                    blend_16bpp(px, gr_current_r5, gr_current_g5, gr_current_b5, gr_current_a);
-                    px += gr_draw->row_bytes;
-                } else {
-                    *px = (*px * (255-gr_current_a) + gr_current_r * gr_current_a) / 255;
-                    ++px;
-                    *px = (*px * (255-gr_current_a) + gr_current_g * gr_current_a) / 255;
-                    ++px;
-                    *px = (*px * (255-gr_current_a) + gr_current_b * gr_current_a) / 255;
-                    ++px;
-                    ++px;
-                }
-            }
-            p += gr_draw->row_bytes;
+void gr_fill(int x1, int y1, int x2, int y2) {
+  x1 += overscan_offset_x;
+  y1 += overscan_offset_y;
+
+  x2 += overscan_offset_x;
+  y2 += overscan_offset_y;
+
+  if (outside(x1, y1) || outside(x2 - 1, y2 - 1)) return;
+
+  int row_pixels = gr_draw->row_bytes / gr_draw->pixel_bytes;
+  if (gr_draw->pixel_bytes == 2) {
+	uint16_t* p = pixel_at16(gr_draw, x1, y1, row_pixels);
+    uint8_t alpha = static_cast<uint8_t>(((gr_current & alpha_mask) >> 24));
+    if (alpha > 0) {
+      for (int y = y1; y < y2; ++y) {
+        uint16_t* px = p;
+        for (int x = x1; x < x2; ++x) {
+          *px = pixel_blend16(alpha, *px);
+          incr_x16(&px, row_pixels);
         }
+        incr_y16(&p, row_pixels);
+      }
     }
+	return;
+  }
+  { // open brace to maintain separation between uint16_t p and uint32_t p
+  uint32_t* p = pixel_at(gr_draw, x1, y1, row_pixels);
+  uint8_t alpha = static_cast<uint8_t>(((gr_current & alpha_mask) >> 24));
+  if (alpha > 0) {
+    for (int y = y1; y < y2; ++y) {
+      uint32_t* px = p;
+      for (int x = x1; x < x2; ++x) {
+        *px = pixel_blend(alpha, *px);
+        incr_x(&px, row_pixels);
+      }
+      incr_y(&p, row_pixels);
+    }
+  }
+  } // close brace to maintain separation between uint16_t p and uint32_t p
 }
 
 void gr_blit_32to16(GRSurface* source, int sx, int sy, int w, int h, int dx, int dy) {
-    dx += overscan_offset_x;
-    dy += overscan_offset_y;
-
-    if (outside(dx, dy) || outside(dx+w-1, dy+h-1)) return;
-
-    unsigned char* src_p = source->data + sy*source->row_bytes + sx*source->pixel_bytes;
-    unsigned char* dst_p = gr_draw->data + dy*gr_draw->row_bytes + dx*gr_draw->pixel_bytes;
-
-    int i, j;
-    for (i = 0; i < h; ++i) {
-        unsigned char* spx = src_p;
-        unsigned char* dpx = dst_p;
-
-        for (j = 0; j < w; ++j) {
-            unsigned a = spx[3];
-
-            if (a == 0) {
-                spx += source->pixel_bytes;
-                dpx += gr_draw->pixel_bytes;
-            } else {
-                unsigned r5 = (((*spx++ & 0xFF) * 0x1F) + 0x7F) / 0xFF;
-                unsigned g5 = (((*spx++ & 0xFF) * 0x3F) + 0x7F) / 0xFF;
-                unsigned b5 = (((*spx++ & 0xFF) * 0x1F) + 0x7F) / 0xFF;
-                spx++;
-                if (a == 255) {
-                    *dpx++ = (g5 << 5) + (b5);
-                    *dpx++ = (r5 << 3) + (g5 >> 3);
-                } else {
-                    blend_16bpp(dpx, r5, g5, b5, a);
-                    spx += source->pixel_bytes;
-                }
-            }
+  if (rotation)
+    printf("gr_blit_32to16 does not support rotation!\n"); // but we'll draw something in the wrong spot anyway because, why not!
+
+  dx += overscan_offset_x;
+  dy += overscan_offset_y;
+
+  if (outside(dx, dy) || outside(dx+w-1, dy+h-1)) return;
+
+  unsigned char* src_p = source->data + sy*source->row_bytes + sx*source->pixel_bytes;
+  unsigned char* dst_p = gr_draw->data + dy*gr_draw->row_bytes + dx*gr_draw->pixel_bytes;
+
+  int i, j;
+  for (i = 0; i < h; ++i) {
+    unsigned char* spx = src_p;
+    unsigned char* dpx = dst_p;
+
+    for (j = 0; j < w; ++j) {
+      unsigned a = spx[3];
+
+      if (a == 0) {
+        spx += source->pixel_bytes;
+        dpx += gr_draw->pixel_bytes;
+      } else {
+        unsigned r5 = (((*spx++ & 0xFF) * 0x1F) + 0x7F) / 0xFF;
+        unsigned g5 = (((*spx++ & 0xFF) * 0x3F) + 0x7F) / 0xFF;
+        unsigned b5 = (((*spx++ & 0xFF) * 0x1F) + 0x7F) / 0xFF;
+        spx++;
+        if (a == 255) {
+          *dpx++ = (g5 << 5) + (b5);
+          *dpx++ = (r5 << 3) + (g5 >> 3);
+        } else {
+          blend_16bpp(dpx, r5, g5, b5, a);
+          spx += source->pixel_bytes;
         }
-        src_p += source->row_bytes;
-        dst_p += gr_draw->row_bytes;
+      }
     }
+    src_p += source->row_bytes;
+    dst_p += gr_draw->row_bytes;
+  }
 }
 
 void gr_blit(GRSurface* source, int sx, int sy, int w, int h, int dx, int dy) {
-    if (source == NULL) return;
+  if (source == NULL) return;
 
-    if (gr_draw->pixel_bytes != source->pixel_bytes) {
-        if (gr_draw->pixel_bytes == 2 && source->pixel_bytes == 4) {
-            gr_blit_32to16(source, sx, sy, w, h, dx, dy);
-            return;
-        } else {
-            printf("gr_blit: source has wrong format\n");
-            return;
-        }
+  if (gr_draw->pixel_bytes != source->pixel_bytes) {
+    if (gr_draw->pixel_bytes == 2 && source->pixel_bytes == 4) {
+      gr_blit_32to16(source, sx, sy, w, h, dx, dy);
+      return;
+    } else {
+      printf("gr_blit: source has wrong format\n");
+      return;
     }
+  }
 
-    dx += overscan_offset_x;
-    dy += overscan_offset_y;
-
-    if (outside(dx, dy) || outside(dx+w-1, dy+h-1)) return;
-
-    unsigned char* src_p = source->data + sy*source->row_bytes + sx*source->pixel_bytes;
-    unsigned char* dst_p = gr_draw->data + dy*gr_draw->row_bytes + dx*gr_draw->pixel_bytes;
+  dx += overscan_offset_x;
+  dy += overscan_offset_y;
+
+  if (outside(dx, dy) || outside(dx + w - 1, dy + h - 1)) return;
+
+  if (rotation) {
+    int src_row_pixels = source->row_bytes / source->pixel_bytes;
+    int row_pixels = gr_draw->row_bytes / gr_draw->pixel_bytes;
+    uint32_t* src_py = reinterpret_cast<uint32_t*>(source->data) + sy * source->row_bytes / 4 + sx;
+    uint32_t* dst_py = pixel_at(gr_draw, dx, dy, row_pixels);
+
+    for (int y = 0; y < h; y += 1) {
+      uint32_t* src_px = src_py;
+      uint32_t* dst_px = dst_py;
+      for (int x = 0; x < w; x += 1) {
+        *dst_px = *src_px++;
+        incr_x(&dst_px, row_pixels);
+      }
+      src_py += src_row_pixels;
+      incr_y(&dst_py, row_pixels);
+    }
+  } else {
+    unsigned char* src_p = source->data + sy * source->row_bytes + sx * source->pixel_bytes;
+    unsigned char* dst_p = gr_draw->data + dy * gr_draw->row_bytes + dx * gr_draw->pixel_bytes;
 
     int i;
     for (i = 0; i < h; ++i) {
-        memcpy(dst_p, src_p, w * source->pixel_bytes);
-        src_p += source->row_bytes;
-        dst_p += gr_draw->row_bytes;
+      memcpy(dst_p, src_p, w * source->pixel_bytes);
+      src_p += source->row_bytes;
+      dst_p += gr_draw->row_bytes;
     }
+  }
 }
 
 unsigned int gr_get_width(GRSurface* surface) {
-    if (surface == NULL) {
-        return 0;
-    }
-    return surface->width;
+  if (surface == NULL) {
+    return 0;
+  }
+  return surface->width;
 }
 
 unsigned int gr_get_height(GRSurface* surface) {
-    if (surface == NULL) {
-        return 0;
-    }
-    return surface->height;
+  if (surface == NULL) {
+    return 0;
+  }
+  return surface->height;
 }
 
 #ifdef TW_NO_MINUI_CUSTOM_FONTS
@@ -466,58 +655,56 @@ void gr_set_font(__attribute__ ((unused))const char* name) {
 }
 #else // TW_NO_MINUI_CUSTOM_FONTS
 int gr_init_font(const char* name, GRFont** dest) {
-    GRFont* font = static_cast<GRFont*>(calloc(1, sizeof(*gr_font)));
-    if (font == nullptr) {
-        return -1;
-    }
+  GRFont* font = static_cast<GRFont*>(calloc(1, sizeof(*gr_font)));
+  if (font == nullptr) {
+    return -1;
+  }
 
-    int res = res_create_alpha_surface(name, &(font->texture));
-    if (res < 0) {
-        free(font);
-        return res;
-    }
+  int res = res_create_alpha_surface(name, &(font->texture));
+  if (res < 0) {
+    free(font);
+    return res;
+  }
 
-    // The font image should be a 96x2 array of character images.  The
-    // columns are the printable ASCII characters 0x20 - 0x7f.  The
-    // top row is regular text; the bottom row is bold.
-    font->char_width = font->texture->width / 96;
-    font->char_height = font->texture->height / 2;
+  // The font image should be a 96x2 array of character images.  The
+  // columns are the printable ASCII characters 0x20 - 0x7f.  The
+  // top row is regular text; the bottom row is bold.
+  font->char_width = font->texture->width / 96;
+  font->char_height = font->texture->height / 2;
 
-    *dest = font;
+  *dest = font;
 
-    return 0;
+  return 0;
 }
 
-static void gr_init_font(void)
-{
-    int res = gr_init_font("font", &gr_font);
-    if (res == 0) {
-        return;
-    }
-
-    printf("failed to read font: res=%d\n", res);
+static void gr_init_font(void) {
+  int res = gr_init_font("font", &gr_font);
+  if (res == 0) {
+    return;
+  }
 
+  printf("failed to read font: res=%d\n", res);
 
-    // fall back to the compiled-in font.
-    gr_font = static_cast<GRFont*>(calloc(1, sizeof(*gr_font)));
-    gr_font->texture = static_cast<GRSurface*>(malloc(sizeof(*gr_font->texture)));
-    gr_font->texture->width = font.width;
-    gr_font->texture->height = font.height;
-    gr_font->texture->row_bytes = font.width;
-    gr_font->texture->pixel_bytes = 1;
+  // fall back to the compiled-in font.
+  gr_font = static_cast<GRFont*>(calloc(1, sizeof(*gr_font)));
+  gr_font->texture = static_cast<GRSurface*>(malloc(sizeof(*gr_font->texture)));
+  gr_font->texture->width = font.width;
+  gr_font->texture->height = font.height;
+  gr_font->texture->row_bytes = font.width;
+  gr_font->texture->pixel_bytes = 1;
 
-    unsigned char* bits = static_cast<unsigned char*>(malloc(font.width * font.height));
-    gr_font->texture->data = bits;
+  unsigned char* bits = static_cast<unsigned char*>(malloc(font.width * font.height));
+  gr_font->texture->data = bits;
 
-    unsigned char data;
-    unsigned char* in = font.rundata;
-    while((data = *in++)) {
-        memset(bits, (data & 0x80) ? 255 : 0, data & 0x7f);
-        bits += (data & 0x7f);
-    }
+  unsigned char data;
+  unsigned char* in = font.rundata;
+  while ((data = *in++)) {
+    memset(bits, (data & 0x80) ? 255 : 0, data & 0x7f);
+    bits += (data & 0x7f);
+  }
 
-    gr_font->char_width = font.char_width;
-    gr_font->char_height = font.char_height;
+  gr_font->char_width = font.char_width;
+  gr_font->char_height = font.char_height;
 }
 #endif // TW_NO_MINUI_CUSTOM_FONTS
 
@@ -575,6 +762,12 @@ int gr_init(void)
   gr_flip();
   gr_flip();
 
+  gr_rotate(DEFAULT_ROTATION);
+
+  if (gr_draw->pixel_bytes != 4) {
+    printf("gr_init: Only 4-byte pixel formats supported\n");
+  }
+
   return 0;
 }
 
@@ -583,13 +776,19 @@ void gr_exit() {
 }
 
 int gr_fb_width() {
-  return gr_draw->width - 2 * overscan_offset_x;
+  return rotation % 2 ? gr_draw->height - 2 * overscan_offset_y
+                      : gr_draw->width - 2 * overscan_offset_x;
 }
 
 int gr_fb_height() {
-  return gr_draw->height - 2 * overscan_offset_y;
+  return rotation % 2 ? gr_draw->width - 2 * overscan_offset_x
+                      : gr_draw->height - 2 * overscan_offset_y;
 }
 
 void gr_fb_blank(bool blank) {
   gr_backend->Blank(blank);
 }
+
+void gr_rotate(GRRotation rot) {
+  rotation = rot;
+}
diff --git a/minui/graphics_overlay.cpp b/minui/graphics_overlay.cpp
index 082d385d9..b7e62d945 100644
--- a/minui/graphics_overlay.cpp
+++ b/minui/graphics_overlay.cpp
@@ -47,7 +47,6 @@
 #define ALIGN(x, align) (((x) + ((align)-1)) & ~((align)-1))
 
 MinuiBackendOverlay::MinuiBackendOverlay() :
-  gr_draw(nullptr),
   fb_fd(-1),
   isMDP5(false),
   leftSplit(0),
@@ -76,7 +75,6 @@ static memInfo mem_info;
 
 bool MinuiBackendOverlay::target_has_overlay()
 {
-    int ret;
     int mdp_version;
     bool overlay_supported = false;
     fb_fix_screeninfo fi;
@@ -524,6 +522,7 @@ int MinuiBackendOverlay::free_overlay(int fd)
 }
 
 GRSurface* MinuiBackendOverlay::Init() {
+	gr_draw = NULL; // this should be in the constructor but 9.0 was throwing a compile error
 	if (!target_has_overlay())
 	    return NULL;
 
diff --git a/minui/include/minui/minui.h b/minui/include/minui/minui.h
index bd8c3865d..bff146add 100644
--- a/minui/include/minui/minui.h
+++ b/minui/include/minui/minui.h
@@ -23,23 +23,31 @@
 
 #include <functional>
 #include <string>
+#include <vector>
 
 //
 // Graphics.
 //
 
 struct GRSurface {
-    int width;
-    int height;
-    int row_bytes;
-    int pixel_bytes;
-    unsigned char* data;
+  int width;
+  int height;
+  int row_bytes;
+  int pixel_bytes;
+  unsigned char* data;
 };
 
 struct GRFont {
-    GRSurface* texture;
-    int char_width;
-    int char_height;
+  GRSurface* texture;
+  int char_width;
+  int char_height;
+};
+
+enum GRRotation {
+  ROTATION_NONE = 0,
+  ROTATION_RIGHT = 1,
+  ROTATION_DOWN = 2,
+  ROTATION_LEFT = 3,
 };
 
 int gr_init();
@@ -65,15 +73,18 @@ void gr_set_font(__attribute__ ((unused))const char* name);
 
 const GRFont* gr_sys_font();
 int gr_init_font(const char* name, GRFont** dest);
-void gr_text(const GRFont* font, int x, int y, const char *s, bool bold);
-int gr_measure(const GRFont* font, const char *s);
-void gr_font_size(const GRFont* font, int *x, int *y);
+void gr_text(const GRFont* font, int x, int y, const char* s, bool bold);
+int gr_measure(const GRFont* font, const char* s);
+void gr_font_size(const GRFont* font, int* x, int* y);
 #endif
 
 void gr_blit(GRSurface* source, int sx, int sy, int w, int h, int dx, int dy);
 unsigned int gr_get_width(GRSurface* surface);
 unsigned int gr_get_height(GRSurface* surface);
 
+// Set rotation, flips gr_fb_width/height if 90 degree rotation difference
+void gr_rotate(GRRotation rotation);
+
 //
 // Input events.
 //
@@ -153,6 +164,9 @@ int res_create_alpha_surface(const char* name, GRSurface** pSurface);
 int res_create_localized_alpha_surface(const char* name, const char* locale,
                                        GRSurface** pSurface);
 
+// Return a list of locale strings embedded in |png_name|. Return a empty list in case of failure.
+std::vector<std::string> get_locales_in_png(const std::string& png_name);
+
 // Free a surface allocated by any of the res_create_*_surface()
 // functions.
 void res_free_surface(GRSurface* surface);
diff --git a/minui/main.cpp b/minui/main.cpp
index 13fee8746..4c3c52c31 100644
--- a/minui/main.cpp
+++ b/minui/main.cpp
@@ -89,11 +89,11 @@ int main() {
 	gr_color(255, 255, 255, 255);
 	gr_fill(0, 0, gr_fb_width(), gr_fb_height());
 	gr_color(255, 0, 0, 255);
-	gr_text(10, 10, "RED red RED", false);
+	gr_text(gr_sys_font(), 10, 10, "RED red RED", false);
 	gr_color(0, 255, 0, 255);
-	gr_text(10, 50, "GREEN green GREEN", false);
+	gr_text(gr_sys_font(), 10, 50, "GREEN green GREEN", false);
 	gr_color(0, 0, 255, 255);
-	gr_text(10, 90, "BLUE blue BLUE", false);
+	gr_text(gr_sys_font(), 10, 90, "BLUE blue BLUE", false);
 	gr_flip();
 	sleep(3);
 	printf("PNG test with /res/images/test.png\n");
diff --git a/minui/resources.cpp b/minui/resources.cpp
index b9797b905..fd5789374 100644
--- a/minui/resources.cpp
+++ b/minui/resources.cpp
@@ -25,10 +25,12 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+#include <memory>
 #include <regex>
 #include <string>
 #include <vector>
 
+//#include <android-base/stringprintf.h> // does not exist in 6.0
 //#include <android-base/strings.h> // does not exist in 6.0
 #include <png.h>
 
@@ -46,89 +48,128 @@ static GRSurface* malloc_surface(size_t data_size) {
     return surface;
 }
 
-static int open_png(const char* name, png_structp* png_ptr, png_infop* info_ptr,
-                    png_uint_32* width, png_uint_32* height, png_byte* channels) {
-    char resPath[256];
-    unsigned char header[8];
-    int result = 0;
-    int color_type, bit_depth;
-    size_t bytesRead;
-
-    snprintf(resPath, sizeof(resPath)-1, "/res/images/%s.png", name);
-    resPath[sizeof(resPath)-1] = '\0';
-    FILE* fp = fopen(resPath, "rbe");
-    if (fp == NULL) {
-        result = -1;
-        goto exit;
-    }
+// This class handles the png file parsing. It also holds the ownership of the png pointer and the
+// opened file pointer. Both will be destroyed/closed when this object goes out of scope.
+class PngHandler {
+ public:
+  PngHandler(const std::string& name);
 
-    bytesRead = fread(header, 1, sizeof(header), fp);
-    if (bytesRead != sizeof(header)) {
-        result = -2;
-        goto exit;
-    }
+  ~PngHandler();
 
-    if (png_sig_cmp(header, 0, sizeof(header))) {
-        result = -3;
-        goto exit;
-    }
+  png_uint_32 width() const {
+    return width_;
+  }
 
-    *png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
-    if (!*png_ptr) {
-        result = -4;
-        goto exit;
-    }
+  png_uint_32 height() const {
+    return height_;
+  }
 
-    *info_ptr = png_create_info_struct(*png_ptr);
-    if (!*info_ptr) {
-        result = -5;
-        goto exit;
-    }
+  png_byte channels() const {
+    return channels_;
+  }
 
-    if (setjmp(png_jmpbuf(*png_ptr))) {
-        result = -6;
-        goto exit;
-    }
+  png_structp png_ptr() const {
+    return png_ptr_;
+  }
 
-    png_init_io(*png_ptr, fp);
-    png_set_sig_bytes(*png_ptr, sizeof(header));
-    png_read_info(*png_ptr, *info_ptr);
-
-    png_get_IHDR(*png_ptr, *info_ptr, width, height, &bit_depth,
-            &color_type, NULL, NULL, NULL);
-
-    *channels = png_get_channels(*png_ptr, *info_ptr);
-
-    if (bit_depth == 8 && *channels == 3 && color_type == PNG_COLOR_TYPE_RGB) {
-        // 8-bit RGB images: great, nothing to do.
-    } else if (bit_depth <= 8 && *channels == 1 && color_type == PNG_COLOR_TYPE_GRAY) {
-        // 1-, 2-, 4-, or 8-bit gray images: expand to 8-bit gray.
-        png_set_expand_gray_1_2_4_to_8(*png_ptr);
-    } else if (bit_depth <= 8 && *channels == 1 && color_type == PNG_COLOR_TYPE_PALETTE) {
-        // paletted images: expand to 8-bit RGB.  Note that we DON'T
-        // currently expand the tRNS chunk (if any) to an alpha
-        // channel, because minui doesn't support alpha channels in
-        // general.
-        png_set_palette_to_rgb(*png_ptr);
-        *channels = 3;
-    } else {
-        fprintf(stderr, "minui doesn't support PNG depth %d channels %d color_type %d\n",
-                bit_depth, *channels, color_type);
-        result = -7;
-        goto exit;
-    }
+  png_infop info_ptr() const {
+    return info_ptr_;
+  }
 
-    return result;
+  int error_code() const {
+    return error_code_;
+  };
 
-  exit:
-    if (result < 0) {
-        png_destroy_read_struct(png_ptr, info_ptr, NULL);
-    }
-    if (fp != NULL) {
-        fclose(fp);
-    }
+  operator bool() const {
+    return error_code_ == 0;
+  }
+
+ private:
+  png_structp png_ptr_{ nullptr };
+  png_infop info_ptr_{ nullptr };
+  png_uint_32 width_;
+  png_uint_32 height_;
+  png_byte channels_;
+
+  // The |error_code_| is set to a negative value if an error occurs when opening the png file.
+  int error_code_;
+  // After initialization, we'll keep the file pointer open before destruction of PngHandler.
+  std::unique_ptr<FILE, decltype(&fclose)> png_fp_;
+};
+
+PngHandler::PngHandler(const std::string& name) : error_code_(0), png_fp_(nullptr, fclose) {
+  char res_path[PATH_MAX];
+  sprintf(res_path, "/res/images/%s.png", name.c_str());
+  //std::string res_path = sprintf("/res/images/%s.png", name.c_str());
+  png_fp_.reset(fopen(res_path, "rbe"));
+  if (!png_fp_) {
+    error_code_ = -1;
+    return;
+  }
+
+  unsigned char header[8];
+  size_t bytesRead = fread(header, 1, sizeof(header), png_fp_.get());
+  if (bytesRead != sizeof(header)) {
+    error_code_ = -2;
+    return;
+  }
+
+  if (png_sig_cmp(header, 0, sizeof(header))) {
+    error_code_ = -3;
+    return;
+  }
 
-    return result;
+  png_ptr_ = png_create_read_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
+  if (!png_ptr_) {
+    error_code_ = -4;
+    return;
+  }
+
+  info_ptr_ = png_create_info_struct(png_ptr_);
+  if (!info_ptr_) {
+    error_code_ = -5;
+    return;
+  }
+
+  if (setjmp(png_jmpbuf(png_ptr_))) {
+    error_code_ = -6;
+    return;
+  }
+
+  png_init_io(png_ptr_, png_fp_.get());
+  png_set_sig_bytes(png_ptr_, sizeof(header));
+  png_read_info(png_ptr_, info_ptr_);
+
+  int color_type;
+  int bit_depth;
+  png_get_IHDR(png_ptr_, info_ptr_, &width_, &height_, &bit_depth, &color_type, nullptr, nullptr,
+               nullptr);
+
+  channels_ = png_get_channels(png_ptr_, info_ptr_);
+
+  if (bit_depth == 8 && channels_ == 3 && color_type == PNG_COLOR_TYPE_RGB) {
+    // 8-bit RGB images: great, nothing to do.
+  } else if (bit_depth <= 8 && channels_ == 1 && color_type == PNG_COLOR_TYPE_GRAY) {
+    // 1-, 2-, 4-, or 8-bit gray images: expand to 8-bit gray.
+    png_set_expand_gray_1_2_4_to_8(png_ptr_);
+  } else if (bit_depth <= 8 && channels_ == 1 && color_type == PNG_COLOR_TYPE_PALETTE) {
+    // paletted images: expand to 8-bit RGB.  Note that we DON'T
+    // currently expand the tRNS chunk (if any) to an alpha
+    // channel, because minui doesn't support alpha channels in
+    // general.
+    png_set_palette_to_rgb(png_ptr_);
+    channels_ = 3;
+  } else {
+    fprintf(stderr, "minui doesn't support PNG depth %d channels %d color_type %d\n", bit_depth,
+            channels_, color_type);
+    error_code_ = -7;
+  }
+}
+
+PngHandler::~PngHandler() {
+  if (png_ptr_) {
+    png_destroy_read_struct(&png_ptr_, &info_ptr_, nullptr);
+  }
 }
 
 // "display" surfaces are transformed into the framebuffer's required
@@ -198,131 +239,115 @@ static void transform_rgb_to_draw(unsigned char* input_row,
 }
 
 int res_create_display_surface(const char* name, GRSurface** pSurface) {
-    GRSurface* surface = NULL;
-    int result = 0;
-    png_structp png_ptr = NULL;
-    png_infop info_ptr = NULL;
-    png_uint_32 width, height;
-    png_byte channels;
-    unsigned char* p_row;
-    unsigned int y;
-
-    *pSurface = NULL;
-
-    result = open_png(name, &png_ptr, &info_ptr, &width, &height, &channels);
-    if (result < 0) return result;
-
-    surface = init_display_surface(width, height);
-    if (surface == NULL) {
-        result = -8;
-        goto exit;
-    }
+  *pSurface = nullptr;
+
+  PngHandler png_handler(name);
+  if (!png_handler) return png_handler.error_code();
+
+  png_structp png_ptr = png_handler.png_ptr();
+  png_uint_32 width = png_handler.width();
+  png_uint_32 height = png_handler.height();
+
+  GRSurface* surface = init_display_surface(width, height);
+  if (!surface) {
+    return -8;
+  }
 
 #if defined(RECOVERY_ABGR) || defined(RECOVERY_BGRA)
-    png_set_bgr(png_ptr);
+  png_set_bgr(png_ptr);
 #endif
 
-    p_row = static_cast<unsigned char*>(malloc(width * 4));
-    for (y = 0; y < height; ++y) {
-        png_read_row(png_ptr, p_row, NULL);
-        transform_rgb_to_draw(p_row, surface->data + y * surface->row_bytes, channels, width);
-    }
-    free(p_row);
+  for (png_uint_32 y = 0; y < height; ++y) {
+    std::vector<unsigned char> p_row(width * 4);
+    png_read_row(png_ptr, p_row.data(), nullptr);
+    transform_rgb_to_draw(p_row.data(), surface->data + y * surface->row_bytes,
+                          png_handler.channels(), width);
+  }
 
-    *pSurface = surface;
+  *pSurface = surface;
 
-  exit:
-    png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
-    if (result < 0 && surface != NULL) free(surface);
-    return result;
+  return 0;
 }
 
 int res_create_multi_display_surface(const char* name, int* frames, int* fps,
-        GRSurface*** pSurface) {
-    GRSurface** surface = NULL;
-    int result = 0;
-    png_structp png_ptr = NULL;
-    png_infop info_ptr = NULL;
-    png_uint_32 width, height;
-    png_byte channels;
-    png_textp text;
-    int num_text;
-    unsigned char* p_row;
-    unsigned int y;
-
-    *pSurface = NULL;
-    *frames = -1;
-
-    result = open_png(name, &png_ptr, &info_ptr, &width, &height, &channels);
-    if (result < 0) return result;
-
-    *frames = 1;
-    *fps = 20;
-    if (png_get_text(png_ptr, info_ptr, &text, &num_text)) {
-        for (int i = 0; i < num_text; ++i) {
-            if (text[i].key && strcmp(text[i].key, "Frames") == 0 && text[i].text) {
-                *frames = atoi(text[i].text);
-            } else if (text[i].key && strcmp(text[i].key, "FPS") == 0 && text[i].text) {
-                *fps = atoi(text[i].text);
-            }
-        }
-        printf("  found frames = %d\n", *frames);
-        printf("  found fps = %d\n", *fps);
+                                     GRSurface*** pSurface) {
+  *pSurface = nullptr;
+  *frames = -1;
+
+  PngHandler png_handler(name);
+  if (!png_handler) return png_handler.error_code();
+
+  png_structp png_ptr = png_handler.png_ptr();
+  png_uint_32 width = png_handler.width();
+  png_uint_32 height = png_handler.height();
+
+  *frames = 1;
+  *fps = 20;
+  png_textp text;
+  int num_text;
+  if (png_get_text(png_ptr, png_handler.info_ptr(), &text, &num_text)) {
+    for (int i = 0; i < num_text; ++i) {
+      if (text[i].key && strcmp(text[i].key, "Frames") == 0 && text[i].text) {
+        *frames = atoi(text[i].text);
+      } else if (text[i].key && strcmp(text[i].key, "FPS") == 0 && text[i].text) {
+        *fps = atoi(text[i].text);
+      }
     }
+    printf("  found frames = %d\n", *frames);
+    printf("  found fps = %d\n", *fps);
+  }
 
-    if (*frames <= 0 || *fps <= 0) {
-        printf("bad number of frames (%d) and/or FPS (%d)\n", *frames, *fps);
-        result = -10;
-        goto exit;
-    }
+  int result = 0;
+  GRSurface** surface = nullptr;
+  if (*frames <= 0 || *fps <= 0) {
+    printf("bad number of frames (%d) and/or FPS (%d)\n", *frames, *fps);
+    result = -10;
+    goto exit;
+  }
 
-    if (height % *frames != 0) {
-        printf("bad height (%d) for frame count (%d)\n", height, *frames);
-        result = -9;
-        goto exit;
-    }
+  if (height % *frames != 0) {
+    printf("bad height (%d) for frame count (%d)\n", height, *frames);
+    result = -9;
+    goto exit;
+  }
 
-    surface = static_cast<GRSurface**>(calloc(*frames, sizeof(GRSurface*)));
-    if (surface == NULL) {
-        result = -8;
-        goto exit;
-    }
-    for (int i = 0; i < *frames; ++i) {
-        surface[i] = init_display_surface(width, height / *frames);
-        if (surface[i] == NULL) {
-            result = -8;
-            goto exit;
-        }
+  surface = static_cast<GRSurface**>(calloc(*frames, sizeof(GRSurface*)));
+  if (!surface) {
+    result = -8;
+    goto exit;
+  }
+  for (int i = 0; i < *frames; ++i) {
+    surface[i] = init_display_surface(width, height / *frames);
+    if (!surface[i]) {
+      result = -8;
+      goto exit;
     }
+  }
 
 #if defined(RECOVERY_ABGR) || defined(RECOVERY_BGRA)
-    png_set_bgr(png_ptr);
+  png_set_bgr(png_ptr);
 #endif
 
-    p_row = static_cast<unsigned char*>(malloc(width * 4));
-    for (y = 0; y < height; ++y) {
-        png_read_row(png_ptr, p_row, NULL);
-        int frame = y % *frames;
-        unsigned char* out_row = surface[frame]->data +
-            (y / *frames) * surface[frame]->row_bytes;
-        transform_rgb_to_draw(p_row, out_row, channels, width);
-    }
-    free(p_row);
+  for (png_uint_32 y = 0; y < height; ++y) {
+    std::vector<unsigned char> p_row(width * 4);
+    png_read_row(png_ptr, p_row.data(), nullptr);
+    int frame = y % *frames;
+    unsigned char* out_row = surface[frame]->data + (y / *frames) * surface[frame]->row_bytes;
+    transform_rgb_to_draw(p_row.data(), out_row, png_handler.channels(), width);
+  }
 
-    *pSurface = surface;
+  *pSurface = surface;
 
 exit:
-    png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
-
-    if (result < 0) {
-        if (surface) {
-            for (int i = 0; i < *frames; ++i) {
-                free(surface[i]);
-            }
-            free(surface);
-        }
+  if (result < 0) {
+    if (surface) {
+      for (int i = 0; i < *frames; ++i) {
+        free(surface[i]);
+      }
+      free(surface);
     }
-    return result;
+  }
+  return result;
 }
 
 int res_create_multi_display_surface(const char* name, int* frames,
@@ -332,50 +357,40 @@ int res_create_multi_display_surface(const char* name, int* frames,
 }
 
 int res_create_alpha_surface(const char* name, GRSurface** pSurface) {
-    GRSurface* surface = NULL;
-    int result = 0;
-    png_structp png_ptr = NULL;
-    png_infop info_ptr = NULL;
-    png_uint_32 width, height;
-    png_byte channels;
+  *pSurface = nullptr;
 
-    *pSurface = NULL;
+  PngHandler png_handler(name);
+  if (!png_handler) return png_handler.error_code();
 
-    result = open_png(name, &png_ptr, &info_ptr, &width, &height, &channels);
-    if (result < 0) return result;
+  if (png_handler.channels() != 1) {
+    return -7;
+  }
 
-    if (channels != 1) {
-        result = -7;
-        goto exit;
-    }
+  png_structp png_ptr = png_handler.png_ptr();
+  png_uint_32 width = png_handler.width();
+  png_uint_32 height = png_handler.height();
 
-    surface = malloc_surface(width * height);
-    if (surface == NULL) {
-        result = -8;
-        goto exit;
-    }
-    surface->width = width;
-    surface->height = height;
-    surface->row_bytes = width;
-    surface->pixel_bytes = 1;
+  GRSurface* surface = malloc_surface(width * height);
+  if (!surface) {
+    return -8;
+  }
+  surface->width = width;
+  surface->height = height;
+  surface->row_bytes = width;
+  surface->pixel_bytes = 1;
 
 #if defined(RECOVERY_ABGR) || defined(RECOVERY_BGRA)
-    png_set_bgr(png_ptr);
+  png_set_bgr(png_ptr);
 #endif
 
-    unsigned char* p_row;
-    unsigned int y;
-    for (y = 0; y < height; ++y) {
-        p_row = surface->data + y * surface->row_bytes;
-        png_read_row(png_ptr, p_row, NULL);
-    }
+  for (png_uint_32 y = 0; y < height; ++y) {
+    unsigned char* p_row = surface->data + y * surface->row_bytes;
+    png_read_row(png_ptr, p_row, nullptr);
+  }
 
-    *pSurface = surface;
+  *pSurface = surface;
 
-  exit:
-    png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
-    if (result < 0 && surface != NULL) free(surface);
-    return result;
+  return 0;
 }
 
 // This function tests if a locale string stored in PNG (prefix) matches
@@ -390,7 +405,7 @@ bool matches_locale(const std::string& prefix, const std::string& locale) {
   // match the locale string without the {script} section.
   // For instance, prefix == "en" matches locale == "en-US", prefix == "sr-Latn" matches locale
   // == "sr-Latn-BA", and prefix == "zh-CN" matches locale == "zh-Hans-CN".
-  //if (android::base::StartsWith(locale, prefix.c_str())) { // does not exist in 6.0
+  //if (android::base::StartsWith(locale, prefix)) { // does not exist in 6.0
   if (strncmp(prefix.c_str(), locale.c_str(), prefix.length()) == 0) {
     return true;
   }
@@ -403,75 +418,90 @@ bool matches_locale(const std::string& prefix, const std::string& locale) {
   return std::regex_match(locale, loc_regex);
 }
 
+std::vector<std::string> get_locales_in_png(const std::string& png_name) {
+  PngHandler png_handler(png_name);
+  if (!png_handler) {
+    printf("Failed to open %s, error: %d\n", png_name.c_str(), png_handler.error_code());
+    return {};
+  }
+  if (png_handler.channels() != 1) {
+    printf("Expect input png to have 1 data channel, this file has %d\n", png_handler.channels());
+    return {};
+  }
+
+  std::vector<std::string> result;
+  std::vector<unsigned char> row(png_handler.width());
+  for (png_uint_32 y = 0; y < png_handler.height(); ++y) {
+    png_read_row(png_handler.png_ptr(), row.data(), nullptr);
+    int h = (row[3] << 8) | row[2];
+    std::string loc(reinterpret_cast<char*>(&row[5]));
+    if (!loc.empty()) {
+      result.push_back(loc);
+    }
+    for (int i = 0; i < h; ++i, ++y) {
+      png_read_row(png_handler.png_ptr(), row.data(), nullptr);
+    }
+  }
+
+  return result;
+}
+
 int res_create_localized_alpha_surface(const char* name,
                                        const char* locale,
                                        GRSurface** pSurface) {
-    GRSurface* surface = NULL;
-    int result = 0;
-    png_structp png_ptr = NULL;
-    png_infop info_ptr = NULL;
-    png_uint_32 width, height;
-    png_byte channels;
-    png_uint_32 y;
-    std::vector<unsigned char> row;
-
-    *pSurface = NULL;
-
-    if (locale == NULL) {
-        return result;
-    }
+  *pSurface = nullptr;
+  if (locale == nullptr) {
+    return 0;
+  }
 
-    result = open_png(name, &png_ptr, &info_ptr, &width, &height, &channels);
-    if (result < 0) return result;
+  PngHandler png_handler(name);
+  if (!png_handler) return png_handler.error_code();
 
-    if (channels != 1) {
-        result = -7;
-        goto exit;
-    }
+  if (png_handler.channels() != 1) {
+    return -7;
+  }
 
-    row.resize(width);
-    for (y = 0; y < height; ++y) {
-        png_read_row(png_ptr, row.data(), NULL);
-        int w = (row[1] << 8) | row[0];
-        int h = (row[3] << 8) | row[2];
-        __unused int len = row[4];
-        char* loc = reinterpret_cast<char*>(&row[5]);
-
-        if (y+1+h >= height || matches_locale(loc, locale)) {
-            printf("  %20s: %s (%d x %d @ %d)\n", name, loc, w, h, y);
-
-            surface = malloc_surface(w*h);
-            if (surface == NULL) {
-                result = -8;
-                goto exit;
-            }
-            surface->width = w;
-            surface->height = h;
-            surface->row_bytes = w;
-            surface->pixel_bytes = 1;
-
-            int i;
-            for (i = 0; i < h; ++i, ++y) {
-                png_read_row(png_ptr, row.data(), NULL);
-                memcpy(surface->data + i*w, row.data(), w);
-            }
+  png_structp png_ptr = png_handler.png_ptr();
+  png_uint_32 width = png_handler.width();
+  png_uint_32 height = png_handler.height();
+
+  for (png_uint_32 y = 0; y < height; ++y) {
+    std::vector<unsigned char> row(width);
+    png_read_row(png_ptr, row.data(), nullptr);
+    int w = (row[1] << 8) | row[0];
+    int h = (row[3] << 8) | row[2];
+    __unused int len = row[4];
+    char* loc = reinterpret_cast<char*>(&row[5]);
+
+    if (y + 1 + h >= height || matches_locale(loc, locale)) {
+      printf("  %20s: %s (%d x %d @ %d)\n", name, loc, w, h, y);
+
+      GRSurface* surface = malloc_surface(w * h);
+      if (!surface) {
+        return -8;
+      }
+      surface->width = w;
+      surface->height = h;
+      surface->row_bytes = w;
+      surface->pixel_bytes = 1;
+
+      for (int i = 0; i < h; ++i, ++y) {
+        png_read_row(png_ptr, row.data(), nullptr);
+        memcpy(surface->data + i * w, row.data(), w);
+      }
+
+      *pSurface = surface;
+      break;
+    }
 
-            *pSurface = surface;
-            break;
-        } else {
-            int i;
-            for (i = 0; i < h; ++i, ++y) {
-                png_read_row(png_ptr, row.data(), NULL);
-            }
-        }
+    for (int i = 0; i < h; ++i, ++y) {
+      png_read_row(png_ptr, row.data(), nullptr);
     }
+  }
 
-exit:
-    png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
-    if (result < 0 && surface != NULL) free(surface);
-    return result;
+  return 0;
 }
 
 void res_free_surface(GRSurface* surface) {
-    free(surface);
+  free(surface);
 }