feat(jui): add merchant screen

Minecraft.Client/UI/TradeSwitchButton.cpp

@@ -0,0 +1,46 @@
+#include "../../Platform/stdafx.h"
+#include "TradeSwitchButton.h"
+#include "../Textures/Textures.h"
+#include "../Rendering/Tesselator.h"
+#include "../../../Minecraft.Client/Minecraft.h"
+#include "../../../Minecraft.World/Headers/net.minecraft.locale.h"
+#include "../../../Minecraft.World/Containers/MerchantMenu.h"
+
+// 4jcraft: referenced from MCP 8.11 (JE 1.6.4)
+#ifdef ENABLE_JAVA_GUIS
+// ResourceLocation GUI_VILLAGER_LOCATION = ResourceLocation(TN_GUI_VILLAGER);
+extern ResourceLocation GUI_VILLAGER_LOCATION;
+#endif
+
+TradeSwitchButton::TradeSwitchButton(int id, int x, int y, bool mirrored)
+    : Button(id, x, y, 12, 19, L"") {
+    this->mirrored = mirrored;
+}
+
+int TradeSwitchButton::getYImage(bool hovered) { return 0; }
+
+void TradeSwitchButton::renderBg(Minecraft* minecraft, int xm, int ym) {
+#ifdef ENABLE_JAVA_GUIS
+    if (!visible) return;
+
+    glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
+    minecraft->textures->bindTexture(&GUI_VILLAGER_LOCATION);
+
+    bool hovered = (xm >= x && ym >= y && xm < x + w && ym < y + h);
+
+    int textureX = 176;
+    int textureY = 0;
+
+    if (!active) {
+        textureX += w * 2;
+    } else if (hovered) {
+        textureX += w;
+    }
+
+    if (!mirrored) {
+        textureY += h;
+    }
+
+    blit(x, y, textureX, textureY, w, h);
+#endif
+}