last hurrah from me

Minecraft.Client/Platform_Libs/Dev/RenderVk/VulkanRenderManager.cpp

@@ -13,9 +13,11 @@
 #define STB_IMAGE_IMPLEMENTATION
 #define STBI_ONLY_PNG
 #define STBI_ONLY_JPEG
-#define STBI_NO_STDIO
 #include "stb_image.h"
 
+#define STB_TRUETYPE_IMPLEMENTATION
+#include "stb_truetype.h"
+
 #include "VulkanBootstrapApp.h"
 
 #include <algorithm>
@@ -31,6 +33,12 @@
 
 VulkanBootstrapApp g_vulkanBackend;
 
+// Brightness multiplier derived from the gamma setting.  Updated by
+// C4JRender::UpdateGamma each time the user moves the brightness slider.
+// Range maps from ucGamma 0-32768 -> multiplier ~0.5 (dark) to ~2.0 (bright),
+// with the midpoint (gamma 0.5) producing a multiplier of 1.0 (no change).
+static float g_brightnessMul = 1.0f;
+
 namespace
 {
 
@@ -412,9 +420,9 @@ ConvertParams buildConvertParams()
   }
   else
   {
-    params.colourScale[0] = context.renderState.colour[0];
-    params.colourScale[1] = context.renderState.colour[1];
-    params.colourScale[2] = context.renderState.colour[2];
+    params.colourScale[0] = context.renderState.colour[0] * g_brightnessMul;
+    params.colourScale[1] = context.renderState.colour[1] * g_brightnessMul;
+    params.colourScale[2] = context.renderState.colour[2] * g_brightnessMul;
     params.colourScale[3] = context.renderState.colour[3];
   }
   // Blend factor alpha applies to per-vertex alpha in both recording and
@@ -909,8 +917,15 @@ void C4JRender::Shutdown()
 void C4JRender::Tick() {}
 void C4JRender::UpdateGamma(unsigned short usGamma)
 {
-  extern void Windows64_UpdateGamma(unsigned short);
-  Windows64_UpdateGamma(usGamma);
+  // usGamma range is 0-32768 (ucGamma 0-100 scaled by 327.68).
+  // Map to a 0.0-1.0 normalised value, then derive a brightness multiplier
+  // using the same power curve the old glfwSetGamma path used:
+  //   multiplier = 0.5 * 4^gamma
+  // gamma 0.0 -> 0.5 (darker),  0.5 -> 1.0 (normal),  1.0 -> 2.0 (bright).
+  float gamma = static_cast<float>(usGamma) / 32768.0f;
+  if (gamma < 0.0f) gamma = 0.0f;
+  if (gamma > 1.0f) gamma = 1.0f;
+  g_brightnessMul = 0.5f * std::pow(4.0f, gamma);
 }
 void C4JRender::MatrixMode(int type) { getThreadContext().currentMatrixMode = type; }
 
@@ -1273,8 +1288,10 @@ bool C4JRender::CBuffCall(int index, bool)
   currentState.textureIndex = context.currentTextureIndex;
 
   const auto &colour = context.renderState.colour;
+  const float bMul = g_brightnessMul;
   const bool needsColourModulation =
-    colour[0] != 1.0f || colour[1] != 1.0f || colour[2] != 1.0f || colour[3] != 1.0f;
+    colour[0] != 1.0f || colour[1] != 1.0f || colour[2] != 1.0f || colour[3] != 1.0f ||
+    bMul != 1.0f;
 
   // Hoist shader variant outside the loop — the texture index and render state
   // don't change during display list replay, so this is invariant.
@@ -1284,7 +1301,8 @@ bool C4JRender::CBuffCall(int index, bool)
     : determineShaderVariant(currentState.textureIndex);
 
   // Pre-build the colour modulation array once instead of per-draw.
-  const float colorMod[4] = {colour[0], colour[1], colour[2], colour[3]};
+  // Fold brightness into the RGB channels so display list replay picks it up.
+  const float colorMod[4] = {colour[0] * bMul, colour[1] * bMul, colour[2] * bMul, colour[3]};
 
   // Apply the GL_TEXTURE matrix to UV coordinates when it is non-identity.
   // The precompiled item mesh (ItemInHandRenderer::list) stores UVs in the