Wind Waker / Twilight Princess: Fix sun PeekZ

We were testing if the sun's position was obscured by something closer. However, the game only places the sun 8000 units away, which is very easy to hit with one of the bigger maps. The original game seems to test if the depth buffer has *anything* in it at all. I can't recall exactly why I went with the projected Z thing, so just do this instead.

src/ZeldaTwilightPrincess/d_kankyo_wether.ts

@@ -16,7 +16,7 @@ import { mDoLib_project, mDoLib_projectFB } from "../ZeldaWindWaker/m_do_ext.js"
 import { MtxTrans, calc_mtx, mDoMtx_XrotM, mDoMtx_ZrotM } from "../ZeldaWindWaker/m_do_mtx.js";
 import { fullscreenMegaState, setAttachmentStateSimple } from "../gfx/helpers/GfxMegaStateDescriptorHelpers.js";
 import { GfxShaderLibrary } from "../gfx/helpers/GfxShaderLibrary.js";
-import { compareDepthValues } from "../gfx/helpers/ReversedDepthHelpers.js";
+import { compareDepthValues, reverseDepthForClearValue } from "../gfx/helpers/ReversedDepthHelpers.js";
 import { fillColor, fillVec4 } from "../gfx/helpers/UniformBufferHelpers.js";
 import { GfxBindingLayoutDescriptor, GfxBlendFactor, GfxBlendMode, GfxClipSpaceNearZ, GfxCompareMode, GfxDevice, GfxFormat, GfxMipFilterMode, GfxTexFilterMode, GfxWrapMode } from "../gfx/platform/GfxPlatform.js";
 import { GfxProgram } from "../gfx/platform/GfxPlatformImpl.js";
@@ -1481,18 +1481,8 @@ function dKyr_sun_move__PeekZ(dst: PeekZResult, peekZ: PeekZManager, v: Readonly
     if (dst.value === null)
         return SunPeekZResult.Obscured;
 
-    // Test if the depth buffer is less than our projected Z coordinate.
-    // Depth buffer readback should result in 0.0 for the near plane, and 1.0 for the far plane.
-    // Put projected coordinate in 0-1 normalized space.
-    let projectedZ = v[2];
-
-    if (clipSpaceNearZ === GfxClipSpaceNearZ.NegativeOne)
-        projectedZ = projectedZ * 0.5 + 0.5;
-
-    // Point is visible if our projected Z is in front of the depth buffer.
-    const visible = compareDepthValues(projectedZ, dst.value, GfxCompareMode.Less);
-
-    return visible ? SunPeekZResult.Visible : SunPeekZResult.Obscured;
+    const obscured = compareDepthValues(dst.value, reverseDepthForClearValue(1.0), GfxCompareMode.Less);
+    return obscured ? SunPeekZResult.Obscured : SunPeekZResult.Visible;
 }
 
 function dKyr_sun_move(globals: dGlobals, deltaTimeFrames: number): void {

src/ZeldaWindWaker/d_kankyo_wether.ts

@@ -9,7 +9,7 @@ import { BTIData, BTI_Texture } from "../Common/JSYSTEM/JUTTexture.js";
 import { dfRange, dfShow } from "../DebugFloaters.js";
 import { MathConstants, clamp, computeMatrixWithoutTranslation, computeModelMatrixR, invlerp, saturate, vec3SetAll } from "../MathHelpers.js";
 import { TDDraw } from "../SuperMarioGalaxy/DDraw.js";
-import { compareDepthValues } from "../gfx/helpers/ReversedDepthHelpers.js";
+import { compareDepthValues, reverseDepthForClearValue } from "../gfx/helpers/ReversedDepthHelpers.js";
 import { GfxClipSpaceNearZ, GfxCompareMode, GfxDevice } from "../gfx/platform/GfxPlatform.js";
 import { GfxRenderInst, GfxRenderInstManager } from "../gfx/render/GfxRenderInstManager.js";
 import { GXMaterialBuilder } from "../gx/GXMaterialBuilder.js";
@@ -1578,18 +1578,8 @@ function dKyr_sun_move__PeekZ(dst: PeekZResult, peekZ: PeekZManager, v: Readonly
     if (dst.value === null)
         return SunPeekZResult.Obscured;
 
-    // Test if the depth buffer is less than our projected Z coordinate.
-    // Depth buffer readback should result in 0.0 for the near plane, and 1.0 for the far plane.
-    // Put projected coordinate in 0-1 normalized space.
-    let projectedZ = v[2];
-
-    if (clipSpaceNearZ === GfxClipSpaceNearZ.NegativeOne)
-        projectedZ = projectedZ * 0.5 + 0.5;
-
-    // Point is visible if our projected Z is in front of the depth buffer.
-    const visible = compareDepthValues(projectedZ, dst.value, GfxCompareMode.Less);
-
-    return visible ? SunPeekZResult.Visible : SunPeekZResult.Obscured;
+    const obscured = compareDepthValues(dst.value, reverseDepthForClearValue(1.0), GfxCompareMode.Less);
+    return obscured ? SunPeekZResult.Obscured : SunPeekZResult.Visible;
 }
 
 function dKyr_sun_move(globals: dGlobals): void {