From fe086a089da50b4c63ba49003d607d05df850f26 Mon Sep 17 00:00:00 2001
From: UnknownShadow200 <unknownshadow200@gmail.com>
Date: Sun, 2 Mar 2025 14:17:10 +1100
Subject: [PATCH] NDS: Implement water translucency partially

---
 src/Graphics_NDS.c  | 13 ++++++-------
 src/_GraphicsBase.h |  4 ++--
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/src/Graphics_NDS.c b/src/Graphics_NDS.c
index 7d6535de6..01b28d9b5 100644
--- a/src/Graphics_NDS.c
+++ b/src/Graphics_NDS.c
@@ -101,7 +101,7 @@ void ResetGPU(void) {
 
 	GFX_ALPHA_TEST = 7; // Alpha threshold ranges from 0 to 15
 	
-	GFX_CONTROL = GL_ANTIALIAS | GL_TEXTURE_2D | GL_FOG;
+	GFX_CONTROL = GL_ANTIALIAS | GL_TEXTURE_2D | GL_FOG | GL_BLEND;
 
 	GFX_CLEAR_DEPTH = GL_MAX_DEPTH;
     GFX_TEX_FORMAT  = 0;
@@ -703,14 +703,16 @@ void Gfx_DeleteDynamicVb(GfxResourceID* vb) { Gfx_DeleteVb(vb); }
 *#########################################################################################################################*/
 static cc_bool skipRendering;
 static cc_bool backfaceCull;
+static cc_bool alphaBlend;
 
 static cc_bool fogEnabled;
 static FogFunc fogMode;
 static float fogDensityEnd;
 
 static void SetPolygonMode() {
+	int blend = !gfx_rendering2D && alphaBlend;
 	u32 fmt =
-		POLY_ALPHA(31) | 
+		POLY_ALPHA(blend ? 14 : 31) | 
 		(backfaceCull ? POLY_CULL_BACK : POLY_CULL_NONE) | 
 		(fogEnabled ? POLY_FOG : 0) | 
 		POLY_RENDER_FAR_POLYS | 
@@ -725,11 +727,8 @@ void Gfx_SetFaceCulling(cc_bool enabled) {
 }
 
 static void SetAlphaBlend(cc_bool enabled) {
-	/*if (enabled) {
-		glEnable(GL_BLEND);
-	} else {
-		glDisable(GL_BLEND);
-	}*/
+	alphaBlend = enabled;
+	SetPolygonMode();
 }
 
 void Gfx_SetAlphaArgBlend(cc_bool enabled) { }
diff --git a/src/_GraphicsBase.h b/src/_GraphicsBase.h
index e5d8e9e4e..75f26a42b 100644
--- a/src/_GraphicsBase.h
+++ b/src/_GraphicsBase.h
@@ -243,6 +243,7 @@ void Gfx_Make2DQuad(const struct Texture* tex, PackedCol color, struct VertexTex
 static cc_bool gfx_hadFog;
 
 void Gfx_Begin2D(int width, int height) {
+	gfx_rendering2D = true;
 	struct Matrix ortho;
 	/* intentionally biased more towards positive Z to reduce 2D clipping issues on the DS */
 	Gfx_CalcOrthoMatrix(&ortho, (float)width, (float)height, -100.0f, 1000.0f);
@@ -255,16 +256,15 @@ void Gfx_Begin2D(int width, int height) {
 	
 	gfx_hadFog = Gfx_GetFog();
 	if (gfx_hadFog) Gfx_SetFog(false);
-	gfx_rendering2D = true;
 }
 
 void Gfx_End2D(void) {
+	gfx_rendering2D = false;
 	Gfx_SetDepthTest(true);
 	Gfx_SetDepthWrite(true);
 	Gfx_SetAlphaBlending(false);
 	
 	if (gfx_hadFog) Gfx_SetFog(true);
-	gfx_rendering2D = false;
 }
 #endif