Some water-related bug fixes:

- Underwater tiles will be tested against the frustum with a bounding
box including the water surface, so the water gets drawn even if the
terrain is off-screen.
- Transparent objects (e.g. trees) should now interact with water
properly. I did this by rendering them twice, first before the water, so
it overlaps the underwater pieces, then after, so the above-water pieces
overlap the water (the water now writes Z as well as colour to allow
this). Before, only the first pass was done, so the tops of trees were
covered by water. There might be more efficient ways of doing this - the
best could be for the transparent objects to be drawn with a shader that
always either discards a pixel or writes alpha of 1.0 instead of using
2-pass depth write then colour write.

This was SVN commit r3904.

source/graphics/GameView.cpp

@@ -287,7 +287,15 @@ void CGameView::RenderTerrain(CTerrain *pTerrain)
 	for (uint j=0; j<patchesPerSide; j++) {
 		for (uint i=0; i<patchesPerSide; i++) {
 			CPatch* patch=pTerrain->GetPatch(i,j);
-			if (frustum.IsBoxVisible (CVector3D(0,0,0),patch->GetBounds())) {
+
+			// If the patch is underwater, calculate a bounding box that also contains the water plane
+			CBound bounds = patch->GetBounds();
+			float waterHeight = g_Renderer.GetWaterManager()->m_WaterHeight + 0.001f;
+			if(bounds[1].Y < waterHeight) {
+				bounds[1].Y = waterHeight;
+			}
+			
+			if (frustum.IsBoxVisible (CVector3D(0,0,0), bounds)) {
 				g_Renderer.Submit(patch);
 			}
 		}

source/renderer/Renderer.cpp

@@ -1176,7 +1176,7 @@ void CRenderer::FlushFrame()
 
 	oglCheck();
 
-	if(m_Options.m_FancyWater)
+	if(m_WaterManager->m_RenderWater && m_Options.m_FancyWater)
 	{
 		// render reflected and refracted scenes, then re-clear the screen
 		RenderReflections();
@@ -1208,19 +1208,22 @@ void CRenderer::FlushFrame()
 	RenderModels();
 	oglCheck();
 
-	// call on the transparency renderer to render all the transparent stuff
+	// render transparent stuff
 	MICROLOG(L"render transparent");
 	RenderTransparentModels();
 	oglCheck();
 
-	// render water (note: we're assuming there's no transparent stuff over water...
-	// we could also do this above render transparent if we assume there's no transparent
-	// stuff underwater)
+	// render water
 	if (m_WaterManager->m_RenderWater)
 	{
 		MICROLOG(L"render water");
 		m->terrainRenderer->RenderWater();
 		oglCheck();
+
+		// render transparent stuff again, so it can overlap the water
+		MICROLOG(L"render transparent 2");
+		RenderTransparentModels();
+		oglCheck();
 	}
 
 	// Clean up texture blend mode so particles and other things render OK 

source/renderer/TerrainRenderer.cpp

@@ -391,7 +391,6 @@ void TerrainRenderer::RenderWater()
 	if(fancy && !m->fancyWaterShader)
 	{
 		m->fancyWaterShader = ogl_program_load( "shaders/water_high.xml" );
-		//debug_printf("Loaded the water shader!!\n");
 	}
 
 	//(Crappy) fresnel effect
@@ -409,7 +408,8 @@ void TerrainRenderer::RenderWater()
 	
 	glEnable(GL_BLEND);
 	glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
-	glDepthMask(GL_FALSE);
+	glEnable(GL_DEPTH_TEST);
+	glDepthFunc(GL_LEQUAL);
 
 	double time = WaterMgr->m_WaterTexTimer;
 
@@ -599,7 +599,6 @@ void TerrainRenderer::RenderWater()
 	}
 
 	glMatrixMode(GL_MODELVIEW);
-	glDepthMask(GL_TRUE);
 	glDisable(GL_BLEND);
 	glDisable(GL_TEXTURE_2D);
 }

source/renderer/TransparencyRenderer.cpp

@@ -546,6 +546,9 @@ u32 TransparentRenderModifier::BeginPass(uint pass)
 	{
 		// First pass: Put down Z for opaque parts of the model,
 		// don't touch the color buffer.
+
+		glDepthMask(1);
+
 		glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE);
 		glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_REPLACE);
 		glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_CONSTANT);