From 8f20c78ed1bc0a2bdfebbe34e42676afce223372 Mon Sep 17 00:00:00 2001
From: Quentin Bazin <quent42340@gmail.com>
Date: Thu, 26 Oct 2023 23:37:51 +0200
Subject: [PATCH] [ChunkRenderer] Now using 'u_mipLevel' uniform to specify max
 mip level.

---
 resources/shaders/game.fs.sc             |  3 ++-
 source/client/graphics/ChunkRenderer.cpp | 18 +++++++++++++-----
 source/client/graphics/ChunkRenderer.hpp |  1 +
 3 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/resources/shaders/game.fs.sc b/resources/shaders/game.fs.sc
index 648d0414..9dc53536 100644
--- a/resources/shaders/game.fs.sc
+++ b/resources/shaders/game.fs.sc
@@ -13,6 +13,7 @@ uniform vec4 u_renderDistance;
 uniform vec4 u_fogColor;
 uniform vec4 u_skyColor;
 uniform vec4 u_sunlightIntensity;
+uniform vec4 u_mipLevel;
 
 // Get light color
 vec4 light(vec4 position, vec4 normal, vec4 color, vec3 lightColor, vec4 lightPosition, float ambientIntensity, float diffuseIntensity) {
@@ -50,7 +51,7 @@ void main() {
 	// Get current pixel color and apply multiplier on grayscale textures
 	vec4 color = v_color0;
 	if (v_texcoord0.x > -0.99 && v_texcoord0.y > -0.99) {
-		color = texture2D(u_tex, v_texcoord0);
+		color = texture2DLod(u_tex, v_texcoord0, clamp(mix(u_mipLevel.x, u_mipLevel.y, v_dist / u_renderDistance.x), u_mipLevel.x, u_mipLevel.y));
 		if (blockFace > -1 && color.r == color.g && color.g == color.b) {
 			color *= v_color0;
 		}
diff --git a/source/client/graphics/ChunkRenderer.cpp b/source/client/graphics/ChunkRenderer.cpp
index 66d6f532..61968052 100644
--- a/source/client/graphics/ChunkRenderer.cpp
+++ b/source/client/graphics/ChunkRenderer.cpp
@@ -36,9 +36,15 @@
 ChunkRenderer::ChunkRenderer(const TextureAtlas &textureAtlas) : m_textureAtlas(textureAtlas) {
 	m_renderDistance = bgfx::createUniform("u_renderDistance", bgfx::UniformType::Vec4);
 	m_fogColor = bgfx::createUniform("u_fogColor", bgfx::UniformType::Vec4);
+	m_mipLevel = bgfx::createUniform("u_mipLevel", bgfx::UniformType::Vec4);
 }
 
 ChunkRenderer::~ChunkRenderer() {
+	if (bgfx::isValid(m_mipLevel)) {
+		bgfx::destroy(m_mipLevel);
+		m_mipLevel.idx = bgfx::kInvalidHandle;
+	}
+
 	if (bgfx::isValid(m_fogColor)) {
 		bgfx::destroy(m_fogColor);
 		m_fogColor.idx = bgfx::kInvalidHandle;
@@ -306,11 +312,11 @@ void ChunkRenderer::drawChunks(RenderTarget &target, RenderStates states, const
 	}
 
 	for (u8 layer = 0 ; layer < ChunkMeshLayer::Count ; ++layer) {
-#ifdef OM_NOT_IMPLEMENTED_GL_TEXTURE
-		// Disable mipmaps for specific layers
-		glCheck(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL,
-			(layer == ChunkMeshLayer::NoMipMap || layer == ChunkMeshLayer::Flora) ? 0 : Config::mipmapLevels));
-#endif // OM_NOT_IMPLEMENTED_GL_TEXTURE
+		float mipLevel[4] = {0.f,
+			(layer == ChunkMeshLayer::NoMipMap || layer == ChunkMeshLayer::Flora)
+				? 0.f : (float)Config::mipmapLevels,
+			0.f, 0.f
+		};
 
 		if (layer == ChunkMeshLayer::Flora || layer == ChunkMeshLayer::Liquid)
 			states.isCullFaceEnabled = false;
@@ -321,6 +327,8 @@ void ChunkRenderer::drawChunks(RenderTarget &target, RenderStates states, const
 			std::size_t verticesCount = std::get<0>(it)->getVerticesCount(layer);
 			if (verticesCount == 0) continue;
 
+			bgfx::setUniform(m_mipLevel, mipLevel);
+
 			target.beginDrawing(states);
 
 			bgfx::setTransform(std::get<1>(it).getRawMatrix());
diff --git a/source/client/graphics/ChunkRenderer.hpp b/source/client/graphics/ChunkRenderer.hpp
index 2f45e8fe..9f619fa1 100644
--- a/source/client/graphics/ChunkRenderer.hpp
+++ b/source/client/graphics/ChunkRenderer.hpp
@@ -62,6 +62,7 @@ class ChunkRenderer {
 
 		bgfx::UniformHandle m_renderDistance = BGFX_INVALID_HANDLE;
 		bgfx::UniformHandle m_fogColor = BGFX_INVALID_HANDLE;
+		bgfx::UniformHandle m_mipLevel = BGFX_INVALID_HANDLE;
 };
 
 #endif // CHUNKRENDERER_HPP_