Make shader based clouds work with iris shaderpacks, and port optimizations from #1685 (#1793)

* Make shader based clouds work with iris shaderpacks, and port optimizations from #1685

Co-Authored-By: Eclipse-Sol <Eclipse-Sol@users.noreply.github.com>

* Yeet GL_QUADS

* Optimize a little more

---------

Co-authored-by: Eclipse-Sol <Eclipse-Sol@users.noreply.github.com>
Co-authored-by: Logan Phillips <phillips-l@outlook.com>

src/main/java/net/coderbot/iris/gl/state/StateUpdateNotifiers.java

@@ -11,6 +11,7 @@ public class StateUpdateNotifiers {
     public static ValueUpdateNotifier alphaFuncNotifier;
     public static ValueUpdateNotifier alphaTestNotifier;
 	public static ValueUpdateNotifier blendFuncNotifier;
+	public static ValueUpdateNotifier colorModulatorNotifier;
 	public static ValueUpdateNotifier bindTextureNotifier;
 	public static ValueUpdateNotifier normalTextureChangeNotifier;
 	public static ValueUpdateNotifier specularTextureChangeNotifier;

src/main/java/net/coderbot/iris/pipeline/transform/AttributeTransformer.java

@@ -34,7 +34,7 @@ class AttributeTransformer {
 			transformer.injectVariable("layout(location = 4) in vec3 iris_Normal;");
 
 			transformer.rename("gl_Vertex", "iris_Vertex");
-			transformer.rename("gl_Color", "iris_Color");
+			transformer.replaceExpression("gl_Color", "(iris_Color * iris_ColorModulator)");
 			transformer.rename("gl_Normal", "iris_Normal");
 
 			// ftransform() = gl_ModelViewProjectionMatrix * gl_Vertex

src/main/java/net/coderbot/iris/pipeline/transform/CeleritasTransformer.java

@@ -34,6 +34,7 @@ class CeleritasTransformer {
         transformer.injectFunction(
             "void _celeritas_init() { " +
             "_vert_init(); " +
+            "_vert_color = _vert_color * iris_ColorModulator; " +
             "iris_LightTexCoord = vec4(vec2(_vert_tex_light_coord), 0.0, 1.0); }");
         transformer.prependMain("_celeritas_init();");
         transformShared(transformer, parameters);

src/main/java/net/coderbot/iris/pipeline/transform/CommonTransformer.java

@@ -20,9 +20,10 @@ public class CommonTransformer {
 		}
 
 		if (parameters.type == ShaderType.VERTEX) {
+			root.injectVariable("uniform vec4 iris_ColorModulator;");
 			root.injectVariable("out vec4 iris_FrontColor;");
 			root.rename("gl_FrontColor", "iris_FrontColor");
-			root.prependMain("iris_FrontColor = vec4(1.0);");
+			root.prependMain("iris_FrontColor = iris_ColorModulator;");
 		} else if (parameters.type == ShaderType.FRAGMENT) {
 			root.injectVariable("in vec4 iris_FrontColor;");
 			root.rename("gl_Color", "iris_FrontColor");

src/main/java/net/coderbot/iris/pipeline/transform/DHGenericTransformer.java

@@ -94,7 +94,7 @@ public class DHGenericTransformer {
                 + " float skyLight = (float(uSkyLight) + 0.5) / 16.0;"
                 + " _vert_tex_light_coord = vec2(blockLight, skyLight);"
                 + " dhMaterialId = aMaterial;"
-                + " _vert_color = iris_color;"
+                + " _vert_color = iris_color * iris_ColorModulator;"
                 + " }"
         );
         transformer.prependMain("_vert_init();");

src/main/java/net/coderbot/iris/pipeline/transform/DHTerrainTransformer.java

@@ -86,7 +86,7 @@ public class DHTerrainTransformer {
                 + " _vert_normal = irisNormals[int(irisExtra.y)];"
                 + " dhMaterialId = int(irisExtra.x);"
                 + " _vert_tex_light_coord = vec2((float(lights / 16u) + 0.5) / 16.0, (mod(float(lights), 16.0) + 0.5) / 16.0);"
-                + " _vert_color = iris_color;"
+                + " _vert_color = iris_color * iris_ColorModulator;"
                 + " }"
         );
         transformer.prependMain("_vert_init();");

src/main/java/net/coderbot/iris/shaderpack/loading/ProgramId.java

@@ -23,7 +23,7 @@ public enum ProgramId {
 	TexturedLit(ProgramGroup.Gbuffers, "textured_lit", Textured),
 	SkyBasic(ProgramGroup.Gbuffers, "skybasic", Basic),
 	SkyTextured(ProgramGroup.Gbuffers, "skytextured", Textured),
-	Clouds(ProgramGroup.Gbuffers, "clouds", Textured),
+	Clouds(ProgramGroup.Gbuffers, "clouds", Textured, null, new AlphaTestOverride(new AlphaTest(AlphaTestFunction.GREATER, 0.1F))),
 
 	Terrain(ProgramGroup.Gbuffers, "terrain", TexturedLit),
 	TerrainSolid(ProgramGroup.Gbuffers, "terrain_solid", Terrain),

src/main/java/net/coderbot/iris/uniforms/IrisExclusiveUniforms.java

@@ -2,6 +2,7 @@ package net.coderbot.iris.uniforms;
 
 import com.gtnewhorizons.angelica.compat.mojang.Camera;
 import com.gtnewhorizons.angelica.compat.mojang.GameModeUtil;
+import com.gtnewhorizons.angelica.render.CloudRenderer;
 import net.coderbot.iris.gl.uniform.UniformHolder;
 import net.coderbot.iris.gl.uniform.UniformUpdateFrequency;
 import net.minecraft.client.Minecraft;
@@ -40,6 +41,16 @@ public class IrisExclusiveUniforms {
 		uniforms.uniform3d(UniformUpdateFrequency.PER_FRAME, "eyePosition", IrisExclusiveUniforms::getEyePosition);
 		uniforms.uniform3d(UniformUpdateFrequency.PER_FRAME, "relativeEyePosition", IrisExclusiveUniforms::getRelativeEyePosition);
 		uniforms.uniform4f(UniformUpdateFrequency.PER_TICK, "lightningBoltPosition", IrisExclusiveUniforms::getLightningBoltPosition);
+		uniforms.uniform1f(UniformUpdateFrequency.PER_FRAME, "cloudTime", IrisExclusiveUniforms::getCloudTime);
+	}
+
+	private static float getCloudTime() {
+		final WorldClient level = Minecraft.getMinecraft().theWorld;
+		if (level == null) return 0f;
+		final long cycle = (long) CloudRenderer.getCloudTextureWidth() * 400L * CloudRenderer.getScaleMult();
+		final long t = level.getTotalWorldTime() % cycle;
+		final float partial = Minecraft.getMinecraft().timer.renderPartialTicks;
+		return (t + partial) * 0.03F;
 	}
 
 	private static float getThunderStrength() {

src/main/java/net/coderbot/iris/uniforms/IrisInternalUniforms.java

@@ -12,10 +12,19 @@ import static net.coderbot.iris.gl.uniform.UniformUpdateFrequency.PER_FRAME;
 
 public class IrisInternalUniforms {
     private static final Vector4f FOG_COLOR = new Vector4f();
+    private static final Vector4f COLOR_MODULATOR = new Vector4f(1f, 1f, 1f, 1f);
 
     private IrisInternalUniforms() {
     }
 
+    private static Vector4f getColorModulator() {
+        return COLOR_MODULATOR.set(
+            GLStateManager.getShaderColorR(),
+            GLStateManager.getShaderColorG(),
+            GLStateManager.getShaderColorB(),
+            GLStateManager.getShaderColorA());
+    }
+
     private static float getEffectiveAlphaRef() {
         if (!GLStateManager.getAlphaTest().isEnabled() || GLStateManager.getAlphaState().getFunction() == GL11.GL_ALWAYS) {
             return -1.0f;
@@ -44,5 +53,7 @@ public class IrisInternalUniforms {
             .uniform1f("iris_currentAlphaTest", IrisInternalUniforms::getEffectiveAlphaRef, StateUpdateNotifiers.alphaTestNotifier)
             .uniform1f("alphaTestRef", IrisInternalUniforms::getEffectiveAlphaRef, StateUpdateNotifiers.alphaTestNotifier)
             .uniform1i("iris_currentAlphaFunc", IrisInternalUniforms::getEffectiveAlphaFunc, StateUpdateNotifiers.alphaFuncNotifier);
+
+        uniforms.uniform4f("iris_ColorModulator", IrisInternalUniforms::getColorModulator, StateUpdateNotifiers.colorModulatorNotifier);
     }
 }