Some improvements to android glitches

src/main/kotlin/ru/dbotthepony/mc/otm/client/render/GlitchRenderer.kt

@@ -8,6 +8,7 @@ import com.mojang.blaze3d.systems.RenderSystem
 import com.mojang.blaze3d.vertex.BufferBuilder
 import com.mojang.blaze3d.vertex.BufferUploader
 import com.mojang.blaze3d.vertex.DefaultVertexFormat
+import com.mojang.blaze3d.vertex.VertexBuffer
 import com.mojang.blaze3d.vertex.VertexFormat
 import com.mojang.math.Matrix4f
 import it.unimi.dsi.fastutil.ints.Int2ObjectArrayMap
@@ -299,6 +300,10 @@ object GlitchRenderer {
 		BufferUploader.drawWithShader(builder.end())
 	}
 
+	private val colorGlitchVertexBuffer by lazy {
+		VertexBuffer()
+	}
+
 	private var colorGlitchBuff = arrayOfNulls<VideoGlitchType>(0)
 	private var colorGlitchWidth = 0
 	private var colorGlitchHeight = 0
@@ -334,23 +339,53 @@ object GlitchRenderer {
 
 		for (xBlock in 0 .. colorGlitchWidth)
 			for (yBlock in 0 .. colorGlitchHeight)
-				if (colorGlitchChanceMultiplier(xBlock, yBlock) < 0.99f && random.nextFloat() > colorGlitchChanceMultiplier(xBlock, yBlock) * 0.999f)
+				if (colorGlitchChanceMultiplier(xBlock, yBlock) < 0.97f && random.nextFloat() > colorGlitchChanceMultiplier(xBlock, yBlock) * 0.999f)
 					colorGlitchBuff[xBlock + yBlock * colorGlitchWidth] = selectGlitch().let { it[random.nextInt(0, it.size)] }
 
 		for (xBlock in 0 .. colorGlitchWidth)
 			for (yBlock in 0 .. colorGlitchHeight)
-				if (colorGlitchChanceMultiplier(xBlock, yBlock) < 0.99f && random.nextFloat() > colorGlitchChanceMultiplier(xBlock, yBlock) * 0.9999f)
+				if (colorGlitchChanceMultiplier(xBlock, yBlock) < 0.97f && random.nextFloat() > colorGlitchChanceMultiplier(xBlock, yBlock) * 0.9999f)
 					putMacroGlitch(xBlock, yBlock, random.nextInt(1, 5), random.nextInt(1, 5), selectGlitchQuad().let { it[random.nextInt(0, it.size)] })
 
 		for (xBlock in 0 .. colorGlitchWidth)
 			for (yBlock in 0 .. colorGlitchHeight)
-				if (colorGlitchChanceMultiplier(xBlock, yBlock) < 0.99f && random.nextFloat() > colorGlitchChanceMultiplier(xBlock, yBlock) * 0.99999f)
+				if (colorGlitchChanceMultiplier(xBlock, yBlock) < 0.97f && random.nextFloat() > colorGlitchChanceMultiplier(xBlock, yBlock) * 0.99999f)
 					putMacroGlitch(xBlock, yBlock, random.nextInt(1, 9), random.nextInt(1, 9), selectGlitchQuad().let { it[random.nextInt(0, it.size)] })
 
 		for (xBlock in 0 .. colorGlitchWidth)
 			for (yBlock in 0 .. colorGlitchHeight)
-				if (colorGlitchChanceMultiplier(xBlock, yBlock) < 0.99f && random.nextFloat() > colorGlitchChanceMultiplier(xBlock, yBlock) * 0.999999f)
+				if (colorGlitchChanceMultiplier(xBlock, yBlock) < 0.97f && random.nextFloat() > colorGlitchChanceMultiplier(xBlock, yBlock) * 0.999999f)
 					putMacroGlitch(xBlock, yBlock, random.nextInt(1, 14), random.nextInt(1, 14), selectGlitchQuad().let { it[random.nextInt(0, it.size)] })
+
+		val blockStepWidth = (GLITCH_BLOCK_SIZE / glitchBuffer.width) * 2.0
+		val blockStepHeight = (GLITCH_BLOCK_SIZE / glitchBuffer.height) * 2.0
+
+		val blockStepWidthUV = GLITCH_BLOCK_SIZE / glitchBuffer.width
+		val blockStepHeightUV = GLITCH_BLOCK_SIZE / glitchBuffer.height
+
+		val builder = tesselator.builder
+
+		builder.begin(VertexFormat.Mode.TRIANGLES, DefaultVertexFormat.POSITION_TEX_COLOR)
+
+		for (xBlock in 0 .. colorGlitchWidth) {
+			for (yBlock in 0 .. colorGlitchHeight) {
+				colorGlitchBuff[xBlock + yBlock * colorGlitchWidth]?.upload(
+					builder = builder,
+					x = -1.0 + xBlock * blockStepWidth,
+					y = -1.0 + yBlock * blockStepHeight,
+					width = blockStepWidth,
+					height = blockStepHeight,
+					u0 = xBlock * blockStepWidthUV,
+					v0 = yBlock * blockStepHeightUV,
+					u1 = (xBlock + 1) * blockStepWidthUV,
+					v1 = (yBlock + 1) * blockStepHeightUV,
+				)
+			}
+		}
+
+		val colorGlitchBuffer = builder.end()
+		colorGlitchVertexBuffer.bind()
+		colorGlitchVertexBuffer.upload(colorGlitchBuffer)
 	}
 
 	private fun makeGlitch() {
@@ -384,14 +419,6 @@ object GlitchRenderer {
 			return
 		}
 
-		if (System.nanoTime() - lastGlitch >= nextGlitch) {
-			makeGlitch()
-		}
-
-		if (System.nanoTime() - lastEncodingGlitch >= nextEncodingGlitch) {
-			makeColorGlitch()
-		}
-
 		val glitchBuffer = glitchBuffer
 		val projection = RenderSystem.getProjectionMatrix()
 		RenderSystem.setProjectionMatrix(Matrix4f().also { it.setIdentity() })
@@ -407,14 +434,21 @@ object GlitchRenderer {
 		RenderSystem.disableDepthTest()
 		RenderSystem.enableBlend()
 		RenderSystem.enableTexture()
-		RenderSystem.clearColor(0f, 0f, 0f, 1f)
 
 		if (glitchBuffer.width != minecraft.window.width || glitchBuffer.height != minecraft.window.height) {
 			glitchBuffer.resize(minecraft.window.width, minecraft.window.height, Minecraft.ON_OSX)
+		}
+
 		glitchBuffer.bindWrite(true)
-		} else {
+		RenderSystem.clearColor(0f, 0f, 0f, 1f)
-			glitchBuffer.bindWrite(true)
 		RenderSystem.clear(GlConst.GL_COLOR_BUFFER_BIT, Minecraft.ON_OSX)
+
+		if (System.nanoTime() - lastGlitch >= nextGlitch) {
+			makeGlitch()
+		}
+
+		if (System.nanoTime() - lastEncodingGlitch >= nextEncodingGlitch) {
+			makeColorGlitch()
 		}
 
 		// distort colors by sampling main frame buffer (raw stage)
@@ -451,42 +485,10 @@ object GlitchRenderer {
 		drawVHSLineGap(((-System.currentTimeMillis() - glitchBuffer.height / 3) % glitchBuffer.height).toDouble().absoluteValue, glitchBuffer.height * 0.07)
 
 		// color encoding errors (encoder/transmission glitch)
-		val blocksWidth = ceil(glitchBuffer.width / GLITCH_BLOCK_SIZE).toInt()
-		val blocksHeight = ceil(glitchBuffer.height / GLITCH_BLOCK_SIZE).toInt()
-
-		if (colorGlitchWidth != blocksWidth || colorGlitchHeight != blocksHeight) {
-			makeColorGlitch()
-		}
-
-		val blockStepWidth = (GLITCH_BLOCK_SIZE / glitchBuffer.width) * 2.0
-		val blockStepHeight = (GLITCH_BLOCK_SIZE / glitchBuffer.height) * 2.0
-
-		val blockStepWidthUV = GLITCH_BLOCK_SIZE / glitchBuffer.width
-		val blockStepHeightUV = GLITCH_BLOCK_SIZE / glitchBuffer.height
-
-		val builder = tesselator.builder
-
-		builder.begin(VertexFormat.Mode.TRIANGLES, DefaultVertexFormat.POSITION_TEX_COLOR)
-
-		for (xBlock in 0 .. blocksWidth) {
-			for (yBlock in 0 .. blocksHeight) {
-				colorGlitchBuff[xBlock + yBlock * blocksWidth]?.upload(
-					builder = builder,
-					x = -1.0 + xBlock * blockStepWidth,
-					y = -1.0 + yBlock * blockStepHeight,
-					width = blockStepWidth,
-					height = blockStepHeight,
-					u0 = xBlock * blockStepWidthUV,
-					v0 = yBlock * blockStepHeightUV,
-					u1 = (xBlock + 1) * blockStepWidthUV,
-					v1 = (yBlock + 1) * blockStepHeightUV,
-				)
-			}
-		}
-
 		RenderSystem.setShaderColor(1f, 1f, 1f, 1f)
 		RenderSystem.setShader(GameRenderer::getPositionTexColorShader)
-		BufferUploader.drawWithShader(builder.end())
+		colorGlitchVertexBuffer.bind()
+		colorGlitchVertexBuffer.drawWithShader(Matrix4f().also { it.setIdentity() }, Matrix4f().also { it.setIdentity() }, GameRenderer.getPositionTexColorShader()!!)
 
 		// upload final result to main frame buffer
 		minecraft.mainRenderTarget.bindWrite(true)