Move SSAO gInvProj to the CPU instead of GPU

Also make Mat4f.invert() return void instead of boolean to prevent confusion about trying to pass the result into shader uniforms.

core/src/main/java/com/seibel/distanthorizons/core/render/renderer/shaders/SSAORenderer.java

@@ -53,6 +53,7 @@ public class SSAORenderer
 	private static class SsaoShaderUniforms
 	{
 		public int gProjUniform;
+		public int gInvProjUniform;
 		public int gSampleRadUniform;
 		public int gFactorUniform;
 		public int gPowerUniform;
@@ -100,6 +101,7 @@ public class SSAORenderer
 		
 		// SSAO uniform setup
 		this.ssaoShaderUniforms.gProjUniform = this.ssaoShader.getUniformLocation("gProj");
+		this.ssaoShaderUniforms.gInvProjUniform = this.ssaoShader.getUniformLocation("gInvProj");
 		this.ssaoShaderUniforms.gSampleRadUniform = this.ssaoShader.getUniformLocation("gSampleRad");
 		this.ssaoShaderUniforms.gFactorUniform = this.ssaoShader.getUniformLocation("gFactor");
 		this.ssaoShaderUniforms.gPowerUniform = this.ssaoShader.getUniformLocation("gPower");
@@ -216,8 +218,13 @@ public class SSAORenderer
 				RenderUtil.getNearClipPlaneDistanceInBlocks(partialTicks),
 				(float) ((RenderUtil.getFarClipPlaneDistanceInBlocks() + LodUtil.REGION_WIDTH) * Math.sqrt(2)));
 		
+		Mat4f invertedPerspective = new Mat4f(perspective);
+		invertedPerspective.invert();
+		
+		
 		this.ssaoShader.bind();
 		this.ssaoShader.setUniform(this.ssaoShaderUniforms.gProjUniform, perspective);
+		this.ssaoShader.setUniform(this.ssaoShaderUniforms.gInvProjUniform, invertedPerspective);
 		this.ssaoShader.setUniform(this.ssaoShaderUniforms.gSampleRadUniform, 3.0f);
 		this.ssaoShader.setUniform(this.ssaoShaderUniforms.gFactorUniform, 0.8f);
 		this.ssaoShader.setUniform(this.ssaoShaderUniforms.gPowerUniform, 1.0f);

core/src/main/resources/shaders/ssao/ao.frag

@@ -9,6 +9,7 @@ uniform float gSampleRad;
 uniform float gFactor;
 uniform float gPower;
 uniform mat4 gProj;
+uniform mat4 gInvProj;
 
 const int MAX_KERNEL_SIZE = 128;
 const float INV_MAX_KERNEL_SIZE_F = 1.0 / float(MAX_KERNEL_SIZE);
@@ -25,7 +26,7 @@ vec3 calcViewPosition(vec2 coords) {
         1.0
     );
 
-    vec4 vs_pos = inverse(gProj) * ndc;
+    vec4 vs_pos = gInvProj * ndc;
     vs_pos.xyz = vs_pos.xyz / vs_pos.w;
     return vs_pos.xyz;
 }