From e3b660121cf51a1be2afbf31cb676a19eb714a2c Mon Sep 17 00:00:00 2001
From: Ravbug <ravbug@noreply.users.github.com>
Date: Thu, 4 Jul 2024 14:45:33 -0700
Subject: [PATCH] Fix the indices by reading from a buffer

---
 09-BindlessTexturing/bindlesstexturing.cpp | 29 +++++++++++++++++++---
 09-BindlessTexturing/btex.frag             |  2 +-
 09-BindlessTexturing/btex.vert             |  8 ++++--
 3 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/09-BindlessTexturing/bindlesstexturing.cpp b/09-BindlessTexturing/bindlesstexturing.cpp
index 04d63e1..1af79c2 100644
--- a/09-BindlessTexturing/bindlesstexturing.cpp
+++ b/09-BindlessTexturing/bindlesstexturing.cpp
@@ -19,7 +19,7 @@ struct BindlessTexturing : public ExampleFramework {
     } comp_ubo;
 
     RGLCommandBufferPtr commandBuffer;
-    RGLBufferPtr vertexBuffer, indexBuffer;
+    RGLBufferPtr vertexBuffer, indexBuffer, instanceDataBuffer;
     RGLTexturePtr depthTexture, tx1, tx2, tx3;
     RGLSamplerPtr sampler;
     RGLRenderPipelinePtr renderPipeline;
@@ -64,12 +64,19 @@ struct BindlessTexturing : public ExampleFramework {
                     .type = RGL::BindingType::Sampler,
                     .stageFlags = RGL::BindingVisibility::Fragment,
                 },
-                {
+                 {
                     .binding = 1,
                     .count = 512,
+                    .type = RGL::BindingType::StorageBuffer,
+                    .stageFlags = RGL::BindingVisibility::Vertex,
+                },
+                {
+                    .binding = 2,
+                    .count = 512,
                     .type = RGL::BindingType::SampledImage,
                     .stageFlags = RGL::BindingVisibility::Fragment,
                 },
+                
             },
             .constants = {{ ubo, 0, RGL::StageVisibility::Vertex}}
             });
@@ -188,6 +195,20 @@ struct BindlessTexturing : public ExampleFramework {
         loadTx("tx29.png",tx1);
         loadTx("tx34.png",tx2);
         loadTx("tx39.png",tx3);
+
+        uint32_t indices[] = {
+            tx1->GetDefaultView().texture.dx.srvIDX,
+            tx2->GetDefaultView().texture.dx.srvIDX,
+            tx3->GetDefaultView().texture.dx.srvIDX
+        };
+
+        instanceDataBuffer = device->CreateBuffer({
+            {.StorageBuffer = true},
+            sizeof(decltype(indices[0])),
+            indices,
+            RGL::BufferAccess::Private
+            });
+        instanceDataBuffer->SetBufferData(indices);
        
     }
 
@@ -224,7 +245,8 @@ struct BindlessTexturing : public ExampleFramework {
         commandBuffer->SetVertexBuffer(vertexBuffer);
         commandBuffer->SetIndexBuffer(indexBuffer);
         commandBuffer->SetFragmentSampler(sampler,0);
-        commandBuffer->SetFragmentTexture(heapStart, 1);        // expose all the textures
+        commandBuffer->SetFragmentTexture(heapStart, 2);        // expose all the textures
+        commandBuffer->BindBuffer(instanceDataBuffer, 1);
         commandBuffer->DrawIndexed(std::size(BasicObjects::Quad::indices), {.nInstances = 3});
 
         commandBuffer->EndRendering();
@@ -240,6 +262,7 @@ struct BindlessTexturing : public ExampleFramework {
     }
 
     void sampleshutdown() final {
+        instanceDataBuffer.reset();
         tx1.reset();
         tx2.reset();
         tx3.reset();
diff --git a/09-BindlessTexturing/btex.frag b/09-BindlessTexturing/btex.frag
index be6445d..8716d64 100644
--- a/09-BindlessTexturing/btex.frag
+++ b/09-BindlessTexturing/btex.frag
@@ -1,7 +1,7 @@
 #extension GL_EXT_nonuniform_qualifier : enable
 
 layout(binding = 0) uniform sampler g_sampler;
-layout(binding = 1) uniform texture2D textures[];
+layout(binding = 2) uniform texture2D textures[];
 
 layout(location = 0) in vec2 uv;
 layout(location = 1) in flat uint instance;
diff --git a/09-BindlessTexturing/btex.vert b/09-BindlessTexturing/btex.vert
index d5791d9..35621b4 100644
--- a/09-BindlessTexturing/btex.vert
+++ b/09-BindlessTexturing/btex.vert
@@ -9,6 +9,10 @@ layout(location = 1) in vec2 inUV;
 layout(location = 0) out vec2 outUV;
 layout(location = 1) out flat uint instance;
 
+layout (binding = 1) readonly buffer bindlessSSBO{
+    uint indices[];
+};
+
 vec3 positions[] = {
     vec3(-3,0,0),
     vec3(0,0,0),
@@ -17,9 +21,9 @@ vec3 positions[] = {
 
 void main(){
 
-    instance = gl_InstanceID;
+    instance = indices[gl_InstanceID];
 
-    vec3 pos = vec3(inPosition, 0) + positions[gl_InstanceID];
+    vec3 pos = vec3(inPosition, 0) + positions[instance];
 
     gl_Position = ubo.viewProj * vec4(pos, 1);
     outUV = inUV;