From 37f10877836df47b1becbb61bac181142f0e0cb9 Mon Sep 17 00:00:00 2001
From: Philip Rebohle <philip.rebohle@tu-dortmund.de>
Date: Mon, 6 May 2019 00:04:47 +0200
Subject: [PATCH] [dxvk] Add API for specialization constants

---
 src/dxvk/dxvk_context.cpp  | 10 ++++++++++
 src/dxvk/dxvk_context.h    | 13 +++++++++++++
 src/dxvk/dxvk_graphics.cpp |  3 +++
 src/dxvk/dxvk_graphics.h   |  2 ++
 src/dxvk/dxvk_limits.h     |  1 +
 src/dxvk/dxvk_shader.h     |  3 ++-
 src/dxvk/dxvk_spec_const.h | 37 +++++++++++++++++++++++++++++++++++++
 7 files changed, 68 insertions(+), 1 deletion(-)

diff --git a/src/dxvk/dxvk_context.cpp b/src/dxvk/dxvk_context.cpp
index ebf192fbb..87ce23cb9 100644
--- a/src/dxvk/dxvk_context.cpp
+++ b/src/dxvk/dxvk_context.cpp
@@ -2142,6 +2142,16 @@ namespace dxvk {
     
     m_flags.set(DxvkContextFlag::GpDirtyPipelineState);
   }
+
+
+  void DxvkContext::setSpecConstant(
+          uint32_t            index,
+          uint32_t            value) {
+    if (m_state.gp.state.scSpecConstants[index] != value) {
+      m_state.gp.state.scSpecConstants[index] = value;
+      m_flags.set(DxvkContextFlag::GpDirtyPipelineState);
+    }
+  }
   
   
   void DxvkContext::setPredicate(
diff --git a/src/dxvk/dxvk_context.h b/src/dxvk/dxvk_context.h
index 043007afb..b5636f7b3 100644
--- a/src/dxvk/dxvk_context.h
+++ b/src/dxvk/dxvk_context.h
@@ -856,6 +856,19 @@ namespace dxvk {
             uint32_t            attachment,
       const DxvkBlendMode&      blendMode);
     
+    /**
+     * \brief Sets specialization constants
+     * 
+     * Replaces current specialization constants with
+     * the given list of constant entries. The specId
+     * in the shader can be computed with \c getSpecId.
+     * \param [in] index Constant index
+     * \param [in] value Constant value
+     */
+    void setSpecConstant(
+            uint32_t            index,
+            uint32_t            value);
+    
     /**
      * \brief Sets predicate
      *
diff --git a/src/dxvk/dxvk_graphics.cpp b/src/dxvk/dxvk_graphics.cpp
index d5086385a..1bb4e46bf 100644
--- a/src/dxvk/dxvk_graphics.cpp
+++ b/src/dxvk/dxvk_graphics.cpp
@@ -205,6 +205,9 @@ namespace dxvk {
         specData.set(specId + 3, util::getComponentIndex(state.omComponentMapping[i].a, 3), 3u);
       }
     }
+
+    for (uint32_t i = 0; i < MaxNumSpecConstants; i++)
+      specData.set(getSpecId(i), state.scSpecConstants[i], 0u);
     
     VkSpecializationInfo specInfo = specData.getSpecInfo();
     
diff --git a/src/dxvk/dxvk_graphics.h b/src/dxvk/dxvk_graphics.h
index 5ee841c03..e56869505 100644
--- a/src/dxvk/dxvk_graphics.h
+++ b/src/dxvk/dxvk_graphics.h
@@ -109,6 +109,8 @@ namespace dxvk {
     VkLogicOp                           omLogicOp;
     VkPipelineColorBlendAttachmentState omBlendAttachments[MaxNumRenderTargets];
     VkComponentMapping                  omComponentMapping[MaxNumRenderTargets];
+
+    uint32_t                            scSpecConstants[MaxNumSpecConstants];
   };
   
   
diff --git a/src/dxvk/dxvk_limits.h b/src/dxvk/dxvk_limits.h
index 183b4492b..f983c97e6 100644
--- a/src/dxvk/dxvk_limits.h
+++ b/src/dxvk/dxvk_limits.h
@@ -15,6 +15,7 @@ namespace dxvk {
     MaxNumActiveBindings        =   128,
     MaxNumQueuedCommandBuffers  =     8,
     MaxNumQueryCountPerPool     =   128,
+    MaxNumSpecConstants         =     8,
     MaxUniformBufferSize        = 65536,
     MaxVertexBindingStride      =  2048,
     MaxPushConstantSize         =   128,
diff --git a/src/dxvk/dxvk_shader.h b/src/dxvk/dxvk_shader.h
index 640d12793..fb38e2ba4 100644
--- a/src/dxvk/dxvk_shader.h
+++ b/src/dxvk/dxvk_shader.h
@@ -30,7 +30,8 @@ namespace dxvk {
 
     // Specialization constants for pipeline state
     SpecConstantRangeStart      = ColorComponentMappings + MaxNumRenderTargets * 4,
-    RasterizerSampleCount       = SpecConstantRangeStart,
+    RasterizerSampleCount       = SpecConstantRangeStart + 0,
+    FirstPipelineConstant
   };
   
   
diff --git a/src/dxvk/dxvk_spec_const.h b/src/dxvk/dxvk_spec_const.h
index 8c0f42f44..df4f041cb 100644
--- a/src/dxvk/dxvk_spec_const.h
+++ b/src/dxvk/dxvk_spec_const.h
@@ -4,6 +4,18 @@
 #include "dxvk_shader.h"
 
 namespace dxvk {
+
+  /**
+   * \briefS Specialization constant entry
+   * 
+   * Used to pass a list of user-defined
+   * specialization constants to shaders.
+   */
+  struct DxvkSpecConstant {
+    uint32_t specId;
+    uint32_t value;
+  };
+
   
   /**
    * \brief Specialization constant info
@@ -36,6 +48,18 @@ namespace dxvk {
         setAsUint32(specId, uint32_t(value));
     }
 
+    /**
+     * \brief Sets specialization constant value
+     *
+     * Always passes the constant value to the driver.
+     * \param [in] specId Specialization constant ID
+     * \param [in] value Specialization constant value
+     */
+    template<typename T>
+    void set(uint32_t specId, T value) {
+      setAsUint32(specId, uint32_t(value));
+    }
+
     /**
      * \brief Generates specialization info structure
      * \returns Specialization info for shader module
@@ -50,5 +74,18 @@ namespace dxvk {
     void setAsUint32(uint32_t specId, uint32_t value);
 
   };
+
+
+  /**
+   * \brief Computes specialization constant ID
+   * 
+   * Computest the specId to use within shaders
+   * for a given pipeline specialization constant.
+   * \param [in] index Spec constant index
+   * \returns Specialization constant ID
+   */
+  inline uint32_t getSpecId(uint32_t index) {
+    return uint32_t(DxvkSpecConstantId::FirstPipelineConstant) + index;
+  }
   
 }
\ No newline at end of file