Add godbolt links for code snippets (#282)

Author: spencer-lunarg

chapters/high_level_shader_language_comparison.adoc

@@ -127,7 +127,7 @@ HLSL
 ----
 struct VSOutput
 {
-    // The SV_POSITION semantic declares the Pos member as the vertex output position 
+    // The SV_POSITION semantic declares the Pos member as the vertex output position
     float4 Pos : SV_POSITION;
 };
 
@@ -144,7 +144,7 @@ Reading the vertex index:
 GLSL:
 [source,glsl]
 ----
-void main() 
+void main()
 {
     // The vertex index is stored in the gl_VertexIndex built-in
     outUV = vec2((gl_VertexIndex << 1) & 2, gl_VertexIndex & 2);
@@ -254,7 +254,7 @@ Examples:
 [source,glsl]
 ----
 // Uniform buffer
-layout (set = 0, binding = 0) uniform UBO 
+layout (set = 0, binding = 0) uniform UBO
 {
     mat4 projection;
 } ubo;
@@ -990,20 +990,20 @@ These shader stages share several functions and built-ins
 | imageAtomicExchange | InterlockedExchange |
 | nonuniformEXT | NonUniformResourceIndex |
 | gl_BaryCoordEXT | SV_Barycentrics |
-| gl_BaryCoordNoPerspEXT | SV_Barycentrics with noperspective | 
+| gl_BaryCoordNoPerspEXT | SV_Barycentrics with noperspective |
 |====
 
 == Functions
 
 [NOTE]
 ====
 Most GLSL functions are also available in HLSL and vice-versa. This chapter lists functions with divergent names. Functions that have a 1:1 counterpart (e.g. `isNan`) aren't listed.
-==== 
+====
 
 [options="header"]
 |====
 | *GLSL* | *HLSL*
-| dFdx | ddx 
+| dFdx | ddx
 | dFdxCoarse | ddx_coarse
 | dFdxFine | ddx_fine
 | dFdy | ddy

chapters/hlsl.adoc

@@ -42,6 +42,7 @@ Similar to regular programming languages, HLSL and GLSL differ in their syntax.
 Here is the same shader written in both languages to give quick comparison on how they basically differ, including the aforementioned namespace that e.g. adds explicit locations:
 
 === GLSL
+link:https://godbolt.org/z/jcPofTK9j[Try Online]
 [source,glsl]
 ----
 #version 450
@@ -66,6 +67,7 @@ void main()
 ----
 
 === HLSL
+link:https://godbolt.org/z/Y4sd9anMY[Try Online]
 [source,hlsl]
 ----
 struct VSInput
@@ -93,7 +95,7 @@ VSOutput main(VSInput input, uint VertexIndex : SV_VertexID)
 {
 	VSOutput output = (VSOutput)0;
 	output.Color = input.Color * float(VertexIndex);
-	output.Position = mul(ubo.projectionMatrix, mul(ubo.viewMatrix, mul(ubo.modelMatrix, float4(input.Position.xyz, 1.0))));
+	output.Pos = mul(ubo.projectionMatrix, mul(ubo.viewMatrix, mul(ubo.modelMatrix, float4(input.Position.xyz, 1.0))));
 	return output;
 }
 ----
@@ -198,7 +200,7 @@ std::vector<LPCWSTR> arguments = {
 	// Shader target profile
 	L"-T", targetProfile,
 	// Compile to SPIRV
-	L"-spirv"				
+	L"-spirv"
 };
 
 // Compile shader

chapters/mapping_data_to_shaders.adoc

@@ -39,7 +39,7 @@ The only shader stage in core Vulkan that has an input attribute controlled by V
 
 Before calling `vkCreateGraphicsPipelines` a `VkPipelineVertexInputStateCreateInfo` struct will need to be filled out with a list of `VkVertexInputAttributeDescription` mappings to the shader.
 
-An example GLSL vertex shader:
+An example GLSL vertex shader (link:https://godbolt.org/z/x3b3ceTa6[Try Online]):
 
 [source,glsl]
 ----
@@ -55,12 +55,11 @@ There is only a single input attribute at location 0. This can also be seen in t
 
 [source,swift]
 ----
-                Name 18  "inPosition"
-                Decorate 18(inPosition) Location 0
+               OpDecorate %inPosition Location 0
 
-            17: TypePointer Input 16(fvec3)
-18(inPosition): 17(ptr) Variable Input
-            19: 16(fvec3) Load 18(inPosition)
+        %ptr = OpTypePointer Input %v3float
+ %inPosition = OpVariable %ptr Input
+         %20 = OpLoad %v3float %inPosition
 ----
 
 In this example, the following could be used for the `VkVertexInputAttributeDescription`:
@@ -115,7 +114,7 @@ In this example, there are the following 3 descriptor sets:
 
 image::{images}mapping_data_to_shaders_descriptor_1.png[mapping_data_to_shaders_descriptor_1.png]
 
-The GLSL of the shader:
+The GLSL of the shader (link:https://godbolt.org/z/oMz58a78T[Try Online]):
 
 [source,glsl]
 ----
@@ -140,23 +139,23 @@ The corresponding SPIR-V assembly:
 
 [source,swift]
 ----
-Decorate 19(myTextureSampler) DescriptorSet 0
-Decorate 19(myTextureSampler) Binding 0
+OpDecorate %myTextureSampler DescriptorSet 0
+OpDecorate %myTextureSampler Binding 0
 
-MemberDecorate 29(uniformBuffer0) 0 Offset 0
-Decorate 29(uniformBuffer0) Block
-Decorate 31(ubo_0) DescriptorSet 0
-Decorate 31(ubo_0) Binding 2
+OpMemberDecorate %uniformBuffer0 0 Offset 0
+OpDecorate %uniformBuffer0 Block
+OpDecorate %ubo_0 DescriptorSet 0
+OpDecorate %ubo_0 Binding 2
 
-MemberDecorate 38(uniformBuffer1) 0 Offset 0
-Decorate 38(uniformBuffer1) Block
-Decorate 40(ubo_1) DescriptorSet 0
-Decorate 40(ubo_1) Binding 3
+OpMemberDecorate %uniformBuffer1 0 Offset 0
+OpDecorate %uniformBuffer1 Block
+OpDecorate %ubo_1 DescriptorSet 0
+OpDecorate %ubo_1 Binding 3
 
-MemberDecorate 44(storageBuffer) 0 Offset 0
-Decorate 44(storageBuffer) BufferBlock
-Decorate 46(ssbo) DescriptorSet 2
-Decorate 46(ssbo) Binding 0
+OpMemberDecorate %storageBuffer 0 Offset 0
+OpDecorate %storageBuffer BufferBlock
+OpDecorate %ssbo DescriptorSet 2
+OpDecorate %ssbo Binding 0
 ----
 
 The binding of descriptors is done while recording the command buffer. The descriptors must be bound at the time of a draw/dispatch call. The following is some pseudo code to better represent this:
@@ -194,6 +193,8 @@ For GLSL, more information can be found in the link:https://registry.khronos.org
 
 `VK_DESCRIPTOR_TYPE_STORAGE_IMAGE`
 
+link:https://godbolt.org/z/7KPe11GPs[Try Online]
+
 [source,glsl]
 ----
 // VK_FORMAT_R32_UINT
@@ -219,6 +220,8 @@ OpDecorate %storageImage Binding 0
 
 `VK_DESCRIPTOR_TYPE_SAMPLER` and `VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE`
 
+link:https://godbolt.org/z/zbb3TW19x[Try Online]
+
 [source,glsl]
 ----
 layout(set = 0, binding = 0) uniform sampler samplerDescriptor;
@@ -262,6 +265,8 @@ OpDecorate %samplerDescriptor Binding 0
 On some implementations, it **may** be more efficient to sample from an image using a combination of sampler and sampled image that are stored together in the descriptor set in a combined descriptor.
 ====
 
+link:https://godbolt.org/z/aTrajsrY3[Try Online]
+
 [source,glsl]
 ----
 layout(set = 0, binding = 0) uniform sampler2D combinedImageSampler;
@@ -294,6 +299,8 @@ OpDecorate %combinedImageSampler Binding 0
 Uniform buffers can also have xref:{chapters}descriptor_dynamic_offset.adoc[dynamic offsets at bind time] (VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC)
 ====
 
+link:https://godbolt.org/z/qz6dcndxd[Try Online]
+
 [source,glsl]
 ----
 layout(set = 0, binding = 0) uniform uniformBuffer {
@@ -329,6 +336,8 @@ OpDecorate %ubo Binding 0
 Storage buffers can also have xref:{chapters}descriptor_dynamic_offset.adoc[dynamic offsets at bind time] (VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC)
 ====
 
+link:https://godbolt.org/z/hEfe8PhfY[Try Online]
+
 [source,glsl]
 ----
 layout(set = 0, binding = 0) buffer storageBuffer {
@@ -365,6 +374,8 @@ OpDecorate %ssbo Binding 0
 
 `VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER`
 
+link:https://godbolt.org/z/ob4T9d3E4[Try Online]
+
 [source,glsl]
 ----
 layout(set = 0, binding = 0) uniform textureBuffer uniformTexelBuffer;
@@ -389,6 +400,8 @@ OpDecorate %uniformTexelBuffer Binding 0
 
 `VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER`
 
+link:https://godbolt.org/z/zoeMxsKjq[Try Online]
+
 [source,glsl]
 ----
 // VK_FORMAT_R8G8B8A8_UINT
@@ -415,6 +428,8 @@ OpDecorate %storageTexelBuffer Binding 0
 
 `VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT`
 
+link:https://godbolt.org/z/aMncGWajG[Try Online]
+
 [source,glsl]
 ----
 layout (input_attachment_index = 0, set = 0, binding = 0) uniform subpassInput inputAttachment;
@@ -476,6 +491,8 @@ void main() {
 
 Using specialization constants, the decision can instead be made when calling `vkCreateGraphicsPipelines` to compile the shader. This means there only needs to be a single shader.
 
+link:https://godbolt.org/z/xnncjdf3z[Try Online]
+
 [source,glsl]
 ----
 #version 450
@@ -489,13 +506,13 @@ void main() {
 
 Resulting SPIR-V assembly:
 
-[source,spswiftirv]
+[source,swift]
 ----
-                      Decorate 9(outColor) Location 0
-                      Decorate 10(myColor) SpecId 0
+           OpDecorate %outColor Location 0
+           OpDecorate %myColor SpecId 0
 
-                      // 0x3f800000 as decimal which is 1.0 for a 32 bit float
-10(myColor): 6(float) SpecConstant 1065353216
+// 0x3f800000 as decimal which is 1.0 for a 32 bit float
+%myColor = OpSpecConstant %float 1065353216
 ----
 
 With specialization constants, the value is still a constant inside the shader, but for example, if another `VkPipeline` uses the same shader, but wants to set the `myColor` value to `0.5f`, it is possible to do so at runtime.

chapters/push_constants.adoc

@@ -35,7 +35,7 @@ A small bank of values writable via the API and accessible in shaders. Push cons
 
 From a shader perspective, push constant are similar to a uniform buffer. The spec provides details for the link:https://www.khronos.org/registry/vulkan/specs/1.3-extensions/html/vkspec.html#interfaces-resources-pushconst[push constant interface] between Vulkan and SPIR-V.
 
-A simple GLSL fragment shader example:
+A simple GLSL fragment shader example (link:https://godbolt.org/z/93WaYd8dE[Try Online]):
 
 [source,glsl]
 ----

chapters/shader_memory_layout.adoc

@@ -39,6 +39,8 @@ This extension allows the use of `std430` memory layout in UBOs. link:https://re
 
 One example of when the `uniformBufferStandardLayout` feature is needed is when an application doesn't want the array stride for a UBO to be restricted to `extended alignment`
 
+(link:https://godbolt.org/z/j11d58hcs[Try Online])
+
 [source,glsl]
 ----
 layout(std140, binding = 0) uniform ubo140 {
@@ -140,6 +142,8 @@ The following are some GLSL to SPIR-V examples to help better understand the dif
 
 === Alignment Example 1
 
+(link:https://godbolt.org/z/9rWKEdf1W[Try Online])
+
 [source,glsl]
 ----
 layout(binding = 0) buffer block {
@@ -165,6 +169,8 @@ OpMemberDecorate %block 1 Offset 32
 
 === Alignment Example 2
 
+(link:https://godbolt.org/z/YMr6P749b[Try Online])
+
 [source,glsl]
 ----
 layout(binding = 0) buffer block {
@@ -191,6 +197,8 @@ OpMemberDecorate %block 2 Offset 12
 
 === Alignment Example 3
 
+(link:https://godbolt.org/z/c4Pe4KvG9[Try Online])
+
 [source,glsl]
 ----
 layout(binding = 0) buffer block {
@@ -217,6 +225,8 @@ OpMemberDecorate %block 2 Offset 20
 
 === Alignment Example 4
 
+(link:https://godbolt.org/z/rG17jorf8[Try Online])
+
 [source,glsl]
 ----
 layout (binding = 0) buffer block {

lang/jp/chapters/hlsl.adoc

@@ -43,6 +43,7 @@ HLSL を Vulkan に対応させるため、Vulkan 固有の機能に対するイ
 ここでは、両言語で書かれた同じシェーダを、前述した名前空間による明示的な位置指定などを含めて、どのように異なるかを簡単に比較します。
 
 === GLSL
+link:https://godbolt.org/z/jcPofTK9j[オンラインで試す]
 [source,glsl]
 ----
 #version 450
@@ -67,6 +68,7 @@ void main()
 ----
 
 === HLSL
+https://godbolt.org/z/Y4sd9anMY[オンラインで試す]
 [source,hlsl]
 ----
 struct VSInput
@@ -94,7 +96,7 @@ VSOutput main(VSInput input, uint VertexIndex : SV_VertexID)
 {
 	VSOutput output = (VSOutput)0;
 	output.Color = input.Color * float(VertexIndex);
-	output.Position = mul(ubo.projectionMatrix, mul(ubo.viewMatrix, mul(ubo.modelMatrix, float4(input.Position.xyz, 1.0))));
+	output.Pos = mul(ubo.projectionMatrix, mul(ubo.viewMatrix, mul(ubo.modelMatrix, float4(input.Position.xyz, 1.0))));
 	return output;
 }
 ----