renderer_vulkan: Disable dynamic index conditionally (#20)

src/video_core/host_shaders/vulkan_present.frag

@@ -20,6 +20,21 @@ layout (push_constant, std140) uniform DrawInfo {
 
 layout (set = 0, binding = 0) uniform sampler2D screen_textures[3];
 
-void main() {
-    color = texture(screen_textures[screen_id_l], frag_tex_coord);
+vec4 GetScreen(int screen_id) {
+#ifdef ARRAY_DYNAMIC_INDEX
+    return texture(screen_textures[screen_id], frag_tex_coord);
+#else
+    switch (screen_id) {
+    case 0:
+        return texture(screen_textures[0], frag_tex_coord);
+    case 1:
+        return texture(screen_textures[1], frag_tex_coord);
+    case 2:
+        return texture(screen_textures[2], frag_tex_coord);
+    }
+#endif
+}
+
+void main() {
+    color = GetScreen(screen_id_l);
 }

src/video_core/host_shaders/vulkan_present_anaglyph.frag

@@ -32,8 +32,23 @@ layout (push_constant, std140) uniform DrawInfo {
 
 layout (set = 0, binding = 0) uniform sampler2D screen_textures[3];
 
+vec4 GetScreen(int screen_id) {
+#ifdef ARRAY_DYNAMIC_INDEX
+    return texture(screen_textures[screen_id], frag_tex_coord);
+#else
+    switch (screen_id) {
+    case 0:
+        return texture(screen_textures[0], frag_tex_coord);
+    case 1:
+        return texture(screen_textures[1], frag_tex_coord);
+    case 2:
+        return texture(screen_textures[2], frag_tex_coord);
+    }
+#endif
+}
+
 void main() {
-    vec4 color_tex_l = texture(screen_textures[screen_id_l], frag_tex_coord);
-    vec4 color_tex_r = texture(screen_textures[screen_id_r], frag_tex_coord);
+    vec4 color_tex_l = GetScreen(screen_id_l);
+    vec4 color_tex_r = GetScreen(screen_id_r);
     color = vec4(color_tex_l.rgb*l+color_tex_r.rgb*r, color_tex_l.a);
 }

src/video_core/host_shaders/vulkan_present_interlaced.frag

@@ -20,10 +20,25 @@ layout (push_constant, std140) uniform DrawInfo {
 
 layout (set = 0, binding = 0) uniform sampler2D screen_textures[3];
 
+vec4 GetScreen(int screen_id) {
+#ifdef ARRAY_DYNAMIC_INDEX
+    return texture(screen_textures[screen_id], frag_tex_coord);
+#else
+    switch (screen_id) {
+    case 0:
+        return texture(screen_textures[0], frag_tex_coord);
+    case 1:
+        return texture(screen_textures[1], frag_tex_coord);
+    case 2:
+        return texture(screen_textures[2], frag_tex_coord);
+    }
+#endif
+}
+
 void main() {
     float screen_row = o_resolution.x * frag_tex_coord.x;
     if (int(screen_row) % 2 == reverse_interlaced)
-        color = texture(screen_textures[screen_id_l], frag_tex_coord);
+        color = GetScreen(screen_id_l);
     else
-        color = texture(screen_textures[screen_id_r], frag_tex_coord);
+        color = GetScreen(screen_id_r);
 }

src/video_core/renderer_vulkan/renderer_vulkan.cpp

@@ -224,15 +224,17 @@ void RendererVulkan::LoadFBToScreenInfo(const Pica::FramebufferConfig& framebuff
 }
 
 void RendererVulkan::CompileShaders() {
-    vk::Device device = instance.GetDevice();
+    const vk::Device device = instance.GetDevice();
+    const std::string_view preamble =
+        instance.IsImageArrayDynamicIndexSupported() ? "#define ARRAY_DYNAMIC_INDEX" : "";
     present_vertex_shader =
         Compile(HostShaders::VULKAN_PRESENT_VERT, vk::ShaderStageFlagBits::eVertex, device);
-    present_shaders[0] =
-        Compile(HostShaders::VULKAN_PRESENT_FRAG, vk::ShaderStageFlagBits::eFragment, device);
+    present_shaders[0] = Compile(HostShaders::VULKAN_PRESENT_FRAG,
+                                 vk::ShaderStageFlagBits::eFragment, device, preamble);
     present_shaders[1] = Compile(HostShaders::VULKAN_PRESENT_ANAGLYPH_FRAG,
-                                 vk::ShaderStageFlagBits::eFragment, device);
+                                 vk::ShaderStageFlagBits::eFragment, device, preamble);
     present_shaders[2] = Compile(HostShaders::VULKAN_PRESENT_INTERLACED_FRAG,
-                                 vk::ShaderStageFlagBits::eFragment, device);
+                                 vk::ShaderStageFlagBits::eFragment, device, preamble);
 
     auto properties = instance.GetPhysicalDevice().getProperties();
     for (std::size_t i = 0; i < present_samplers.size(); i++) {

src/video_core/renderer_vulkan/vk_instance.h

@@ -248,6 +248,11 @@ public:
         return triangle_fan_supported;
     }
 
+    /// Returns true if dynamic indices can be used inside shaders.
+    bool IsImageArrayDynamicIndexSupported() const {
+        return features.shaderSampledImageArrayDynamicIndexing;
+    }
+
     /// Returns the minimum vertex stride alignment
     u32 GetMinVertexStrideAlignment() const {
         return min_vertex_stride_alignment;

src/video_core/renderer_vulkan/vk_shader_util.cpp

@@ -158,7 +158,8 @@ bool InitializeCompiler() {
 }
 } // Anonymous namespace
 
-vk::ShaderModule Compile(std::string_view code, vk::ShaderStageFlagBits stage, vk::Device device) {
+vk::ShaderModule Compile(std::string_view code, vk::ShaderStageFlagBits stage, vk::Device device,
+                         std::string_view premable) {
     if (!InitializeCompiler()) {
         return {};
     }
@@ -176,6 +177,7 @@ vk::ShaderModule Compile(std::string_view code, vk::ShaderStageFlagBits stage, v
     shader->setEnvTarget(glslang::EShTargetSpv,
                          glslang::EShTargetLanguageVersion::EShTargetSpv_1_3);
     shader->setStringsWithLengths(&pass_source_code, &pass_source_code_length, 1);
+    shader->setPreamble(premable.data());
 
     glslang::TShader::ForbidIncluder includer;
     if (!shader->parse(&DefaultTBuiltInResource, default_version, profile, false, true, messages,

src/video_core/renderer_vulkan/vk_shader_util.h

@@ -16,7 +16,8 @@ namespace Vulkan {
  * @param stage The pipeline stage the shader will be used in.
  * @param device The vulkan device handle.
  */
-vk::ShaderModule Compile(std::string_view code, vk::ShaderStageFlagBits stage, vk::Device device);
+vk::ShaderModule Compile(std::string_view code, vk::ShaderStageFlagBits stage, vk::Device device,
+                         std::string_view premable = "");
 
 /**
  * @brief Creates a vulkan shader module from SPIR-V bytecode.