render: Add support for private-platform shaders in GPU backend

src/render/gpu/SDL_shaders_gpu.c

@@ -33,6 +33,15 @@ typedef struct GPU_ShaderModuleSource
     SDL_GPUShaderFormat format;
 } GPU_ShaderModuleSource;
 
+#if defined(SDL_GPU_PRIVATE)
+#define IF_PRIVATE(...)     __VA_ARGS__
+#define HAVE_PRIVATE_SHADERS 1
+#include "SDL_render_private_shaders.h"
+#else
+#define IF_PRIVATE(...)
+#define HAVE_PRIVATE_SHADERS 0
+#endif
+
 #if defined(SDL_GPU_VULKAN) && SDL_GPU_VULKAN
 #define IF_VULKAN(...)     __VA_ARGS__
 #define HAVE_SPIRV_SHADERS 1
@@ -62,6 +71,7 @@ typedef struct GPU_ShaderModuleSource
 
 typedef struct GPU_ShaderSources
 {
+    IF_PRIVATE(GPU_ShaderModuleSource private;)
     IF_VULKAN(GPU_ShaderModuleSource spirv;)
     IF_D3D12(GPU_ShaderModuleSource dxil60;)
     IF_METAL(GPU_ShaderModuleSource msl;)
@@ -69,6 +79,9 @@ typedef struct GPU_ShaderSources
     unsigned int num_uniform_buffers;
 } GPU_ShaderSources;
 
+#define SHADER_PRIVATE(code) \
+    IF_PRIVATE(.private = { code, sizeof(code), SDL_GPU_SHADERFORMAT_PRIVATE }, )
+
 #define SHADER_SPIRV(code) \
     IF_VULKAN(.spirv = { code, sizeof(code), SDL_GPU_SHADERFORMAT_SPIRV }, )
 
@@ -83,6 +96,7 @@ static const GPU_ShaderSources vert_shader_sources[NUM_VERT_SHADERS] = {
     [VERT_SHADER_LINEPOINT] = {
         .num_samplers = 0,
         .num_uniform_buffers = 1,
+        SHADER_PRIVATE(linepoint_vert_private)
         SHADER_SPIRV(linepoint_vert_spv)
         SHADER_DXIL60(linepoint_vert_dxil)
         SHADER_METAL(linepoint_vert_msl)
@@ -90,6 +104,7 @@ static const GPU_ShaderSources vert_shader_sources[NUM_VERT_SHADERS] = {
     [VERT_SHADER_TRI_COLOR] = {
         .num_samplers = 0,
         .num_uniform_buffers = 1,
+        SHADER_PRIVATE(tri_color_vert_private)
         SHADER_SPIRV(tri_color_vert_spv)
         SHADER_DXIL60(tri_color_vert_dxil)
         SHADER_METAL(tri_color_vert_msl)
@@ -97,6 +112,7 @@ static const GPU_ShaderSources vert_shader_sources[NUM_VERT_SHADERS] = {
     [VERT_SHADER_TRI_TEXTURE] = {
         .num_samplers = 0,
         .num_uniform_buffers = 1,
+        SHADER_PRIVATE(tri_texture_vert_private)
         SHADER_SPIRV(tri_texture_vert_spv)
         SHADER_DXIL60(tri_texture_vert_dxil)
         SHADER_METAL(tri_texture_vert_msl)
@@ -107,6 +123,7 @@ static const GPU_ShaderSources frag_shader_sources[NUM_FRAG_SHADERS] = {
     [FRAG_SHADER_COLOR] = {
         .num_samplers = 0,
         .num_uniform_buffers = 1,
+        SHADER_PRIVATE(color_frag_private)
         SHADER_SPIRV(color_frag_spv)
         SHADER_DXIL60(color_frag_dxil)
         SHADER_METAL(color_frag_msl)
@@ -114,6 +131,7 @@ static const GPU_ShaderSources frag_shader_sources[NUM_FRAG_SHADERS] = {
     [FRAG_SHADER_TEXTURE_RGB] = {
         .num_samplers = 1,
         .num_uniform_buffers = 1,
+        SHADER_PRIVATE(texture_rgb_frag_private)
         SHADER_SPIRV(texture_rgb_frag_spv)
         SHADER_DXIL60(texture_rgb_frag_dxil)
         SHADER_METAL(texture_rgb_frag_msl)
@@ -121,6 +139,7 @@ static const GPU_ShaderSources frag_shader_sources[NUM_FRAG_SHADERS] = {
     [FRAG_SHADER_TEXTURE_RGBA] = {
         .num_samplers = 1,
         .num_uniform_buffers = 1,
+        SHADER_PRIVATE(texture_rgba_frag_private)
         SHADER_SPIRV(texture_rgba_frag_spv)
         SHADER_DXIL60(texture_rgba_frag_dxil)
         SHADER_METAL(texture_rgba_frag_msl)
@@ -128,6 +147,7 @@ static const GPU_ShaderSources frag_shader_sources[NUM_FRAG_SHADERS] = {
     [FRAG_SHADER_TEXTURE_ADVANCED] = {
         .num_samplers = 3,
         .num_uniform_buffers = 1,
+        SHADER_PRIVATE(texture_advanced_frag_private)
         SHADER_SPIRV(texture_advanced_frag_spv)
         SHADER_DXIL60(texture_advanced_frag_dxil)
         SHADER_METAL(texture_advanced_frag_msl)
@@ -143,6 +163,10 @@ static SDL_GPUShader *CompileShader(const GPU_ShaderSources *sources, SDL_GPUDev
     if (formats == SDL_GPU_SHADERFORMAT_INVALID) {
         // SDL_GetGPUShaderFormats already set the error
         return NULL;
+#if HAVE_PRIVATE_SHADERS
+    } else if (formats & SDL_GPU_SHADERFORMAT_PRIVATE) {
+        sms = &sources->private;
+#endif // HAVE_PRIVATE_SHADERS
 #if HAVE_SPIRV_SHADERS
     } else if (formats & SDL_GPU_SHADERFORMAT_SPIRV) {
         sms = &sources->spirv;
@@ -251,6 +275,7 @@ void GPU_FillSupportedShaderFormats(SDL_PropertiesID props)
         custom_shaders = true;
     }
     if (!custom_shaders) {
+        SDL_SetBooleanProperty(props, SDL_PROP_GPU_DEVICE_CREATE_SHADERS_PRIVATE_BOOLEAN, HAVE_PRIVATE_SHADERS);
         SDL_SetBooleanProperty(props, SDL_PROP_GPU_DEVICE_CREATE_SHADERS_SPIRV_BOOLEAN, HAVE_SPIRV_SHADERS);
         SDL_SetBooleanProperty(props, SDL_PROP_GPU_DEVICE_CREATE_SHADERS_DXIL_BOOLEAN, HAVE_DXIL60_SHADERS);
         SDL_SetBooleanProperty(props, SDL_PROP_GPU_DEVICE_CREATE_SHADERS_MSL_BOOLEAN, HAVE_METAL_SHADERS);