From 2e2d5d565300f09f025dfda711ff523a1e49a0f7 Mon Sep 17 00:00:00 2001
From: Ethan Lee <flibitijibibo@gmail.com>
Date: Mon, 7 Oct 2024 15:47:14 -0400
Subject: [PATCH] sdlgpu: Fill in blob compiler, still needs hash calculator

---
 mojoshader_sdlgpu.c | 120 ++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 117 insertions(+), 3 deletions(-)

diff --git a/mojoshader_sdlgpu.c b/mojoshader_sdlgpu.c
index 4189347..d976ca3 100644
--- a/mojoshader_sdlgpu.c
+++ b/mojoshader_sdlgpu.c
@@ -65,6 +65,7 @@ struct MOJOSHADER_sdlContext
 
     struct
     {
+        SDL_GPUShaderFormat format;
         uint32_t numShaders;
         ShaderEntry *hashes;
         ShaderBlob *shaders;
@@ -344,6 +345,7 @@ MOJOSHADER_sdlContext *MOJOSHADER_sdlCreateContext(
     {
         /* Just validate the bytecode, calculate a hash to find in blobCache */
         resultCtx->profile = "bytecode";
+        resultCtx->blob.format = SDL_GetGPUShaderFormats(device);
     }
     else
     {
@@ -462,6 +464,119 @@ MOJOSHADER_sdlShaderData *MOJOSHADER_sdlCompileShader(
     return NULL;
 } // MOJOSHADER_sdlCompileShader
 
+static inline uint64_t hash_vertex_shader(
+    MOJOSHADER_sdlContext *ctx,
+    MOJOSHADER_sdlShaderData *vshader,
+    MOJOSHADER_sdlVertexAttribute *vertexAttributes,
+    int vertexAttributeCount)
+{
+    // TODO: Combine d3dbc hash with vertex attribute hash
+}
+
+static inline uint64_t hash_pixel_shader(
+    MOJOSHADER_sdlContext *ctx,
+    MOJOSHADER_sdlShaderData *pshader)
+{
+    // TODO: Calculate hash of pshader d3dbc
+}
+
+static inline ShaderBlob *fetch_blob_shader(
+    MOJOSHADER_sdlContext *ctx,
+    uint64_t hash,
+    uint32_t *size)
+{
+    int32_t probes, searchIndex;
+    for (probes = 0; probes < ctx->blob.numShaders; probes += 1)
+    {
+        searchIndex = (hash + probes) % ctx->blob.numShaders;
+        if (ctx->blob.hashes[searchIndex].hash == hash)
+        {
+            *size = ctx->blob.hashes[searchIndex].size;
+            return &ctx->blob.shaders[searchIndex];
+        }
+    }
+    set_error("MojoShaderPrecompiled.bin is incomplete!!!");
+    return NULL;
+} // fetch_blob_shader
+
+static MOJOSHADER_sdlProgram *compile_blob_program(
+    MOJOSHADER_sdlContext *ctx,
+    MOJOSHADER_sdlShaderData *vshader,
+    MOJOSHADER_sdlShaderData *pshader,
+    MOJOSHADER_sdlVertexAttribute *vertexAttributes,
+    int vertexAttributeCount)
+{
+    uint64_t hash;
+    ShaderBlob *vblob, *pblob;
+    uint32_t vlen, plen;
+    SDL_GPUShaderCreateInfo createInfo;
+    MOJOSHADER_sdlProgram *program = (MOJOSHADER_sdlProgram*) ctx->malloc_fn(sizeof(MOJOSHADER_sdlProgram),
+                                                                             ctx->malloc_data);
+    if (program == NULL)
+    {
+        out_of_memory();
+        return NULL;
+    } // if
+
+    // TODO: Maybe add the format to the blob header?
+    SDL_assert(ctx->blob.format & SDL_GPU_SHADERFORMAT_PRIVATE);
+
+    hash = hash_vertex_shader(ctx, vshader, vertexAttributes, vertexAttributeCount);
+    vblob = fetch_blob_shader(ctx, hash, &vlen);
+
+    hash = hash_pixel_shader(ctx, pshader);
+    pblob = fetch_blob_shader(ctx, hash, &plen);
+
+    if ((vblob == NULL) || (pblob == NULL))
+    {
+        ctx->free_fn(program, ctx->malloc_data);
+        return NULL;
+    } // if
+
+    SDL_zero(createInfo);
+    createInfo.code = (const Uint8*) vblob->binary;
+    createInfo.code_size = vlen;
+    createInfo.entrypoint = vshader->parseData->mainfn;
+    createInfo.format = SDL_GPU_SHADERFORMAT_PRIVATE;
+    createInfo.stage = SDL_GPU_SHADERSTAGE_VERTEX;
+    createInfo.num_samplers = vshader->samplerSlots;
+    createInfo.num_uniform_buffers = 1;
+
+    program->vertexShader = SDL_CreateGPUShader(
+        ctx->device,
+        &createInfo
+    );
+
+    if (program->vertexShader == NULL)
+    {
+        set_error(SDL_GetError());
+        ctx->free_fn(program, ctx->malloc_data);
+        return NULL;
+    } // if
+
+    createInfo.code = (const Uint8*) pblob->binary;
+    createInfo.code_size = plen;
+    createInfo.entrypoint = pshader->parseData->mainfn;
+    createInfo.format = ctx->blob.format;
+    createInfo.stage = SDL_GPU_SHADERSTAGE_FRAGMENT;
+    createInfo.num_samplers = pshader->samplerSlots;
+
+    program->pixelShader = SDL_CreateGPUShader(
+        ctx->device,
+        &createInfo
+    );
+
+    if (program->pixelShader == NULL)
+    {
+        set_error(SDL_GetError());
+        SDL_ReleaseGPUShader(ctx->device, program->vertexShader);
+        ctx->free_fn(program, ctx->malloc_data);
+        return NULL;
+    } // if
+
+    return program;
+} // compile_blob_program
+
 static MOJOSHADER_sdlProgram *compile_spirv_program(
     MOJOSHADER_sdlContext *ctx,
     MOJOSHADER_sdlShaderData *vshader,
@@ -608,9 +723,8 @@ MOJOSHADER_sdlProgram *MOJOSHADER_sdlLinkProgram(
 
     if (ctx->blob.numShaders > 0)
     {
-        // TODO: Combine bytecode hash with vertex attribute hash, search the
-        // result in ctx->blob. If found, send to CompileShader directly,
-        // otherwise do a really loud error saying the blob cache is incomplete
+        program = compile_blob_program(ctx, vshader, pshader,
+                                       vertexAttributes, vertexAttributeCount);
     } // if
     else
     {