From 8bd595989d03b7d18808a7e31ec3220024f31908 Mon Sep 17 00:00:00 2001
From: Camden Dixie O'Brien <cobrien@witekio.com>
Date: Wed, 1 Oct 2025 16:29:27 +0100
Subject: [PATCH] Load bone matrices for each frame

---
 gpu.c  | 12 +++++++++---
 gpu.h  |  4 +++-
 main.c |  2 +-
 3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/gpu.c b/gpu.c
index f320997..f775985 100644
--- a/gpu.c
+++ b/gpu.c
@@ -145,6 +145,9 @@ static void load_buffer(
 
 void gpu_init(gpu_ctx_t *ctx, const gpu_config_t *config, model_t model)
 {
+	ctx->index_count = model.index_count;
+	ctx->bone_count = model.bone_count;
+
 	// Initialise Vulkan instance.
 	const VkApplicationInfo app_info = {
 		.sType = VK_STRUCTURE_TYPE_APPLICATION_INFO,
@@ -776,7 +779,6 @@ void gpu_init(gpu_ctx_t *ctx, const gpu_config_t *config, model_t model)
 	// Set up staging, vertex and index buffers
 	const size_t vertex_data_size = model.vertex_count * sizeof(vertex_t);
 	const size_t index_data_size = model.index_count * sizeof(vertex_t);
-	ctx->index_count = model.index_count;
 	VkBuffer staging_buf;
 	VkDeviceMemory staging_buf_mem;
 	const size_t staging_buf_size = MAX(vertex_data_size, index_data_size);
@@ -869,7 +871,8 @@ void gpu_cleanup(const gpu_ctx_t *ctx)
 	vkDestroyInstance(ctx->inst, nullptr);
 }
 
-void gpu_render(const gpu_ctx_t *ctx, const mvp_t *mvp)
+void gpu_render(
+    const gpu_ctx_t *ctx, const mvp_t *mvp, const mat4_t *bone_matrices)
 {
 	VkResult result;
 
@@ -884,8 +887,11 @@ void gpu_render(const gpu_ctx_t *ctx, const mvp_t *mvp)
 	    &img_index);
 	assert(result == VK_SUCCESS);
 
-	// Copy MVP matricies into uniform buffer for this image
+	// Copy MVP and bone matricies into uniform buffer for this image
 	memcpy(ctx->mvps + img_index, mvp, sizeof(mvp_t));
+	memcpy(
+	    ctx->bone_matrices + (ctx->bone_count * img_index), bone_matrices,
+	    ctx->bone_count * sizeof(mat4_t));
 
 	// Reset command buffer, then begin writing
 	vkResetCommandBuffer(ctx->cmd_buf, 0);
diff --git a/gpu.h b/gpu.h
index c242544..497824f 100644
--- a/gpu.h
+++ b/gpu.h
@@ -53,6 +53,7 @@ typedef struct {
 	VkBuffer index_buf;
 	VkDeviceMemory index_buf_mem;
 	size_t index_count;
+	size_t bone_count;
 } gpu_ctx_t;
 
 typedef struct {
@@ -62,6 +63,7 @@ typedef struct {
 
 void gpu_init(gpu_ctx_t *ctx, const gpu_config_t *config, model_t model);
 void gpu_cleanup(const gpu_ctx_t *ctx);
-void gpu_render(const gpu_ctx_t *ctx, const mvp_t *mvp);
+void gpu_render(
+    const gpu_ctx_t *ctx, const mvp_t *mvp, const mat4_t *bone_matrices);
 
 #endif
diff --git a/main.c b/main.c
index cc8e9c0..af5c434 100644
--- a/main.c
+++ b/main.c
@@ -108,7 +108,7 @@ int main(int argc, char *argv[])
 			break;
 		}
 
-		gpu_render(&gpu, &mvp);
+		gpu_render(&gpu, &mvp, anim.bone_matrices);
 	}
 
 	// Clean up