draw with indexes

3 files changed, 34 insertions, 14 deletions

diff --git a/examples/triangle/ex_triangle.c b/examples/triangle/ex_triangle.c
index c4f90f2..dc82156 100644
--- a/examples/triangle/ex_triangle.c
+++ b/examples/triangle/ex_triangle.c
@@ -19,9 +19,10 @@ extern core g_core;
 const custom_vertex vertices[] = {
   (custom_vertex){ .pos = vec2(-0.5, 0.5), .color = vec3(0.0, 0.0, 1.0) },
   (custom_vertex){ .pos = vec2(0.5, 0.5), .color = vec3(0.0, 1.0, 0.0) },
-  (custom_vertex){ .pos = vec2(0.0, -0.5), .color = vec3(1.0, 0.0, 0.0) },
+  (custom_vertex){ .pos = vec2(0.5, -0.5), .color = vec3(1.0, 0.0, 0.0) },
+  (custom_vertex){ .pos = vec2(-0.5, -0.5), .color = vec3(1.0, 1.0, 1.0) },
 };
-_Static_assert(sizeof(vertices) == (5 * 3 * sizeof(float)), "");
+const u16 indices[] = { 0, 1, 2, 2, 3, 0 };
 
 int main() {
   core_bringup();
@@ -56,12 +57,11 @@ int main() {
   };
   gpu_pipeline* gfx_pipeline = gpu_graphics_pipeline_create(pipeline_description);
 
-  buffer_handle triangle_vert_buf = gpu_buffer_create(
-      3 * sizeof(custom_vertex), CEL_BUFFER_VERTEX, CEL_BUFFER_FLAG_GPU,
-      vertices);  // gpu_buffer_create(3 * sizeof(custom_vertex), CEL_BUFFER_VERTEX);
-  /* buffer_upload_bytes(triangle_vert_buf, (bytebuffer){ .buf = vertices, .size = sizeof(vertices)
-   * }, */
-  /*                     0, sizeof(vertices)); */
+  buffer_handle triangle_vert_buf =
+      gpu_buffer_create(sizeof(vertices), CEL_BUFFER_VERTEX, CEL_BUFFER_FLAG_GPU, vertices);
+
+  buffer_handle triangle_index_buf =
+      gpu_buffer_create(sizeof(indices), CEL_BUFFER_INDEX, CEL_BUFFER_FLAG_GPU, indices);
 
   // Main loop
   while (!should_exit(&g_core)) {
@@ -85,7 +85,8 @@ int main() {
 
     // Record draw calls
     encode_set_vertex_buffer(enc, triangle_vert_buf);
-    gpu_temp_draw(3);
+    encode_set_index_buffer(enc, triangle_index_buf);
+    gpu_temp_draw(6);
 
     // End recording
     gpu_cmd_encoder_end_render(enc);
diff --git a/src/renderer/backends/backend_vulkan.c b/src/renderer/backends/backend_vulkan.c
index e30d3c1..dbae96e 100644
--- a/src/renderer/backends/backend_vulkan.c
+++ b/src/renderer/backends/backend_vulkan.c
@@ -706,6 +706,11 @@ void encode_set_vertex_buffer(gpu_cmd_encoder* encoder, buffer_handle buf) {
   vkCmdBindVertexBuffers(encoder->cmd_buffer, 0, 1, vbs, offsets);
 }
 
+void encode_set_index_buffer(gpu_cmd_encoder* encoder, buffer_handle buf) {
+  gpu_buffer buffer = context.buffers[buf.raw];
+  vkCmdBindIndexBuffer(encoder->cmd_buffer, buffer.handle, 0, VK_INDEX_TYPE_UINT16);
+}
+
 // TEMP
 void encode_set_default_settings(gpu_cmd_encoder* encoder) {
   VkViewport viewport = { 0 };
@@ -751,9 +756,10 @@ bool gpu_backend_begin_frame() {
   return true;
 }
 
-void gpu_temp_draw(size_t n_verts) {
+void gpu_temp_draw(size_t n_indices) {
   gpu_cmd_encoder* encoder = gpu_get_default_cmd_encoder();  // &context.main_cmd_buf;
-  vkCmdDraw(encoder->cmd_buffer, n_verts, 1, 0, 0);
+  /* vkCmdDraw(encoder->cmd_buffer, n_verts, 1, 0, 0); */
+  vkCmdDrawIndexed(encoder->cmd_buffer, n_indices, 1, 0, 0, 0);
 }
 
 void gpu_backend_end_frame() {
@@ -1032,6 +1038,9 @@ buffer_handle gpu_buffer_create(u64 size, gpu_buffer_type buf_type, gpu_buffer_f
     case CEL_BUFFER_VERTEX:
       buffer_info.usage |= VK_BUFFER_USAGE_VERTEX_BUFFER_BIT;
       break;
+    case CEL_BUFFER_INDEX:
+      buffer_info.usage |= VK_BUFFER_USAGE_INDEX_BUFFER_BIT;
+      break;
     case CEL_BUFFER_COUNT:
       WARN("Incorrect gpu_buffer_type provided. using default");
       break;
@@ -1075,15 +1084,22 @@ buffer_handle gpu_buffer_create(u64 size, gpu_buffer_type buf_type, gpu_buffer_f
   context.buffer_count++;
 
   if (data) {
+    TRACE("Upload data as part of buffer creation");
     if (flags & CEL_BUFFER_FLAG_CPU) {
+      // map memory -> copy data in -> unmap memory
       buffer_upload_bytes(handle, (bytebuffer){ .buf = (u8*)data, .size = size }, 0, size);
     } else if (flags & CEL_BUFFER_FLAG_GPU) {
       TRACE("Uploading data to buffer using staging buffer");
-      buffer_handle staging =
-          gpu_buffer_create(size, CEL_BUFFER_DEFAULT, CEL_BUFFER_FLAG_CPU, data);
+      // Create a staging buffer
+      buffer_handle staging = gpu_buffer_create(size, buf_type, CEL_BUFFER_FLAG_CPU, NULL);
+
+      // Copy data into it
+      buffer_upload_bytes(staging, (bytebuffer){ .buf = (u8*)data, .size = size }, 0, size);
+
+      // Enqueue a copy from the staging buffer into the DEVICE_LOCAL buffer
       gpu_cmd_encoder temp_encoder = gpu_cmd_encoder_create();
       gpu_cmd_encoder_begin(temp_encoder);
-      encode_buffer_copy(&temp_encoder, handle, 0, staging, 0, size);
+      encode_buffer_copy(&temp_encoder, staging, 0, handle, 0, size);
       gpu_cmd_buffer copy_cmd_buffer = gpu_cmd_encoder_finish(&temp_encoder);
 
       VkSubmitInfo submit_info = { VK_STRUCTURE_TYPE_SUBMIT_INFO };
@@ -1091,6 +1107,7 @@ buffer_handle gpu_buffer_create(u64 size, gpu_buffer_type buf_type, gpu_buffer_f
       submit_info.pCommandBuffers = &temp_encoder.cmd_buffer;
       vkQueueSubmit(context.device->graphics_queue, 1, &submit_info, VK_NULL_HANDLE);
 
+      // Cleanup
       vkQueueWaitIdle(context.device->graphics_queue);
       gpu_cmd_encoder_destroy(&temp_encoder);
       gpu_buffer_destroy(staging);
@@ -1111,6 +1128,7 @@ void buffer_upload_bytes(buffer_handle gpu_buf, bytebuffer cpu_buf, u64 offset,
   gpu_buffer buffer = context.buffers[gpu_buf.raw];
   void* data_ptr;
   vkMapMemory(context.device->logical_device, buffer.memory, 0, size, 0, &data_ptr);
+  DEBUG("Uploading %d bytes to buffer", size);
   memcpy(data_ptr, cpu_buf.buf, size);
   vkUnmapMemory(context.device->logical_device, buffer.memory);
 }
diff --git a/src/renderer/ral_types.h b/src/renderer/ral_types.h
index 7dd254e..2fa8258 100644
--- a/src/renderer/ral_types.h
+++ b/src/renderer/ral_types.h
@@ -58,6 +58,7 @@ typedef struct texture_desc {
 typedef enum gpu_buffer_type {
   CEL_BUFFER_DEFAULT,  // on Vulkan this would be a storage buffer?
   CEL_BUFFER_VERTEX,
+  CEL_BUFFER_INDEX,
   CEL_BUFFER_COUNT
 } gpu_buffer_type;