From cc526e1d895bb4b104d95bd0c574640b2661a5c9 Mon Sep 17 00:00:00 2001
From: Joshua Goins <josh@redstrate.com>
Date: Mon, 3 Oct 2022 22:49:19 -0400
Subject: [PATCH] Add dummy Vulkan backend

---
 Makefile                  |   3 +-
 src/pc/gfx/gfx_vulkan.cpp | 110 ++++++++++++++++++++++++++++++++++++++
 src/pc/gfx/gfx_vulkan.h   |  12 +++++
 src/pc/pc_main.c          |   1 +
 4 files changed, 125 insertions(+), 1 deletion(-)
 create mode 100644 src/pc/gfx/gfx_vulkan.cpp
 create mode 100644 src/pc/gfx/gfx_vulkan.h

diff --git a/Makefile b/Makefile
index d620f92..8e80b58 100644
--- a/Makefile
+++ b/Makefile
@@ -490,7 +490,8 @@ PLATFORM_CFLAGS += -DNO_SEGMENTED_MEMORY -DUSE_SYSTEM_MALLOC
 
 # Compiler and linker flags for graphics backend
 ifeq ($(ENABLE_OPENGL),1)
-  GFX_CFLAGS  := -DENABLE_OPENGL
+  # TODO: right now the opengl and vulkan backends are linked, will seperate later...
+  GFX_CFLAGS  := -DENABLE_OPENGL -DENABLE_VULKAN
   GFX_LDFLAGS :=
   ifeq ($(TARGET_WINDOWS),1)
     GFX_CFLAGS  += $(shell sdl2-config --cflags) -DGLEW_STATIC
diff --git a/src/pc/gfx/gfx_vulkan.cpp b/src/pc/gfx/gfx_vulkan.cpp
new file mode 100644
index 0000000..b44b8f8
--- /dev/null
+++ b/src/pc/gfx/gfx_vulkan.cpp
@@ -0,0 +1,110 @@
+#ifdef ENABLE_VULKAN
+
+#include <time.h>
+#include <errno.h>
+
+#include "gfx_rendering_api.h"
+
+static bool gfx_vulkan_renderer_z_is_from_0_to_1(void) {
+    return false;
+}
+
+static void gfx_vulkan_renderer_unload_shader(struct ShaderProgram *old_prg) {
+}
+
+static void gfx_vulkan_renderer_load_shader(struct ShaderProgram *new_prg) {
+}
+
+static struct ShaderProgram *gfx_vulkan_renderer_create_and_load_new_shader(uint32_t shader_id) {
+    return NULL;
+}
+
+static struct ShaderProgram *gfx_vulkan_renderer_lookup_shader(uint32_t shader_id) {
+    return NULL;
+}
+
+static void gfx_vulkan_renderer_shader_get_info(struct ShaderProgram *prg, uint8_t *num_inputs, bool used_textures[2]) {
+    *num_inputs = 0;
+    used_textures[0] = false;
+    used_textures[1] = false;
+}
+
+static uint32_t gfx_vulkan_renderer_new_texture(void) {
+    return 0;
+}
+
+static void gfx_vulkan_renderer_select_texture(int tile, uint32_t texture_id) {
+}
+
+static void gfx_vulkan_renderer_upload_texture(const uint8_t *rgba32_buf, int width, int height) {
+}
+
+static void gfx_vulkan_renderer_set_sampler_parameters(int tile, bool linear_filter, uint32_t cms, uint32_t cmt) {
+}
+
+static void gfx_vulkan_renderer_set_depth_test(bool depth_test) {
+}
+
+static void gfx_vulkan_renderer_set_depth_mask(bool z_upd) {
+}
+
+static void gfx_vulkan_renderer_set_zmode_decal(bool zmode_decal) {
+}
+
+static void gfx_vulkan_renderer_set_viewport(int x, int y, int width, int height) {
+}
+
+static void gfx_vulkan_renderer_set_scissor(int x, int y, int width, int height) {
+}
+
+static void gfx_vulkan_renderer_set_use_alpha(bool use_alpha) {
+}
+
+static void gfx_vulkan_renderer_draw_triangles(float buf_vbo[], size_t buf_vbo_len, size_t buf_vbo_num_tris) {
+}
+
+static void gfx_vulkan_renderer_init(void) {
+}
+
+static void gfx_vulkan_renderer_on_resize(void) {
+}
+
+static void gfx_vulkan_renderer_start_frame(void) {
+}
+
+static void gfx_vulkan_renderer_end_frame(void) {
+}
+
+static void gfx_vulkan_renderer_finish_render(void) {
+}
+
+static const char* gfx_vulkan_get_name() {
+    return "Vulkan";
+}
+
+struct GfxRenderingAPI gfx_vulkan_api = {
+    gfx_vulkan_renderer_z_is_from_0_to_1,
+    gfx_vulkan_renderer_unload_shader,
+    gfx_vulkan_renderer_load_shader,
+    gfx_vulkan_renderer_create_and_load_new_shader,
+    gfx_vulkan_renderer_lookup_shader,
+    gfx_vulkan_renderer_shader_get_info,
+    gfx_vulkan_renderer_new_texture,
+    gfx_vulkan_renderer_select_texture,
+    gfx_vulkan_renderer_upload_texture,
+    gfx_vulkan_renderer_set_sampler_parameters,
+    gfx_vulkan_renderer_set_depth_test,
+    gfx_vulkan_renderer_set_depth_mask,
+    gfx_vulkan_renderer_set_zmode_decal,
+    gfx_vulkan_renderer_set_viewport,
+    gfx_vulkan_renderer_set_scissor,
+    gfx_vulkan_renderer_set_use_alpha,
+    gfx_vulkan_renderer_draw_triangles,
+    gfx_vulkan_renderer_init,
+    gfx_vulkan_renderer_on_resize,
+    gfx_vulkan_renderer_start_frame,
+    gfx_vulkan_renderer_end_frame,
+    gfx_vulkan_renderer_finish_render,
+    gfx_vulkan_get_name,
+};
+#endif
diff --git a/src/pc/gfx/gfx_vulkan.h b/src/pc/gfx/gfx_vulkan.h
new file mode 100644
index 0000000..282f0d9
--- /dev/null
+++ b/src/pc/gfx/gfx_vulkan.h
@@ -0,0 +1,12 @@
+#ifdef ENABLE_VULKAN
+
+#ifndef GFX_VULKAN_H
+#define GFX_VULKAN_H
+
+#include "gfx_rendering_api.h"
+
+extern struct GfxRenderingAPI gfx_vulkan_api;
+
+#endif
+
+#endif
diff --git a/src/pc/pc_main.c b/src/pc/pc_main.c
index 6fe3f6b..44a2310 100644
--- a/src/pc/pc_main.c
+++ b/src/pc/pc_main.c
@@ -18,6 +18,7 @@
 #include "gfx/gfx_glx.h"
 #include "gfx/gfx_sdl.h"
 #include "gfx/gfx_dummy.h"
+#include "gfx/gfx_vulkan.h"
 
 #include "audio/audio_api.h"
 #include "audio/audio_wasapi.h"