library: set gl blend function when drawing

src/library/dll/main.c

@@ -52,6 +52,7 @@ static void hook_glDeleteTextures(GLsizei, const GLuint*);
 static void hook_glClear(GLbitfield);
 static void hook_glViewport(GLint, GLint, GLsizei, GLsizei);
 static void hook_glTexParameteri(GLenum, GLenum, GLint);
+static void hook_glBlendFunc(GLenum, GLenum);
 
 static HGLRC __stdcall hook_wglCreateContextAttribsARB(HDC, HGLRC, const int*);
 
@@ -99,6 +100,7 @@ DWORD __stdcall BOLT_STUB_ENTRYNAME(struct PluginInjectParams* data) {
     // get the functions we need from libgl
     HMODULE libgl_module = data->pGetModuleHandleW(L"opengl32.dll");
     libgl.BindTexture = (void(*)(GLenum, GLuint))data->pGetProcAddress(libgl_module, "glBindTexture");
+    libgl.BlendFunc = (void(*)(GLenum, GLenum))data->pGetProcAddress(libgl_module, "glBlendFunc");
     libgl.Clear = (void(*)(GLbitfield))data->pGetProcAddress(libgl_module, "glClear");
     libgl.ClearColor = (void(*)(GLfloat, GLfloat, GLfloat, GLfloat))data->pGetProcAddress(libgl_module, "glClearColor");
     libgl.DeleteTextures = (void(*)(GLsizei, const GLuint*))data->pGetProcAddress(libgl_module, "glDeleteTextures");
@@ -145,6 +147,7 @@ DWORD __stdcall BOLT_STUB_ENTRYNAME(struct PluginInjectParams* data) {
                     FNHOOK(glTexParameteri)
                     FNHOOK(glClear)
                     FNHOOK(glViewport)
+                    FNHOOK(glBlendFunc)
                 }
                 if (bolt_cmp(module_name, "gdi32.dll", 0)) {
                     FNHOOKA(SwapBuffers, SWAPBUFFERS)
@@ -417,6 +420,13 @@ static void hook_glViewport(GLint x, GLint y, GLsizei width, GLsizei height) {
     LOG("glViewport end\n");
 }
 
+static hook_glBlendFunc(GLenum sfactor, GLenum dfactor) {
+    LOG("glBlendFunc\n");
+    libgl.BlendFunc(sfactor, dfactor);
+    _bolt_gl_onBlendFunc(sfactor, dfactor);
+    LOG("glBlendFunc end\n");
+}
+
 static HGLRC __stdcall hook_wglCreateContextAttribsARB(HDC hdc, HGLRC hglrc, const int* attribList) {
     LOGF("wglCreateContextAttribsARB(%llu)\n", (ULONGLONG)hglrc);
     EnterCriticalSection(&wgl_lock);

src/library/gl.c

@@ -146,6 +146,10 @@ struct GLContext {
     GLint viewport_y;
     GLsizei viewport_w;
     GLsizei viewport_h;
+    GLenum blend_rgb_s;
+    GLenum blend_rgb_d;
+    GLenum blend_alpha_s;
+    GLenum blend_alpha_d;
 };
 
 static unsigned int gl_width;
@@ -648,6 +652,10 @@ static void _bolt_glcontext_init(struct GLContext* context, void* egl_context, v
     context->does_blit_3d_target = false;
     context->recalculate_sSceneHDRTex = false;
     context->depth_of_field_enabled = false;
+    context->blend_rgb_s = GL_ONE;
+    context->blend_rgb_d = GL_ZERO;
+    context->blend_alpha_s = GL_ONE;
+    context->blend_alpha_d = GL_ZERO;
     if (shared) {
         context->programs = shared->programs;
         context->buffers = shared->buffers;
@@ -827,6 +835,7 @@ static void _bolt_gl_load(void* (*GetProcAddress)(const char*)) {
     INIT_GL_FUNC(BindBuffer)
     INIT_GL_FUNC(BindFramebuffer)
     INIT_GL_FUNC(BindVertexArray)
+    INIT_GL_FUNC(BlendFuncSeparate)
     INIT_GL_FUNC(BlitFramebuffer)
     INIT_GL_FUNC(BufferData)
     INIT_GL_FUNC(BufferStorage)
@@ -1594,6 +1603,15 @@ static void _bolt_glBlitFramebuffer(GLint srcX0, GLint srcY0, GLint srcX1, GLint
     LOG("glBlitFramebuffer end\n");
 }
 
+static void _bolt_glBlendFuncSeparate(GLenum srcRGB, GLenum dstRGB, GLenum srcAlpha, GLenum dstAlpha) {
+    gl.BlendFuncSeparate(srcRGB, dstRGB, srcAlpha, dstAlpha);
+    struct GLContext* c = _bolt_context();
+    c->blend_rgb_s = srcRGB;
+    c->blend_rgb_d = dstRGB;
+    c->blend_alpha_s = srcAlpha;
+    c->blend_alpha_d = dstAlpha;
+}
+
 void* _bolt_gl_GetProcAddress(const char* name) {
 #define PROC_ADDRESS_MAP(FUNC) if (!strcmp(name, "gl"#FUNC)) { return gl.FUNC ? _bolt_gl##FUNC : NULL; }
     PROC_ADDRESS_MAP(CreateProgram)
@@ -1622,6 +1640,7 @@ void* _bolt_gl_GetProcAddress(const char* name) {
     PROC_ADDRESS_MAP(DeleteVertexArrays)
     PROC_ADDRESS_MAP(BindVertexArray)
     PROC_ADDRESS_MAP(BlitFramebuffer)
+    PROC_ADDRESS_MAP(BlendFuncSeparate)
 #undef PROC_ADDRESS_MAP
     return NULL;
 }
@@ -2222,6 +2241,14 @@ void _bolt_gl_onTexParameteri(GLenum target, GLenum pname, GLint param) {
     }
 }
 
+void _bolt_gl_onBlendFunc(GLenum sfactor, GLenum dfactor) {
+    struct GLContext* c = _bolt_context();
+    c->blend_rgb_s = sfactor;
+    c->blend_rgb_d = dfactor;
+    c->blend_alpha_s = sfactor;
+    c->blend_alpha_d = dfactor;
+}
+
 static void _bolt_gl_plugin_drawelements_vertex2d_xy(size_t index, void* userdata, int32_t* out) {
     struct GLPluginDrawElementsVertex2DUserData* data = userdata;
     if (_bolt_get_attr_binding_int(data->c, data->position, data->indices[index], 2, out)) {
@@ -2531,8 +2558,10 @@ static void _bolt_gl_plugin_surface_drawtoscreen(void* _userdata, int sx, int sy
     lgl->Disable(GL_DEPTH_TEST);
     lgl->Disable(GL_SCISSOR_TEST);
     lgl->Disable(GL_CULL_FACE);
+    lgl->BlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
     lgl->DrawArrays(GL_TRIANGLE_STRIP, 0, 4);
 
+    gl.BlendFuncSeparate(c->blend_rgb_s, c->blend_rgb_d, c->blend_alpha_s, c->blend_alpha_d);
     if (depth_test) lgl->Enable(GL_DEPTH_TEST);
     if (scissor_test) lgl->Enable(GL_SCISSOR_TEST);
     if (cull_face) lgl->Enable(GL_CULL_FACE);
@@ -2566,8 +2595,10 @@ static void _bolt_gl_plugin_surface_drawtosurface(void* _userdata, void* _target
     lgl->Disable(GL_DEPTH_TEST);
     lgl->Disable(GL_SCISSOR_TEST);
     lgl->Disable(GL_CULL_FACE);
+    lgl->BlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
     lgl->DrawArrays(GL_TRIANGLE_STRIP, 0, 4);
 
+    gl.BlendFuncSeparate(c->blend_rgb_s, c->blend_rgb_d, c->blend_alpha_s, c->blend_alpha_d);
     if (depth_test) lgl->Enable(GL_DEPTH_TEST);
     if (scissor_test) lgl->Enable(GL_SCISSOR_TEST);
     if (cull_face) lgl->Enable(GL_CULL_FACE);

src/library/gl.h

@@ -33,6 +33,10 @@ typedef uintptr_t GLsizeiptr;
 
 /* consts used from libgl */
 #define GL_NONE 0
+#define GL_ZERO 0
+#define GL_ONE 1
+#define GL_SRC_ALPHA 770
+#define GL_ONE_MINUS_SRC_ALPHA 771
 #define GL_TEXTURE 5890
 #define GL_TEXTURE_2D 3553
 #define GL_TEXTURE_2D_MULTISAMPLE 37120
@@ -130,6 +134,7 @@ struct GLProcFunctions {
     void (*BindBuffer)(GLenum, GLuint);
     void (*BindFramebuffer)(GLenum, GLuint);
     void (*BindVertexArray)(GLuint);
+    void (*BlendFuncSeparate)(GLenum, GLenum, GLenum, GLenum);
     void (*BlitFramebuffer)(GLint, GLint, GLint, GLint, GLint, GLint, GLint, GLint, GLbitfield, GLenum);
     void (*BufferData)(GLenum, GLsizeiptr, const void*, GLenum);
     void (*BufferStorage)(GLenum, GLsizeiptr, const void*, GLbitfield);
@@ -200,6 +205,7 @@ struct GLProcFunctions {
 /// Struct representing all the OpenGL functions of interest to us that the game gets from static or dynamic linkage
 struct GLLibFunctions {
     void (*BindTexture)(GLenum, GLuint);
+    void (*BlendFunc)(GLenum, GLenum);
     void (*Clear)(GLbitfield);
     void (*ClearColor)(GLfloat, GLfloat, GLfloat, GLfloat);
     void (*DeleteTextures)(GLsizei, const GLuint*);
@@ -274,4 +280,7 @@ void _bolt_gl_onViewport(GLint, GLint, GLsizei, GLsizei);
 /// Call this in response to glTexParameteri, which needs to be hooked from libgl.
 void _bolt_gl_onTexParameteri(GLenum, GLenum, GLint);
 
+/// Call this in response to glBlendFunc, which needs to be hooked from libgl.
+void _bolt_gl_onBlendFunc(GLenum, GLenum);
+
 #endif

src/library/so/main.c

@@ -201,6 +201,8 @@ static void _bolt_init_libgl(unsigned long addr, const Elf32_Word* gnu_hash_tabl
     libgl_addr = (void*)addr;
     const ElfW(Sym)* sym = _bolt_lookup_symbol("glBindTexture", gnu_hash_table, hash_table, string_table, symbol_table);
     if (sym) libgl.BindTexture = sym->st_value + libgl_addr;
+    sym = _bolt_lookup_symbol("glBlendFunc", gnu_hash_table, hash_table, string_table, symbol_table);
+    if (sym) libgl.BlendFunc = sym->st_value + libgl_addr;
     sym = _bolt_lookup_symbol("glClear", gnu_hash_table, hash_table, string_table, symbol_table);
     if (sym) libgl.Clear = sym->st_value + libgl_addr;
     sym = _bolt_lookup_symbol("glClearColor", gnu_hash_table, hash_table, string_table, symbol_table);
@@ -386,6 +388,13 @@ void glTexParameteri(GLenum target, GLenum pname, GLint param) {
     LOG("glTexParameteri end\n");
 }
 
+void glBlendFunc(GLenum sfactor, GLenum dfactor) {
+    LOG("glBlendFunc\n");
+    libgl.BlendFunc(sfactor, dfactor);
+    _bolt_gl_onBlendFunc(sfactor, dfactor);
+    LOG("glBlendFunc end\n");
+}
+
 void* eglGetProcAddress(const char* name) {
     LOGF("eglGetProcAddress('%s')\n", name);
     void* ret = _bolt_gl_GetProcAddress(name);
@@ -766,6 +775,7 @@ static void* _bolt_dl_lookup(void* handle, const char* symbol) {
         if (strcmp(symbol, "glClear") == 0) return glClear;
         if (strcmp(symbol, "glViewport") == 0) return glViewport;
         if (strcmp(symbol, "glTexParameteri") == 0) return glTexParameteri;
+        if (strcmp(symbol, "glBlendFunc") == 0) return glBlendFunc;
     } else if (handle == libxcb_addr) {
         if (strcmp(symbol, "xcb_poll_for_event") == 0) return xcb_poll_for_event;
         if (strcmp(symbol, "xcb_poll_for_queued_event") == 0) return xcb_poll_for_queued_event;