Ensure correct blending function for transparent window

1 files changed, 26 insertions, 2 deletions

diff --git a/src/window/window.c b/src/window/window.c
index 586719d..ccbf8ef 100644
--- a/src/window/window.c
+++ b/src/window/window.c
@@ -85,6 +85,7 @@ typedef struct {
     GLXFBConfig *fbconfigs;
     GLXFBConfig fbconfig;
     XVisualInfo *visual_info;
+    bool support_alpha;
 
     /* This only contains connected and active monitors */
     mgl_monitor monitors[MAX_MONITORS];
@@ -185,6 +186,7 @@ static int x11_context_init(x11_context *self, bool alpha) {
     self->fbconfigs = NULL;
     self->fbconfig = NULL;
     self->visual_info = NULL;
+    self->support_alpha = alpha;
 
     memset(self->monitors, 0, sizeof(self->monitors));
     self->num_monitors = 0;
@@ -574,6 +576,7 @@ static int mgl_window_init(mgl_window *self, const char *title, const mgl_window
     self->num_monitors = 0;
 
     mgl_context *context = mgl_get_context();
+    context->current_window = self;
 
     Window parent_window = params ? params->parent_window : None;
     if(parent_window == 0)
@@ -700,7 +703,7 @@ static int mgl_window_init(mgl_window *self, const char *title, const mgl_window
     context->gl.glEnable(GL_TEXTURE_2D);
     context->gl.glEnable(GL_BLEND);
     context->gl.glEnable(GL_SCISSOR_TEST);
-    context->gl.glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+    mgl_window_set_render_blend_func(self);
     context->gl.glEnableClientState(GL_VERTEX_ARRAY);
     context->gl.glEnableClientState(GL_TEXTURE_COORD_ARRAY);
     context->gl.glEnableClientState(GL_COLOR_ARRAY);
@@ -765,6 +768,10 @@ void mgl_window_deinit(mgl_window *self) {
     self->clipboard_size = 0;
 
     self->open = false;
+
+    mgl_context *context = mgl_get_context();
+    if(context->current_window == self)
+        context->current_window = NULL;
 }
 
 /* Returns MGL_KEY_UNKNOWN on no match */
@@ -1256,7 +1263,13 @@ static void mgl_window_on_receive_event(mgl_window *self, XEvent *xev, mgl_event
 
 void mgl_window_clear(mgl_window *self, mgl_color color) {
     mgl_context *context = mgl_get_context();
-    context->gl.glClearColor((float)color.r / 255.0f, (float)color.g / 255.0f, (float)color.b / 255.0f, (float)color.a / 255.0f);
+    x11_context *x11_context = self->context;
+
+    const float alpha = (float)color.a / 255.0f;
+    if(x11_context->support_alpha)
+        context->gl.glClearColor(((float)color.r / 255.0f) * alpha, ((float)color.g / 255.0f) * alpha, ((float)color.b / 255.0f) * alpha, alpha);
+    else
+        context->gl.glClearColor((float)color.r / 255.0f, (float)color.g / 255.0f, (float)color.b / 255.0f, alpha);
     context->gl.glClear(GL_COLOR_BUFFER_BIT);
 }
 
@@ -1783,6 +1796,17 @@ void mgl_window_set_key_repeat_enabled(mgl_window *self, bool enabled) {
     self->key_repeat_enabled = enabled;
 }
 
+void mgl_window_set_texture_blend_func(mgl_window *self) {
+    mgl_context *context = mgl_get_context();
+    context->gl.glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+}
+
+void mgl_window_set_render_blend_func(mgl_window *self) {
+    mgl_context *context = mgl_get_context();
+    x11_context *x11_context = self->context;
+    context->gl.glBlendFunc(x11_context->support_alpha ? GL_ONE : GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+}
+
 void mgl_window_flush(mgl_window *self) {
     mgl_context *context = mgl_get_context();
     XFlush(context->connection);