add display state

src/dusksdl2/display/displaysdl2.c

@@ -102,6 +102,42 @@ errorret_t displaySDL2Swap(void) {
   errorOk();
 }
 
+errorret_t displaySDL2SetState(displaystate_t state) {
+  if(state.flags & DISPLAY_STATE_FLAG_CULL) {
+    glEnable(GL_CULL_FACE);
+    errorChain(errorGLCheck());
+    glCullFace(GL_BACK);
+    errorChain(errorGLCheck());
+  } else {
+    glDisable(GL_CULL_FACE);
+    errorChain(errorGLCheck());
+  }
+
+  if(state.flags & DISPLAY_STATE_FLAG_DEPTH_TEST) {
+    glEnable(GL_DEPTH_TEST);
+    errorChain(errorGLCheck());
+    glDepthFunc(GL_LEQUAL);
+    errorChain(errorGLCheck());
+    glClearDepth(1.0f);
+    errorChain(errorGLCheck());
+  } else {
+    glDisable(GL_DEPTH_TEST);
+    errorChain(errorGLCheck());
+  }
+
+  if(state.flags & DISPLAY_STATE_FLAG_BLEND) {
+    glEnable(GL_BLEND);
+    errorChain(errorGLCheck());
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+    errorChain(errorGLCheck());
+  } else {
+    glDisable(GL_BLEND);
+    errorChain(errorGLCheck());
+  }
+
+  errorOk();
+}
+
 void displaySDL2Dispose(void) {
   if(DISPLAY.glContext) {
     SDL_GL_DeleteContext(DISPLAY.glContext);

src/dusksdl2/display/displaysdl2.h

@@ -7,6 +7,7 @@
 
 #pragma once
 #include "error/error.h"
+#include "display/displaystate.h"
 
 typedef struct {
   SDL_Window *window;
@@ -29,6 +30,11 @@ errorret_t displaySDL2Update(void);
  */
 errorret_t displaySDL2Swap(void);
 
+/**
+ * Sets the SDL2 display state.
+ */
+errorret_t displaySDL2SetState(displaystate_t state);
+
 /**
  * Disposes/Cleans up the SDL2 Render system.
  */