skip switching texture modes when they're the same as the last used

src/rendering/twn_gl_15_rendering.c

@@ -147,6 +147,7 @@ typedef struct {
 } DeferredCommand;
 
 
+static TextureMode texture_mode_last_used = -1;
 static Pipeline pipeline_last_used = PIPELINE_NO;
 
 
@@ -401,6 +402,7 @@ static void finally_use_space_pipeline(void) {
     glMatrixMode(GL_MODELVIEW);
     glLoadMatrixf(&camera_look_at_matrix.row[0].x);
 
+    texture_mode_last_used = -1;
     pipeline_last_used = PIPELINE_SPACE;
 }
 
@@ -452,6 +454,7 @@ static void finally_use_2d_pipeline(void) {
     glMatrixMode(GL_MODELVIEW);
     glLoadIdentity();
 
+    texture_mode_last_used = -1;
     pipeline_last_used = PIPELINE_2D;
 }
 
@@ -501,6 +504,9 @@ void use_texture_mode(TextureMode mode) {
 
 
 static void finally_use_texture_mode(TextureMode mode) {
+    if (texture_mode_last_used == mode)
+        return;
+
     static GLuint lists = 0;
     if (!lists) {
         lists = glGenLists(3);
@@ -539,6 +545,8 @@ static void finally_use_texture_mode(TextureMode mode) {
     } else {
         glCallList(lists + 2);
     }
+
+    texture_mode_last_used = mode;
 }