buttons darnek when held and sliders can be controlled through mouse

mmn_17.c

@@ -7,16 +7,18 @@
 #include <math.h>
 #include "ui.h"
 
-void testButtonClick();
-
+int lastMouseButton = GLUT_LEFT_BUTTON;
+ui_slider* draggedSlider = NULL;
 
 // Ui stuff
+void testButtonClick();
 ui_button buttons[] = {
     { 
             /* pos */ { { 0.5, 0.5, 0.0 }, { -50.0, -25.0, 0.0 } },
             /* size */ { 100.0, 50.0, 0.0 },
             /* onclick */ testButtonClick,
-            /* text */ "Test :)"
+            /* text */ "Test :)",
+            0
         }
 };
 ui_slider sliders[] = {
@@ -98,20 +100,42 @@ void display(void) {
 }
 
 void mouseEvent(int button, int state, int x, int y) {
-    if(state == 0) {
+    if(state == 0) lastMouseButton = button;
+    if(state == 0 && button == GLUT_LEFT_BUTTON) {
         for(ui_button* b = buttons; b < buttons + sizeof buttons / sizeof(ui_button); b += 1) {
             if(ui_button_mouse_over(b, x, y) && b->onClick != NULL) {
-                b->onClick();
-                return;
-            }
+                b->clicked = 1;
             }
         }
         for(ui_slider* s = sliders; s < sliders + sizeof sliders / sizeof(ui_slider); s += 1) {
             if(ui_slider_mouse_over(s, x, y)) {
-            ui_slider_onclick(s, x, y, button, state);
+                ui_slider_onclick(s, x, y);
+                draggedSlider = s;
             }
         }
     }
+    else if(state == 1 && button == GLUT_LEFT_BUTTON) {
+        draggedSlider = NULL;
+        for(ui_button* b = buttons; b < buttons + sizeof buttons / sizeof(ui_button); b += 1) {
+            b->clicked = 0;
+            if(ui_button_mouse_over(b, x, y) && b->onClick != NULL) {
+                b->onClick();
+            }
+        }
+    }
+    glutPostRedisplay();
+}
+
+void mouseMotionEvent(int x, int y) {
+    if(lastMouseButton == GLUT_LEFT_BUTTON) {
+        if(draggedSlider != NULL) {
+            if(ui_slider_mouse_over(draggedSlider, x, y)) {
+                ui_slider_onclick(draggedSlider, x, y);
+            }
+        }
+    }
+    glutPostRedisplay();
+}
 
 void mouseWheelEvent(int wheel, int dir, int x, int y) {
     for(ui_slider* s = sliders; s < sliders + sizeof sliders / sizeof(ui_slider); s += 1) {
@@ -147,6 +171,7 @@ int main(int argc, char** argv) {
     glutMouseFunc(mouseEvent);
     glutKeyboardFunc(keyboardEvent);
     glutMouseWheelFunc(mouseWheelEvent);
+    glutMotionFunc(mouseMotionEvent);
     
     /* set projection and camera */
     glMatrixMode(GL_PROJECTION);

ui.c

@@ -7,6 +7,7 @@
 #include <stdio.h>
 
 #define BACK_COLOR 0.3, 0.35, 0.35
+#define BACK_CLICKED_COLOR 0.25, 0.3, 0.3
 
 void ui_button_draw(ui_button* b) {
     int wWidth = glutGet(GLUT_WINDOW_WIDTH);
@@ -14,7 +15,7 @@ void ui_button_draw(ui_button* b) {
     
     vec3 pos = vec3_add(b->position.absolute, vec3_new(b->position.relative.x * wWidth, b->position.relative.y * wHeight, 0.0));
     vec3 ext = b->size;
-    glColor3f(BACK_COLOR);
+    glColorVec(b->clicked ? vec3_new(BACK_CLICKED_COLOR) : vec3_new(BACK_COLOR));
     glBegin(GL_QUADS);
         glVertexVec(pos);
         glVertex3f(pos.x + ext.x, pos.y, pos.z);
@@ -89,6 +90,11 @@ char ui_slider_mouse_over(ui_slider* s, int mouseX, int mouseY) {
     return m.x > 0.0 && m.x < ext.x && m.y > 0.0 && m.y < ext.y;
 }
 
-void ui_slider_onclick(ui_slider* s, int mouseX, int mouseY, int button, int state) {
+void ui_slider_onclick(ui_slider* s, int mouseX, int mouseY) {
+    // we assume mouse  is already hovering
+    int wWidth = glutGet(GLUT_WINDOW_WIDTH);
+    int wHeight = glutGet(GLUT_WINDOW_HEIGHT);
     
+    vec3 pos = vec3_add(s->position.absolute, vec3_new(s->position.relative.x * wWidth, s->position.relative.y * wHeight, 0.0));
+    s->value = ((float)mouseX - pos.x) / s->size.x;
 }

ui.h

@@ -13,6 +13,7 @@ typedef struct _ui_button {
     vec3 size; // size in pixels - if screen is too small i am not sure if it is a smart idea to make everything smaller
     void (*onClick)(); // instead of passing stuff in, im just gonna put every state variable in global scope to ensure everything lives...
     char* text;
+    char clicked;
 } ui_button;
 
 typedef struct _ui_slider {
@@ -27,6 +28,6 @@ char ui_button_mouse_over(ui_button* b, int mouseX, int mouseY);
 
 void ui_slider_draw(ui_slider* s);
 char ui_slider_mouse_over(ui_slider* s, int mouseX, int mouseY);
-void ui_slider_onclick(ui_slider* s, int mouseX, int mouseY, int button, int state);
+void ui_slider_onclick(ui_slider* s, int mouseX, int mouseY);
 
 #endif