buttons can be drawn

Makefile

@@ -1,5 +1,12 @@
-build:
-	gcc mmn_17.c -lglut -lGL -lGLU -lm -o mmn_17
+OBJ = ui.o vec.o
+CFLAGS = -g -Wall
+
+build: $(OBJ)
+	gcc $(CFLAGS) mmn_17.c $(OBJ) -lglut -lGL -lGLU -lm -o mmn_17
+
+%.o : %.c
+		gcc -c $(CFLAGS) $< -o $@
+
 
 clean:
-	rm mmn_17
+	rm *.o mmn_17

mmn_17.c

@@ -1,13 +1,33 @@
 #include <GL/freeglut.h>
 #include <GL/freeglut_std.h>
 #include <GL/gl.h>
+#include <GL/glu.h>
 #include <stdio.h>
 #include <math.h>
+#include "ui.h"
+// Ui stuff
+ui_button buttons[] = {
+    { 
+            /* pos */ { { 0.5, 0.5, 0.0 }, { -50.0, -25.0, 0.0 } },
+            /* size */ { 100.0, 50.0, 0.0 },
+            /* onclick */ NULL,
+            /* text */ "Test :)"
+        }
+};
 
 void display(void) {
     // Clear screen
     glClearColor(0.0, 0.0, 0.0, 1.0); // Dark theme :)
     glClear(GL_COLOR_BUFFER_BIT);
+    // Draw buttons
+    for(ui_button* b = buttons; b < buttons + sizeof buttons / sizeof(ui_button); b += 1) {
+        ui_button_draw(b);
+    }
+    int err = glGetError();
+    if(err != 0) {
+        printf("opengl error %d: %s\n", err, gluErrorString(err));
+    }
+    glutSwapBuffers();
     glFlush();
 }
 
@@ -22,7 +42,7 @@ int main(int argc, char** argv) {
     glutInitWindowSize(800, 500);
     glutInitWindowPosition(450, 450);
     /* create window and set callbacks */
-    glutCreateWindow("glutLeaveMainLoop is undefined if called from a nested loop");
+    glutCreateWindow("World of Cow");
     glutDisplayFunc(display);
     glutMouseFunc(mouseEvent);
     

ui.c

@@ -0,0 +1,47 @@
+#include "ui.h"
+#include "vec.h"
+#include <GL/freeglut_std.h>
+#include <GL/freeglut_ext.h>
+#include <GL/glut.h>
+#include <GL/gl.h>
+#include <stdio.h>
+
+void ui_button_draw(ui_button* b) {
+    printf("drawing button %p\n", b);
+    int wWidth = glutGet(GLUT_WINDOW_WIDTH);
+    int wHeight = glutGet(GLUT_WINDOW_HEIGHT);
+    
+    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(1.0, 1.0, 1.0);
+    glBegin(GL_QUADS);
+        glVertexVec(pos);
+        glVertex3f(pos.x + ext.x, pos.y, pos.z);
+        glVertexVec(vec3_add(pos, ext));
+        glVertex3f(pos.x, pos.y + ext.y, pos.z);
+    glEnd();
+    // Draw text if needed
+    if(b->text != NULL) {
+        glColor3f(0.0, 0.0, 0.0);
+        // Get text size
+        int textWidth = glutBitmapLength(GLUT_BITMAP_TIMES_ROMAN_24, (unsigned char*)b->text);
+        int textHeight = glutBitmapHeight(GLUT_BITMAP_TIMES_ROMAN_24);
+        // set raster position - not gonna take into account multiple line text buttons
+        vec3 rPos = vec3_add(pos, vec3_mult(ext, 0.5));
+        rPos.x -= textWidth * 0.5;
+        rPos.y -= textHeight * 0.25;
+        glRasterPos3f(rPos.x, rPos.y, rPos.z);
+        glutBitmapString(GLUT_BITMAP_TIMES_ROMAN_24, (unsigned char*)b->text);
+    }
+}
+
+char ui_button_mouse_over(ui_button* b) {
+    return 0;
+}
+
+void ui_slider_draw(ui_slider* s) {
+    
+}
+char ui_slider_mouse_over(ui_slider* s) {
+    return 0;
+}

ui.h

@@ -1,12 +1,31 @@
-#ifndef  __UI_BUTTON
-#define __UI_BUTTON
+#ifndef  __UI
+#define __UI
 #include "vec.h"
 
+typedef struct _ui_position {
+    vec3 relative;
+    vec3 absolute;
+} ui_pos;
+
 typedef struct _ui_button {
-    vec3 relative; // Position relative to screen size
-    vec3 absolute; // position in pixels(added to relative)
+    ui_pos position;
+    /* x,y - width,height, z - unused */
     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;
 } ui_button;
 
+typedef struct _ui_slider {
+    ui_pos position;
+    /* x - width, y - height, z - middle circle radius */
+    vec3 size;
+    float value; // Value will always range between 0 and 1
+} ui_slider;
+
+void ui_button_draw(ui_button* b);
+char ui_button_mouse_over(ui_button* b);
+
+void ui_slider_draw(ui_slider* s);
+char ui_slider_mouse_over(ui_slider* s);
+
 #endif

ui_button.h

@@ -1,25 +0,0 @@
-#ifndef  __UI
-#define __UI
-#include "vec.h"
-
-typedef struct _ui_position {
-    vec3 relative;
-    vec3 absolute;
-} ui_pos;
-
-typedef struct _ui_button {
-    ui_pos position;
-    /* x,y - width,height, z - unused */
-    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;
-} ui_button;
-
-typedef struct _ui_slider {
-    ui_pos position;
-    /* x - width, y - height, z - middle circle radius */
-    vec3 size;
-    float value; // Value will always range between 0 and 1
-} ui_slider;
-
-#endif

vec.c

@@ -1,4 +1,5 @@
 #include "vec.h"
+#include <GL/gl.h>
 
 vec3 vec3_new(float x, float y, float z) {
     vec3 r = { x, y, z };
@@ -26,4 +27,11 @@ float vec3_dot(vec3 a, vec3 b) {
 vec3 vec3_mult(vec3 a, float s) {
     vec3 r = { a.x * s, a.y * s, a.z * s };
     return r;
+}
+
+void glVertexVec(vec3 v) {
+    glVertex3f(v.x, v.y, v.z);
+}
+void glColorVec(vec3 v) {
+    glColor3f(v.x, v.y, v.z);
 }

vec.h

@@ -7,8 +7,6 @@ typedef struct _vec3 {
     float z;
 } vec3;
 
-const vec3 ZERO = { 0.0, 0.0, 0.0};
-
 vec3 vec3_new(float x, float y, float z);
 vec3 vec3_splat(float f);
 vec3 vec3_add(vec3 a, vec3 b);
@@ -16,4 +14,8 @@ vec3 vec3_sub(vec3 a, vec3 b);
 float vec3_dot(vec3 a, vec3 b);
 vec3 vec3_mult(vec3 a, float s);
 
+// Some opengl extensions to support these vectors
+void glVertexVec(vec3 v);
+void glColorVec(vec3 v);
+
 #endif