world_of_cow/ui.c

#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>

#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);
    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;
    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);
        glVertexVec(vec3_add(pos, ext));
        glVertex3f(pos.x, pos.y + ext.y, pos.z);
    glEnd();
    glColor3f(0.7, 0.7, 0.8);
    glLineWidth(2.0);
    glBegin(GL_LINE_LOOP);
        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(1.0, 1.0, 1.0);
        // 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, int mouseX, int mouseY) {
    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;
    vec3 m = vec3_sub(vec3_new(mouseX, wHeight - mouseY, 0.0), pos);
    return m.x > 0.0 && m.x < ext.x && m.y > 0.0 && m.y < ext.y;
}

void ui_slider_draw(ui_slider* s) {
    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));
    vec3 ext = s->size;
    
    vec3 slider = vec3_add(pos, vec3_new(ext.x * s->value, ext.y * 0.5, 0.0));
    glBegin(GL_QUADS);
        // draw background line
        glColor3f(BACK_COLOR);
        glVertexVec(pos);
        glVertex3f(pos.x + ext.x, pos.y, pos.z);
        glVertex3f(pos.x + ext.x, pos.y + ext.y, pos.z);
        glVertex3f(pos.x, pos.y + ext.y, pos.z);
        // Draw slider button thing
        glColor3f(1.0, 1.0, 1.0);
        glVertex3f(slider.x - ext.z, slider.y - ext.z, 0.0);
        glVertex3f(slider.x + ext.z, slider.y - ext.z, 0.0);
        glVertex3f(slider.x + ext.z, slider.y + ext.z, 0.0);
        glVertex3f(slider.x - ext.z, slider.y + ext.z, 0.0);
    glEnd();
}

char ui_slider_mouse_over(ui_slider* s, int mouseX, int mouseY) {
    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));
    vec3 ext = s->size;
    vec3 m = vec3_sub(vec3_new(mouseX, wHeight - mouseY - 0.5 * ext.y, 0.0), pos);
    return m.x > 0.0 && m.x < ext.x && m.y > -ext.z && m.y < ext.z;
}

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;
}