/*
 * Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com
 *
 * iPhone port by Simon Oliver - http://www.simonoliver.com - http://www.handcircus.com
 *
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 * 1. The origin of this software must not be misrepresented; you must not
 * claim that you wrote the original software. If you use this software
 * in a product, an acknowledgment in the product documentation would be
 * appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 * misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 */

#include "GLES-Render.h"
#include "cocos2d.h"
#include <stdio.h>
#include <stdarg.h>
#include <string.h>

USING_NS_CC;

GLESDebugDraw::GLESDebugDraw()
    : mRatio( 1.0f )
{
    this->initShader();
}

GLESDebugDraw::GLESDebugDraw( float32 ratio )
    : mRatio( ratio )
{
    this->initShader();
}

void GLESDebugDraw::initShader( void )
{
    mShaderProgram = GLProgramCache::getInstance()->getGLProgram(GLProgram::SHADER_NAME_POSITION_U_COLOR);

    mColorLocation = glGetUniformLocation( mShaderProgram->getProgram(), "u_color");
}

void GLESDebugDraw::DrawPolygon(const b2Vec2* old_vertices, int vertexCount, const b2Color& color)
{
    mShaderProgram->use();
    mShaderProgram->setUniformsForBuiltins();

    b2Vec2* vertices = new b2Vec2[vertexCount];
    for( int i=0;i<vertexCount;i++) 
    {
        vertices[i] = old_vertices[i];
        vertices[i] *= mRatio;
    }

    mShaderProgram->setUniformLocationWith4f(mColorLocation, color.r, color.g, color.b, 1);

    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION, 2, GL_FLOAT, GL_FALSE, 0, vertices);
    glDrawArrays(GL_LINE_LOOP, 0, vertexCount);

    CC_INCREMENT_GL_DRAWN_BATCHES_AND_VERTICES(1,vertexCount);


    CHECK_GL_ERROR_DEBUG();

    delete[] vertices;
}

void GLESDebugDraw::DrawSolidPolygon(const b2Vec2* old_vertices, int vertexCount, const b2Color& color)
{
    mShaderProgram->use();
    mShaderProgram->setUniformsForBuiltins();

    b2Vec2* vertices = new b2Vec2[vertexCount];
    for( int i=0;i<vertexCount;i++) {
        vertices[i] = old_vertices[i];
        vertices[i] *= mRatio;
    }
    
    mShaderProgram->setUniformLocationWith4f(mColorLocation, color.r*0.5f, color.g*0.5f, color.b*0.5f, 0.2f);

    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION, 2, GL_FLOAT, GL_FALSE, 0, vertices);

    glDrawArrays(GL_TRIANGLE_FAN, 0, vertexCount);

    mShaderProgram->setUniformLocationWith4f(mColorLocation, color.r, color.g, color.b, 1);
    glDrawArrays(GL_LINE_LOOP, 0, vertexCount);

    CC_INCREMENT_GL_DRAWN_BATCHES_AND_VERTICES(2,vertexCount*2);

    CHECK_GL_ERROR_DEBUG();

    delete[] vertices;
}

void GLESDebugDraw::DrawCircle(const b2Vec2& center, float32 radius, const b2Color& color)
{
    mShaderProgram->use();
    mShaderProgram->setUniformsForBuiltins();

    const float32 k_segments = 16.0f;
    int vertexCount=16;
    const float32 k_increment = 2.0f * b2_pi / k_segments;
    float32 theta = 0.0f;
    
    GLfloat*    glVertices = new GLfloat[vertexCount*2];
    for (int i = 0; i < k_segments; ++i)
    {
        b2Vec2 v = center + radius * b2Vec2(cosf(theta), sinf(theta));
        glVertices[i*2]=v.x * mRatio;
        glVertices[i*2+1]=v.y * mRatio;
        theta += k_increment;
    }
    
    mShaderProgram->setUniformLocationWith4f(mColorLocation, color.r, color.g, color.b, 1);
    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION, 2, GL_FLOAT, GL_FALSE, 0, glVertices);

    glDrawArrays(GL_LINE_LOOP, 0, vertexCount);

    CC_INCREMENT_GL_DRAWN_BATCHES_AND_VERTICES(1,vertexCount);

    CHECK_GL_ERROR_DEBUG();

    delete[] glVertices;
}

void GLESDebugDraw::DrawSolidCircle(const b2Vec2& center, float32 radius, const b2Vec2& axis, const b2Color& color)
{
    mShaderProgram->use();
    mShaderProgram->setUniformsForBuiltins();

    const float32 k_segments = 16.0f;
    int vertexCount=16;
    const float32 k_increment = 2.0f * b2_pi / k_segments;
    float32 theta = 0.0f;
    
    GLfloat*    glVertices = new GLfloat[vertexCount*2];
    for (int i = 0; i < k_segments; ++i)
    {
        b2Vec2 v = center + radius * b2Vec2(cosf(theta), sinf(theta));
        glVertices[i*2]=v.x * mRatio;
        glVertices[i*2+1]=v.y * mRatio;
        theta += k_increment;
    }
    
    mShaderProgram->setUniformLocationWith4f(mColorLocation, color.r*0.5f, color.g*0.5f, color.b*0.5f, 0.2f);
    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION, 2, GL_FLOAT, GL_FALSE, 0, glVertices);
    glDrawArrays(GL_TRIANGLE_FAN, 0, vertexCount);


    mShaderProgram->setUniformLocationWith4f(mColorLocation, color.r, color.g, color.b, 1);
    glDrawArrays(GL_LINE_LOOP, 0, vertexCount);

    // Draw the axis line
    DrawSegment(center,center+radius*axis,color);

    CC_INCREMENT_GL_DRAWN_BATCHES_AND_VERTICES(2,vertexCount*2);

    CHECK_GL_ERROR_DEBUG();

    delete[] glVertices;
}

void GLESDebugDraw::DrawSegment(const b2Vec2& p1, const b2Vec2& p2, const b2Color& color)
{
    mShaderProgram->use();
    mShaderProgram->setUniformsForBuiltins();

    mShaderProgram->setUniformLocationWith4f(mColorLocation, color.r, color.g, color.b, 1);

    GLfloat    glVertices[] = 
    {
        p1.x * mRatio, p1.y * mRatio,
        p2.x * mRatio, p2.y * mRatio
    };
    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION, 2, GL_FLOAT, GL_FALSE, 0, glVertices);

    glDrawArrays(GL_LINES, 0, 2);

    CC_INCREMENT_GL_DRAWN_BATCHES_AND_VERTICES(1,2);

    CHECK_GL_ERROR_DEBUG();
}

void GLESDebugDraw::DrawTransform(const b2Transform& xf)
{
    b2Vec2 p1 = xf.p, p2;
    const float32 k_axisScale = 0.4f;
    p2 = p1 + k_axisScale * xf.q.GetXAxis();
    DrawSegment(p1, p2, b2Color(1,0,0));

    p2 = p1 + k_axisScale * xf.q.GetYAxis();
    DrawSegment(p1,p2,b2Color(0,1,0));
}

void GLESDebugDraw::DrawPoint(const b2Vec2& p, float32 size, const b2Color& color)
{
    mShaderProgram->use();
    mShaderProgram->setUniformsForBuiltins();

    mShaderProgram->setUniformLocationWith4f(mColorLocation, color.r, color.g, color.b, 1);

    //    glPointSize(size);

    GLfloat                glVertices[] = {
        p.x * mRatio, p.y * mRatio
    };

    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION, 2, GL_FLOAT, GL_FALSE, 0, glVertices);

    glDrawArrays(GL_POINTS, 0, 1);
    //    glPointSize(1.0f);

    CC_INCREMENT_GL_DRAWN_BATCHES_AND_VERTICES(1,1);

    CHECK_GL_ERROR_DEBUG();
}

void GLESDebugDraw::DrawString(int x, int y, const char *string, ...)
{
//    NSLog(@"DrawString: unsupported: %s", string);
    //printf(string);
    /* Unsupported as yet. Could replace with bitmap font renderer at a later date */
}

void GLESDebugDraw::DrawAABB(b2AABB* aabb, const b2Color& color)
{
    mShaderProgram->use();
    mShaderProgram->setUniformsForBuiltins();

    mShaderProgram->setUniformLocationWith4f(mColorLocation, color.r, color.g, color.b, 1);

    GLfloat                glVertices[] = {
        aabb->lowerBound.x * mRatio, aabb->lowerBound.y * mRatio,
        aabb->upperBound.x * mRatio, aabb->lowerBound.y * mRatio,
        aabb->upperBound.x * mRatio, aabb->upperBound.y * mRatio,
        aabb->lowerBound.x * mRatio, aabb->upperBound.y * mRatio
    };

    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION, 2, GL_FLOAT, GL_FALSE, 0, glVertices);
    glDrawArrays(GL_LINE_LOOP, 0, 4);

    CC_INCREMENT_GL_DRAWN_BATCHES_AND_VERTICES(1,4);

    CHECK_GL_ERROR_DEBUG();
}