//

// Copyright (c) 2014 The ANGLE Project Authors. All rights reserved.

// Use of this source code is governed by a BSD-style license that can be

// found in the LICENSE file.

//

// Based on TextureWrap.c from

// Book: OpenGL(R) ES 2.0 Programming Guide

// Authors: Aaftab Munshi, Dan Ginsburg, Dave Shreiner

// ISBN-10: 0321502795

// ISBN-13: 9780321502797

// Publisher: Addison-Wesley Professional

// URLs: http://safari.informit.com/9780321563835

// http://www.opengles-book.com

#include "SampleApplication.h"

#include "shader_utils.h"

#include "texture_utils.h"

class TextureWrapSample : public SampleApplication

{

public:

TextureWrapSample()

: SampleApplication("TextureWrap", 1280, 720)

{

}

virtual bool initialize()

{

const std::string vs = SHADER_SOURCE

(

uniform float u_offset;

attribute vec4 a_position;

attribute vec2 a_texCoord;

varying vec2 v_texCoord;

void main()

{

gl_Position = a_position;

gl_Position.x += u_offset;

v_texCoord = a_texCoord;

}

);

const std::string fs = SHADER_SOURCE

(

precision mediump float;

varying vec2 v_texCoord;

uniform sampler2D s_texture;

void main()

{

gl_FragColor = texture2D(s_texture, v_texCoord);

}

);

mProgram = CompileProgram(vs, fs);

if (!mProgram)

{

return false;

}

// Get the attribute locations

mPositionLoc = glGetAttribLocation(mProgram, "a_position");

mTexCoordLoc = glGetAttribLocation(mProgram, "a_texCoord");

// Get the sampler location

mSamplerLoc = glGetUniformLocation(mProgram, "s_texture");

// Get the offset location

mOffsetLoc = glGetUniformLocation(mProgram, "u_offset");

// Load the texture

mTexture = CreateMipMappedTexture2D();

glClearColor(0.0f, 0.0f, 0.0f, 0.0f);

return true;

}

virtual void destroy()

{

glDeleteProgram(mProgram);

}

virtual void draw()

{

GLfloat vertices[] =

{

-0.3f, 0.3f, 0.0f, 1.0f, // Position 0

-1.0f, -1.0f, // TexCoord 0

-0.3f, -0.3f, 0.0f, 1.0f, // Position 1

-1.0f, 2.0f, // TexCoord 1

0.3f, -0.3f, 0.0f, 1.0f, // Position 2

2.0f, 2.0f, // TexCoord 2

0.3f, 0.3f, 0.0f, 1.0f, // Position 3

2.0f, -1.0f // TexCoord 3

};

GLushort indices[] = { 0, 1, 2, 0, 2, 3 };

// Set the viewport

glViewport(0, 0, getWindow()->getWidth(), getWindow()->getHeight());

// Clear the color buffer

glClear(GL_COLOR_BUFFER_BIT);

// Use the program object

glUseProgram(mProgram);

// Load the vertex position

glVertexAttribPointer(mPositionLoc, 4, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat), vertices);

glEnableVertexAttribArray(mPositionLoc);

// Load the texture coordinate

glVertexAttribPointer(mTexCoordLoc, 2, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat), vertices + 4);

glEnableVertexAttribArray(mTexCoordLoc);

// Set the sampler texture unit to 0

glUniform1i(mSamplerLoc, 0);

// Draw quad with repeat wrap mode

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

glUniform1f(mOffsetLoc, -0.7f);

glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, indices);

// Draw quad with clamp to edge wrap mode

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

glUniform1f(mOffsetLoc, 0.0f);

glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, indices);

// Draw quad with mirrored repeat

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_MIRRORED_REPEAT);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_MIRRORED_REPEAT);

glUniform1f(mOffsetLoc, 0.7f);

glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, indices);

}

private:

// Handle to a program object

GLuint mProgram;

// Attribute locations

GLint mPositionLoc;

GLint mTexCoordLoc;

// Sampler location

GLint mSamplerLoc;

// Offset location

GLint mOffsetLoc;

// Texture handle

GLuint mTexture;

};

int main(int argc, char **argv)

{

TextureWrapSample app;

return app.run();

}