texture_wrap

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Author : Stuart Morgan
Date : 2019-08-14 12:25:12
Hash : 9d737966
Message : Standardize copyright notices to project style For all "ANGLE Project" copyrights, standardize to the format specified by the style guide. Changes: - "Copyright (c)" and "Copyright(c)" changed to just "Copyright". - Removed the second half of date ranges ("Y1Y1-Y2Y2"->"Y1Y1"). - Fixed a small number of files that had no copyright date using the initial commit year from the version control history. - Fixed one instance of copyright being "The ANGLE Project" rather than "The ANGLE Project Authors" These changes are applied both to the copyright of source file, and where applicable to copyright statements that are generated by templates. BUG=angleproject:3811 Change-Id: I973dd65e4ef9deeba232d5be74c768256a0eb2e5 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1754397 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>

TextureWrap.cpp

//
// Copyright 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 "texture_utils.h"
#include "util/shader_utils.h"

class TextureWrapSample : public SampleApplication
{
  public:
    TextureWrapSample(int argc, char **argv) : SampleApplication("TextureWrap", argc, argv) {}

    bool initialize() override
    {
        constexpr char kVS[] = R"(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;
})";

        constexpr char kFS[] = R"(precision mediump float;
varying vec2 v_texCoord;
uniform sampler2D s_texture;
void main()
{
    gl_FragColor = texture2D(s_texture, v_texCoord);
})";

        mProgram = CompileProgram(kVS, kFS);
        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;
    }

    void destroy() override { glDeleteProgram(mProgram); }

    void draw() override
    {
        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(argc, argv);
    return app.run();
}

kc3-lang/angle/samples/texture_wrap

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kc3-lang/angle /samples/texture_wrap