Method render

src/backend/opengl/image_impl.cpp:135–199

uint image_impl::size() const { return (uint)mPBOsize; }

void image_impl::render(const int pWindowId,
                        const int pX, const int pY, const int pVPW, const int pVPH,
                        const glm::mat4 &pView, const glm::mat4 &pOrient)
{
    CheckGL("Begin image_impl::render");

    float xscale = 1.f;
    float yscale = 1.f;
    if (mKeepARatio) {
        if (mWidth > mHeight) {
            float trgtH = pVPW * float(mHeight)/float(mWidth);
            float trgtW = trgtH * float(mWidth)/float(mHeight);
            xscale = trgtW/pVPW;
            yscale = trgtH/pVPH;
        } else {
            float trgtW = pVPH * float(mWidth)/float(mHeight);
            float trgtH = trgtW * float(mHeight)/float(mWidth);
            xscale = trgtW/pVPW;
            yscale = trgtH/pVPH;
        }
    }

    glm::mat4 strans = glm::scale(pView, glm::vec3(xscale, yscale, 1));

    glDepthMask(GL_FALSE);
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    mProgram.bind();

    glUniform1i(mNumCIndex, gl::GLint(mFormatSize));
    glUniform1f(mAlphaIndex, mAlpha);

    // load texture from PBO
    glActiveTexture(GL_TEXTURE0);
    glUniform1i(mTexIndex, 0);
    glBindTexture(GL_TEXTURE_2D, mTex);
    // bind PBO to load data into texture
    glBindBuffer(GL_PIXEL_UNPACK_BUFFER, mPBO);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
    glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, mWidth, mHeight, mGLformat, mGLType, 0);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 4);

    glUniformMatrix4fv(mMatIndex, 1, GL_FALSE, glm::value_ptr(strans));

    glUniform1f(mCMapLenIndex, (GLfloat)mUBOSize);
    glBindBufferBase(GL_UNIFORM_BUFFER, 0, mColorMapUBO);
    glUniformBlockBinding(mProgram.getProgramId(), mCMapIndex, 0);

    // Draw to screen
    bindResources(pWindowId);
    glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
    unbindResources();

    glBindTexture(GL_TEXTURE_2D, 0);
    glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);

    // ubind the shader program