[Solved] Texture mapping in cocos2dx 3.2

cocos2d-x C++
#1

Hi

I’m working on a project where I map an png image with openGL to a number of points (Vertex).
I override the draw method with following code which works fine on cocos3dx v3.0 but now when I update to 3.2 no image is shown.

Works fine in 3.0:

void JellyLogic::draw(Renderer *renderer, const kmMat4 &transform, bool transformUpdated) {
    kmGLPushMatrix();
    GL::bindTexture2D(texture->getName());
    texture->getShaderProgram()->use();
    texture->getShaderProgram()->setUniformsForBuiltins();
    GL::enableVertexAttribs(GL::VERTEX_ATTRIB_FLAG_POSITION | GL::VERTEX_ATTRIB_FLAG_TEX_COORDS);
    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION, 2, GL_FLOAT, GL_FALSE, 0, triangleStripPos);
    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_TEX_COORDS, 2, GL_FLOAT, GL_FALSE, 0, textCoords);
    glDrawArrays(GL_TRIANGLE_STRIP, 0,  NUM_VERTEX);
    kmGLPopMatrix();
}

I guess I need to change the texture->getShaderProgram()->use() to texture->getGlProgram()->use() in 3.2
The code compiles fine but no images is showing.

What have I missed? Why does not the image show in version 3.2?

#2

Do you have a screenshot of when it works and when i doesn’t?

#3

I don’t have a screenshot at the moment but, it is just a black screen in 3.2. There is no problem drawing ordinary sprite nodes or tiledMap.

#4

ok, I wanted to test this, what is texture, triangleStripPos, textCoords, NUM_VERTEX

#5

Thanks for helping

Texture:

texture = Director::getInstance()->getTextureCache()->addImage("green.png");

triangleStripPos:

typedef struct {
    GLfloat x;
    GLfloat y;
} Vertex2D;    

Vertex2D triangleStripPos[13];

textCoords:

Vertex2D textCoords[13];

NUM_VERTEX:

#define NUM_VERTEX 13

I’m mapping a square png-image with 9 points (3 x 3). This square is then made jelly-ish using soft physics.

#6

Sure, I’ll work with this.

In 3.3, latest from GitHub, so car I am doing:

void HelloWorld::draw(cocos2d::Renderer* renderer, const cocos2d::Mat4 &transform, bool transformUpdated)
{
    kmGLPushMatrix();
    GL::bindTexture2D(texture->getName());
    texture->getGLProgram()->use();
    texture->getGLProgram()->setUniformsForBuiltins();
    GL::enableVertexAttribs(GL::VERTEX_ATTRIB_FLAG_POSITION | GL::VERTEX_ATTRIB_FLAG_TEX_COORD);
    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION, 2, GL_FLOAT, GL_FALSE, 0, triangleStripPos);
    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_TEX_COORDS, 2, GL_FLOAT, GL_FALSE, 0, textCoords);
    glDrawArrays(GL_TRIANGLE_STRIP, 0,  NUM_VERTEX);
    kmGLPopMatrix();
}

Nothing is showing for me. I’ll need to try 3.2 and 3.1 etc to see what they produce.

#7

Since this question appears quite frequently Cocos2d-x devs or maintainers probably should create a sticked post here which informs that Cocos2d-x uses a command queue to render nodes and thus custom drawing routines should be wrapped with the command.

#8

Do you have any code samples or examples that shows this wrapping?

#9

There are definitely some examples in cocos2d-x\tests\cpp-tests. Try searching for command in cpp files.

#10

so we need to use customCommand to do this.

CustomCommand _customCommand; // in header or wherever makes sense for you

 _customCommand.init(_globalZOrder);

_customCommand.func = CC_CALLBACK_0(JellyLogic::onDraw, this, transform, flags);

renderer->addCommand(&_customCommand);

create JellyLogic::onDraw(...) and put that code above in it.

Thanks @dotsquid for the reminder.

#11

Work like a charm!

Thanks

#12

Just wanted to post the working code sample:

void JellyLogic::draw(Renderer *renderer, const Mat4 &transform, uint32_t flags)
{
    _customCommand.init(_globalZOrder);
    _customCommand.func = CC_CALLBACK_0(JellyLogic::onDraw, this, transform, flags);
    renderer->addCommand(&_customCommand);
}

void JellyLogic::onDraw(const Mat4 &transform, uint32_t flags) {
    kmGLPushMatrix();
    GL::bindTexture2D(texture->getName());
    texture->getGLProgram()->use();
    texture->getGLProgram()->setUniformsForBuiltins();
    GL::enableVertexAttribs(GL::VERTEX_ATTRIB_FLAG_POSITION | GL::VERTEX_ATTRIB_FLAG_TEX_COORD);
    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_POSITION, 2, GL_FLOAT, GL_FALSE, 0, triangleStripPos);
    glVertexAttribPointer(GLProgram::VERTEX_ATTRIB_TEX_COORDS, 2, GL_FLOAT, GL_FALSE, 0, textCoords);
    glDrawArrays(GL_TRIANGLE_STRIP, 0,  NUM_VERTEX);
    kmGLPopMatrix();
}
#13

great!! Glad you are working now!

#14

Only one problem… the images is showing in the bottom-left corner even though it is positioned some where else. I guess this has something to do with one of the flags.

EDIT: My bad, I messed up with the positioning. Everything works as it should :slight_smile:

#15

I have a problem when moving around my screen, custom drawing always stays in same position,
how to fix this ?

EDIT: forgot to set matrix, here is the code
glProgram->use();
glProgram->setUniformsForBuiltins(transform);