Android OpenGL ES 2.0 w/ Native Code Outputs Black Screen

Question

I'm about to head to bed, but I've been scratching my head at this for the past 6 hours or so, and after numerous small "ooh that has to be the problem!"s, I'm officially sleepy and out of clues.

PROJECT SOURCE

The project runs on android, and at this point should display a sphere on the screen moving. I tested the code, and everything SHOULD work! The only part I'm even slightly iffy on is the rendering and set up code for OpenGL ES 2.0:

Setup Code:

glGenBuffers(1, &vb);
glBindBuffer(GL_ARRAY_BUFFER, vb);
glBufferData(GL_ARRAY_BUFFER, DragonMesh->numVerts*12, 
                    (GLvoid*)verts, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);

glGenBuffers(1, &ib);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ib);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, DragonMesh->numTris*6,
                    (GLvoid*)DragonMesh->vertIndices, GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);

Render Code:

glUseProgram(Shader->tech);

float col[] = {1.f, 0.f, 0.f, 1.0f};
glUniformMatrix4fv(Shader->mvpMatrix, 1, GL_FALSE, 
                    (GLfloat*)ModelViewProjection.m);
glUniform4fv(Shader->color, 1, col);

glBindBuffer(GL_ARRAY_BUFFER, vb);

glVertexAttribPointer(Shader->position, 3, GL_FLOAT, GL_FALSE, 12, 0);
glEnableVertexAttribArray(Shader->position);

glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ib);

glDrawElements(GL_TRIANGLES, DragonMesh->numTris*3, GL_UNSIGNED_SHORT, 0);

glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);

where ModelViewProjection.m is a float[4][4], and verts is a float pointer, pointing to a bunch of contiguous values that make up the coords for each position.

I set up my shaders correctly, linking and building them with no errors (I checked for errors using OpenGL's related error checking calls).

I also thought it might be my device (an LG Optimus S running 2.3.3, but the phone says it supports OpenGL-ES 2.0).

Anyway, when I run it, there's just a black screen.

If you can help me at all, I'd be so thankful.

EDIT: Fixed parameter of GL_UNSIGNED_INT instead of GL_UNSIGNED_SHORT (Problem still persists though sadly).

EDIT2: I have a clue! I'll try it when I get home from work, but I'm not converting to radians from degrees when calculating my projection - and that's a bad thing. A very bad thing.

EDIT3: Nope

EDIT4: I've updated the repo quite a bit, adding error checks at every corner and fixing some bugs along the way. The screen is still black however... If anyone stumbles across this I highly recommend checking the repo, since black screens could mean anything. Thanks again to anybody taking the time to read this! (I also realized I left some temp changes like vertical fov = 0, and center/eye having same pos. Ignore those for now).

EDIT5: Realized I'm possibly multiplying my Eye translation by the LookAt transform in the wrong order. I'll check it out around 6pm when I get back from work.

THAT WAS IT!!! I've been stuck with a black screen for weeks, and it's because I was multiplying a translation in the wrong order. If anyone stumbles across this looking to fix a black screen, the guy who commented on this post has a blog with an entry containing a list of common black-screen causing things. It should help you out.

If not, check your matrices and make sure you're doing everything in the right order :)

Answer 1

I was multiplying a matrix with another in the wrong order, as is tradition