I am learning open GL ES 2.0 and I just made 1 easy game for 1.0
I am following tutorials but I cant understand this thing
In OpenGL ES 1.0 if I define a square that way:
private float[] vertices = { // Vertices for a face 0.0f, 0.0f, 0.2f, // 0. left-bottom-front 1.0f, 0.0f, 0.2f, // 1. right-bottom-front 0.0f, 1.0f, 0.2f, // 2. left-top-front 1.0f, 1.0f, 0.2f // 3. right-top-front }; and draw it that way it Works
public void draw(GL10 gl) { gl.glFrontFace(GL10.GL_CCW); // Front face in counter-clockwise // orientation gl.glEnable(GL10.GL_CULL_FACE); // Enable cull face gl.glCullFace(GL10.GL_BACK); // Cull the back face (don't display) gl.glEnableClientState(GL10.GL_VERTEX_ARRAY); gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer); gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY); // Enable // texture-coords-array // (NEW) gl.glTexCoordPointer(3, GL10.GL_FLOAT, 0, texBuffer); // Define // texture-coords // buffer (NEW) gl.glEnable(GL10.GL_BLEND); gl.glBlendFunc(GL10.GL_SRC_ALPHA, GL10.GL_ONE_MINUS_SRC_ALPHA); // front gl.glBindTexture(GL10.GL_TEXTURE_2D,TextureLoader.TeclaBlancatextureIDs[0]); gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4); gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY); // Disable // texture-coords-array // (NEW) gl.glDisableClientState(GL10.GL_VERTEX_ARRAY); gl.glDisable(GL10.GL_CULL_FACE); gl.glDisable(GL10.GL_BLEND); } but in OpenGL ES 2.0 if I do this that way( with the same vertex) it only write a triangle:
private void drawSuelo(Suelo suelo) { // Pass in the position information suelo.mPositions.position(0); GLES20.glVertexAttribPointer(mPositionHandle, mPositionDataSize, GLES20.GL_FLOAT, false, 0, suelo.mPositions); GLES20.glEnableVertexAttribArray(mPositionHandle); // Pass in the color information suelo.mColors.position(0); GLES20.glVertexAttribPointer(mColorHandle, mColorDataSize, GLES20.GL_FLOAT, false, 0, suelo.mColors); GLES20.glEnableVertexAttribArray(mColorHandle); // Pass in the normal information cubo.mCubeNormals.position(0); GLES20.glVertexAttribPointer(mNormalHandle, mNormalDataSize, GLES20.GL_FLOAT, false, 0, cubo.mCubeNormals); GLES20.glEnableVertexAttribArray(mNormalHandle); // This multiplies the view matrix by the model matrix, and stores the result in the MVP matrix // (which currently contains model * view). Matrix.multiplyMM(mMVPMatrix, 0, mViewMatrix, 0, mModelMatrix, 0); // Pass in the modelview matrix. GLES20.glUniformMatrix4fv(mMVMatrixHandle, 1, false, mMVPMatrix, 0); // This multiplies the modelview matrix by the projection matrix, and stores the result in the MVP matrix // (which now contains model * view * projection). Matrix.multiplyMM(mMVPMatrix, 0, mProjectionMatrix, 0, mMVPMatrix, 0); // Pass in the combined matrix. GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false, mMVPMatrix, 0); // Pass in the light position in eye space. GLES20.glUniform3f(mLightPosHandle, mLightPosInEyeSpace[0], mLightPosInEyeSpace[1], mLightPosInEyeSpace[2]); // Draw the cube. GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, 6); } It seems to need all of this vertex in order to draw a square
final float[] PositionData = { // Top face -1.0f, 1.0f, -1.0f, -1.0f, 1.0f, 1.0f, 1.0f, 1.0f, -1.0f, -1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, -1.0f }; Why is happening this? Why I am missing? Is there any way in Open GL ES 2.0 to write a square with 4 vertex?
