opengl-es

This is my scenario: I am trying to take a picture from the front camera when someone puts in the incorrect password in the lock screen. Basically, I need to be able to take a picture out of the front cam without a preview. After much googling, I figured out that the way to do it is opengl and SurfaceTexture. You direct the camera preview to a SurfaceTexture, and later extract the picture from this texture somehow. I found this out from the following resources: https://stackoverflow.com/a/10776349/902572 (suggestion 1) http://www.freelancer.com/projects/Android-opengl/Android-OpenGL-App-Access

Im having trouble displaying pixel based art (think retro tiles and art) on OpenGL Es 1.1 on the iPhones. Tiles are represented using 8bytes (1 byte for each row) with each bit representing a pixel being set or not. For example a tile with the number 8: 0 0 0 0 0 0 0 0 -> 0 0 1 1 1 0 0 0 -> xxx 0 1 0 0 0 1 0 0 -> x x 0 1 0 0 0 1 0 0 -> x x 0 0 1 1 1 0 0 0 -> xxx 0 1 0 0 0 1 0 0 -> x x 0 1 0 0 0 1 0 0 -> x x 0 0 1 1 1 0 0 0 -> xxx Converting this to OpenGL on iPhone using glDrawArrays(GL_POINTS, 0, 64); The logic is correct, but the problem is it doesn't give the retro effect. I was looking for

I get a fill rate of about 30fps in my application. I know that GLES20.glClear() is used to clear the screen for every draw. If i comment it i get a fps of about 60fps. But the output is not as expected. I have a content to be redrawn for the whole screen in every frame. Is there any alternative where i can redraw the whole screen with out using the GLES20.glClear(). Please let me know if there is any way to play around with GLES20.glClear() to improve the performance? If you overwrite the entire color buffer with your geometry each frame you can get away with just clearing the depth buffer.

I'm trying to replace OpenGL's gl_FragDepth feature which is missing in OpenGL ES 2.0. I need a way to set the depth in the fragment shader, because setting it in the vertex shader is not accurate enough for my purpose. AFAIK the only way to do that is by having a render-to-texture framebuffer on which a first rendering pass is done. This depth texture stores the depth values for each pixel on the screen. Then, the depth texture is attached in the final rendering pass, so the final renderer knows the depth at each pixel. Since iOS >= 4.1 supports GL_OES_depth_texture , I'm trying to use GL

I have an iPhone app that uses too much texture memory. I am trying to figure out which of the app's CALayers uses too much texture memory. Unfortunately, I cannot figure out how much texture memory a specific CALayer is using. Are there any good tricks I can use ? 来源： https://stackoverflow.com/questions/8214884/calayer-opengl-es-texture-memory-usage

as you know that AVFrame has 2 property:pFrame->data, pFrame->linesize. After i read frame from video /sdcard/test.mp4 (android platform), and convert to RGB AVFrame vice: img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, target_width, target_height, PIX_FMT_RGB24, SWS_BICUBIC, NULL, NULL, NULL); if(img_convert_ctx == NULL) { LOGE("could not initialize conversion context\n"); return; } sws_scale(img_convert_ctx, (const uint8_t* const*)pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize); I get pFrameRGB after