diff options
Diffstat (limited to 'gpu')
| -rw-r--r-- | gpu/command_buffer/client/gles2_implementation.cc | 26 |
1 files changed, 21 insertions, 5 deletions
diff --git a/gpu/command_buffer/client/gles2_implementation.cc b/gpu/command_buffer/client/gles2_implementation.cc index 99938d5..4eb6577 100644 --- a/gpu/command_buffer/client/gles2_implementation.cc +++ b/gpu/command_buffer/client/gles2_implementation.cc @@ -640,8 +640,6 @@ void GLES2Implementation::GetUniformiv( void GLES2Implementation::ReadPixels( GLint xoffset, GLint yoffset, GLsizei width, GLsizei height, GLenum format, GLenum type, void* pixels) { - // Note: Negative widths and heights are not handled here but are handled - // by the service side so the glGetError wrapping works. if (width < 0 || height < 0) { SetGLError(GL_INVALID_VALUE); return; @@ -649,6 +647,13 @@ void GLES2Implementation::ReadPixels( if (width == 0 || height == 0) { return; } + + // glReadPixel pads the size of each row of pixels by an ammount specified by + // glPixelStorei. So, we have to take that into account both in the fact that + // the pixels returned from the ReadPixel command will include that padding + // and that when we copy the results to the user's buffer we need to not + // write those padding bytes but leave them as they are. + typedef gles2::ReadPixels::Result Result; Result* result = static_cast<Result*>(result_buffer_); int8* dest = reinterpret_cast<int8*>(pixels); @@ -670,12 +675,18 @@ void GLES2Implementation::ReadPixels( SetGLError(GL_INVALID_VALUE); return; } + // Check if we have enough space to transfer at least an entire row. if (padded_row_size <= max_size) { // Transfer by rows. + // The max rows we can transfer. GLint max_rows = max_size / padded_row_size; while (height) { + // Compute how many rows to transfer. GLint num_rows = std::min(height, max_rows); - GLsizeiptr part_size = num_rows * padded_row_size; + // Compute how much space those rows will take. The last row will not + // include padding. + GLsizeiptr part_size = + unpadded_row_size + (padded_row_size * std::max(num_rows - 1, 0)); void* buffer = transfer_buffer_.Alloc(part_size); *result = 0; // mark as failed. helper_->ReadPixels( @@ -687,10 +698,15 @@ void GLES2Implementation::ReadPixels( if (*result == 0) { return; } - memcpy(dest, buffer, part_size); + // We have to copy 1 row at a time to avoid writing pad bytes. + const int8* src = static_cast<const int8*>(buffer); + for (GLint yy = 0; yy < num_rows; ++yy) { + memcpy(dest, src, unpadded_row_size); + dest += padded_row_size; + src += padded_row_size; + } transfer_buffer_.Free(buffer); yoffset += num_rows; - dest += part_size; height -= num_rows; } } else { |